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Glossary of Chemical Terms
 

GLOSSARY (with definitions) of vocabulary terms frequently used by the EPA in their environmental guidelines and other literature,  lawyers, chemists,  laboratories,  environmental companies,  data validation workers,  field sampling collectors, chemical bottle supply companies,  chemistry students,  research scientists, scientific expert witnesses, etc in discussing soil samples, water samples, air or gas samples. 

 

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z 
 

abiotic – not relating to living things, not alive.

absorbance – a measure of the decrease in incident light passing through a sample into a detector.

absorption – 1) The process by which one substance is taken into the body of another substance.  2) The penetration of molecules or ions of one or more substances (gas, liquid or solid) into the interior of another substance.  For example, in hydrated bentonite (a type of clay),  the water that is held between the mica-like layers (held within the clay) is the result of absorption.

acceptance criteria — specified limits placed on characteristics of an item, process, or service

defined in requirements documents. (ASQC Definitions)

acceptance windows — the quantitative range that is between the lower acceptance limit and the upper acceptance limit.

Accepted Limit (AL)  -- Concentration value for an analyte corresponding to a regulatory limit or

guideline value which forms the purpose for the analysis, e.g. MRL, MPL; trading standard, target concentration limit (dietary exposure assessment), acceptance level (environment) etc. For a substance without an MRL or for a banned substance there may be no AL (effectively it may be zero or there may be no limit ) or it may be the target concentration above which detected residues should be confirmed (action limit or administrative limit).

accuracy — a measure of the closeness of an individual measurement or the average of a number of measurements  to the true value. Accuracy includes a combination of random error (precision) and systematic error (bias) components that are due to sampling and analytical operations; the EPA recommends using the terms “precision” and “bias”, rather than “accuracy,” to convey the information usually associated with accuracy.

activity — an all-inclusive term describing a specific set of operations of related tasks to be performed, either serially or in parallel (e.g., research and development, field sampling, analytical operations, equipment fabrication), that, in total, results in a product or service.

adsorption – the process by which a gas, vapor, dissolved material or very small particle adheres to the surface of a solid due to chemical or physical forces; the attraction and adhesion of ions from an aqueous solution to the solid soil or rock surfaces with which they are in contact.

aliquot – a measured portion of a sample taken for analysis.

analyte — a target analyte is an environmental compound or element that is being measured or identified in a chemical test to satisfy project-specific data objectives. Target analytes are distinguished from compounds or elements analyzed solely for the purposes of quality control (e.g., surrogates, matrix spikes and laboratory control samples). For brevity, target analytes are often referred to as analytes. The element of interest.

analyte homogeneity (in sample)  -- Uniformity of dispersion of the analyte in matrix. The variability in analytical results arising from sample processing depends on the size of analytical portion. The sampling constant describes the relationship between analytical portion size and the expected variation in a well mixed analytical sample: KS = w (CVSp) , where w is the mass of analytical portion and CVSp is the coefficient of variation of the analyte concentration in replicate analytical portions of w (g)which are withdrawn from the analytical sample.

analytical portion—A representative quantity of material removed from the analytical sample, of proper size for measurement of the residue concentration.

analytical sample  -- The material prepared for analysis from the laboratory sample, by separation of the portion of the product to be analysed and then by mixing, grinding, fine chopping, etc., for the removal of analytical portions with minimal sampling error.

assessment — the evaluation process used to measure the performance or effectiveness of a

system and its elements. As used here, assessment is an all-inclusive term used to denote any of

the following: audit, performance evaluation, management systems review, peer review,

inspection, or surveillance.

audit (quality) — a systematic examination to determine whether quality activities, systems and

related results comply with planned arrangements and whether these arrangements are implemented effectively and are suitable to achieve objectives.

auditor — a person qualified to perform audits.

Background concentrations or levels: average presence in the environment (USEPA).  concentrations of contaminants detected in environmental samples from various media on the site or in the area of the site that have not been affected by site operations. These concentrations may reflect the natural occurrence of elements, as in the case of metals in soil. They may also reflect the widespread presence of compounds resulting from a variety of industrial and commercial activities, as in the case of PAHs in surface soils in urban areas.

@ Regional background concentrations—usually apply to soil and reference data from a resource such as Shacklette and Boerngen (1984).

@ Site-specific background concentrations—reference actual samples collected on the site or in the area of the site. Examples of such samples are ground water samples from a monitoring well upgradient of the site or surface soil samples from an area that has not been affected by onsite operations.

bench sheets — the forms used to record routine measurements and observations for toxicity tests.

BFB Instrument Performance Check –4 bromofluorobenzene is the  compound chosen to establish mass spectral instrument performance for volatile analysis. Ion Abundance normalized to a nominal base,  /z 95.

BFB spectrum – obtained from chromatographic peaks that should be free from coelution problems.

bias — the systematic or persistent distortion of a measurement process, which causes errors in one direction (i.e., the expected sample measurement is different from the sample’s true value).

blank — a sample subjected to the usual analytical or measurement process to establish a zero baseline or background value. Sometimes used to adjust or correct routine analytical results. A sample that is intended to contain none of the analytes of interest. A blank is used to detect contamination during sample handling, preparation, and/or analysis.

boring  -- a cylindrical hole advanced into the ground, usually made by drilling.

calibration drift — the deviation in instrument response from a reference value over a period of

time before recalibration.

calibration — comparison of a measurement standard, instrument, or item with a standard or

instrument of higher accuracy to detect and quantify inaccuracies and to report or eliminate those inaccuracies by adjustments.

Calibration Check Compounds (CCC)  -- term used in conjunction with Method 8260 (EPA/SW-846) to refer to the compounds in which the percent relative standard deviation is evaluated against method-prescribed criteria to decide the validity of a calibration.

Calibration Standards (CAL) --  a set of solutions prepared from the primary standards solution with the internal standards and surrogate analytes as appropriate, used to calibrate the instrument response with respect to analyte concentration.

case – A usually predetermined number of samples collected over a given time period from a particular. case numbers are assigned by the Sample Management Office (SMO). A Case consists of one or more Sample Delivery Groups (SDGs). 

CAS number – CAS Registry Numbers (often referred to as CAS RNs or CAS Numbers) are unique identifiers for chemical substances. A Registry Number itself has no inherent chemical significance but provides an unambiguous way to identify a chemical substance or molecular structure when there are many possible systematic, generic, proprietary, or trivial names.

certification — the process of testing and evaluation against specifications designed to document, verify, and recognize the competence of a person, organization, or other entity to perform a function or service, usually for a specified time.

chain of custody — an unbroken trail of accountability that ensures the physical security of samples, data, and records.

characteristic — any property or attribute of a datum, item, process, or service that is distinct, describable, and/or measurable.

collaborative study  (analytical method) --  Inter-laboratory study in which all laboratories follow the same written protocol for the test method and use similar equipment to quantify the analyte(s) in sets of identical test samples. The reported results are used to estimate the performance characteristics of the method. Usually these characteristics are within-laboratory and between-laboratory precision, and when necessary and possible, other pertinent characteristics such as systematic error, recovery, internal quality control parameters, sensitivity, limit of determination, and applicability. Also called method-performance study. (See “Protocol for the Design, Conduct and Interpretation of Method Performance Studies”, Pure & Appl. Chem. 67 (1995) 331-343).

collocated samples — two or more portions collected at the same point in time and space so as to be considered identical. These samples are also known as field replicates and should be identified as such.

completeness — evaluates whether all data necessary to perform validation analysis were collected.

compliance — the extent that adherence to SOPs, QAPP, and/or contractual requirements were

followed, achieved, and/or completed successfully, and that conditions under which the data were

recorded also met the requirements.

confirmatory method  -- Methods that provide complete or complementary information enabling the analyte to be identified with an acceptable degree of certainty [at the Accepted Limit or level of interest].

conformance — an affirmative indication or judgment that a product or service has met the requirements of the relevant specification, contract, or regulation; also, the state of meeting the requirements.

consistency — determining whether performing data collection procedures across different collection sites (if applicable) and of data reported in multiple places were done in a similar manner.

continuing calibration blank (CCB) — a blank (zero) standard that is analyzed at a specified rate (e.g., every ten samples) to detect any carryover contamination or instrument drift.

continuing calibration verification (CCV) — a calibration standard that is analyzed at a specified rate (e.g., every ten samples) to verify instrument stability and performance.

contractor — any organization or individual contracting to furnish services or items or to perform work.

control limits (upper and lower) — in statistical quality control, the limits of acceptability shown on control charts; regions outside control limits are defective.

control sample A QC sample introduced to the analytical process to allow

evaluation of the measurement system performance.

corrective action — any measures taken to rectify conditions adverse to quality and, where possible, to preclude their recurrence.

correctness — a mechanical, objective check that data collection plans and protocols have been

followed and that basic operations and calculations were performed using properly-documented

and correctly-applied algorithms.

critical difference—Value below which the absolute difference between two single test results may be expected to lie with a specified probability. May be determined under conditions of repeatability or reproducibility. ISO 5725-1986 and Thompson and Wood PAC 67. 649-669, 1995.

custodians — one entrusted with guarding and keeping property, samples or records.

data qualifiers – symbols added as a suffix to analytical results used to flag data.

data usability — the process of ensuring or determining whether the quality of the data produced

meets the intended use of the data.

Data Usability Review – conducted by a reviewer to ensure that the data are usable for the Purpose specified in the project DRO.

Data Usability Summary (DUS) – results of a Data Usability Review.

data quality — the appropriate measurement, collection and use of data.

Data Quality Assessment (DQA): the scientific and statistical evaluation of data to determine if data obtained from environmental operations are of the right type, quality, and quantity to support their intended use. The five steps of the DQA Process include: 1) reviewing the DQOs and sampling design, 2) conducting a preliminary data review, 3) selecting the statistical test, 4) verifying the assumptions of the statistical test, and 5) drawing conclusions from the data.

Data Quality Objectives (DQOs) -- Qualitative and quantitative statements regarding the design and management of the effort to support appropriate collection and use of data. DQOs define the data to be collected, determine the most appropriate condition from which to collect the data, and specify the criteria which define the quality and quantity of the data to be collected.

data quality objectives process  -- A systematic strategic planning tool based on the scientific process that identifies and defines the type, quality, and quantity of data needed to satisfy a specified use. The elements of the process include the following steps:

·         Define the problem concisely;

·         Identify the decision to be made;

·         Identify the key inputs to that decision;

·         Define the boundaries of the study;

·         Develop the decision rule;

·         Specify tolerable limits on potential decision errors; and

·         Select the most resource efficient data collection design.

DQOs are the qualitative and quantitative outputs from this process.

Data Validation  -- An evaluation of the technical usability of the verified data with respect to the planned objectives or intention of the project. In addition, data validation can provide a level of overall confidence in the reporting of the data based on the methods used.

Data Verification – A  consistent, systematic process that determines whether the data have been collected in accordance to the specification of the Quality Assurance Project Plan with respect to compliance, correctness, consistency, and completeness as compared to a standard or contract.

Decision Limit..  (Cα)  -- Limit at which it can be decided that the concentration of the analyte present in a sample truly exceeds that limit with an error probability of α (false positive). In the case of substances with zero AL, the Cα .... is the lowest concentration level, at which a method can discriminate with a statistical probability of 1 - α whether the identified analyte is present. The Cα .... is equivalent to the limit of detection (LOD) under some definitions (usually for α  = 1%). In the case of substances with an established AL, the Cα .... is the measured concentration, above which it can be decided with a statistical probability of 1 - α  that the identified analyte content is truly above the AL.

decontamination – removal of harmful substances from exposed individuals, rooms and furnishings in buildings, or the exterior environment.

decomposition – the breakdown of matter by bacteria and fungi, changing the chemical makeup and physical appearance of materials.

Detection Capability (CCβ) -- Smallest true concentration of the analyte that may be detected, identified and quantified in a sample with a beta error (false negative). In the case of banned substances the Cβ ...is the lowest concentration at which a method is able to determine the analyte in contaminated samples with a statistical probability of 1 – ß. In the case of substances with an established MRL, Cβ ...is the concentration at which the method is able to detect samples that exceed this MRL with a statistical probability of 1 - ß. When it is applied at the lowest detectable concentration, this parameter is intended to provide equivalent information to the Limit of Quantitation (LOQ), but Cβ ...is always associated with a specified statistical probability of detection, and therefore it is preferred over LOQ..

detection limit --is used to verify (confirm and document) that the laboratory is actually able to detect and measure at the regulatory or decision limit.

Detection Test Mixture  -- Mixture of analytical standards which are suitable to check the conditions of chromatographic separation and detection. The detection test mixture should contain analytes which provide information for the selectivity and response factors for the detectors, and the inertness (e.g. characterized by the tailing factor Tf) and separation power (e.g. resolution Rs) of column, and the reproducibility of RRt. The detection test mixture may have to be column and detector specific. 

Discrete Sample --  a portion of material collected from a unique spatial location and submitted for chemical analyses. Discrete samples are collected when it is necessary to identify and quantify contamination at a specific location and time.

disinfectant – A chemical or physical process that kills patholgenic organisms in water.  Chlorine is often used to disinfect sewage treatment effluent, water supplies, wells, and swimming pools.

dispersant – A chemical agent used to break up concentrations of organic material such as spilled oil.

dispersion – Hydrodynamic dispersion: the process whereby a contaminant dissolved in groundwater spreads out in the direction coincident to and perpendicular to groundwater flow, causing the contaminant to become diluted; the sum of the effects of mechanical mixing and molecular diffusion on a dissolved contaminant that results in dilution of the contaminant.  The mixing results from differences in flow path length and velocity for different molecules.

dispersivity – a property that quantifies dispersion in a medium.

disposal – Final placement or destruction of toxic, radioactive, or other wastes; surplus or banned pesticides or other chemicals; polluted soils; and drums containing hazardous materials from removal actions or accidental releases. Disposal may be accomplished through use of approved secure landfills, surface impoundments, land farming, deep-well injection, ocean dumping, or incineration.

dissolved metals  -- Analyte elements which have not been digested prior to analysis and which will pass through a  0.45 omm filter.

dissolved oxygen (DO) – The oxygen freely available in water, vital to fish and other aquatic life and for the prevention of odors.

dissolved solids – Disintegrated organic and inorganic material in water. 

driller’s log -- The drillers record of material drilled through in the process of drilling a well.

dry weight – the weight of a sample based on percent solids. The weight after drying in an oven.

duplicate – identical splits of individual samples which are analyzed by the laboratory to test for method reproducibility.  Samples may be split in the laboratory.

duplicate samples — two samples taken from, and representative of, the same population and  carried through all steps of the sampling and analytical procedures in an identical manner. Duplicate samples are used to assess variance of the total method, including sampling and analysis. See also collocated sample.  Duplicate samples may also be generated in the lab instead of collected in the field. 

entity — that which can be individually described and considered, such as a process, product, item, organizations, or combination thereof.

environmental programs — an all-inclusive term pertaining to any work or activities involving the environment, including but not limited to: characterization of environmental processes and conditions; environmental monitoring; environmental research and development; the design, construction, and operation of environmental technologies; and laboratory operations on environmental samples.

environmental data operations — any work performed to obtain, use, or report information pertaining to environmental processes and conditions.

environmental data — any parameters or pieces of information collected or produced from measurements, analyses, or models of environmental processes, conditions, and effects of pollutants on human health and the ecology, including results from laboratory analyses or from experimental systems representing such processes and conditions.

environmental programs — a term pertaining to any work or activities involving the environment, including: characterization of environmental processes and conditions; environmental monitoring; environmental research and development; the design, construction, and operation of environmental technologies; and laboratory operations on environmental samples. Any measurements or information that describe environmental processes or conditions, or the performance of environmental technology,

environmental processes — manufactured or natural processes that produce discharges to or

that impact the ambient environment.

equipment blank – Checks field decontamination procedures.

equipment rinsate blank  -- A sample of analyte-free water poured over or through decontaminated field sampling equipment that is considered ready to collect or process an additional sample. The purpose of the equipment rinsate blank is to assess the adequacy of the decontamination process.

estimate — a characteristic from the sample from which inferences on parameters can be made.

Extractable Organics  -- semivolatiles (base/neutral and acid-extractable compounds) and pesticide/ polychlorinated biphenyl compounds that can be partitioned into an organic solvent from the sample matrix and are amenable to gas chromatography.

field (matrix) spike — a sample prepared at the sampling point (i.e., in the field) by adding a known mass of the target analyte to a specified amount of the sample. Field matrix spikes are used, for example, to determine the effect of the sample preservation, shipment, storage, and preparation on analyte recovery efficiency (the analytical bias).

field blank — a sample used to provide information about contaminants that may be introduced during sample collection, storage, and transport; a clean sample, carried to the sampling site, exposed to sampling conditions, returned to the laboratory, and treated as an environmental sample. It has its own unique EPA sample number and checks for cross-contamination during sample collection, sample shipment, and in the laboratory. A Field Blank includes trip blanks, rinsates, equipment blanks, etc.

field duplicate – Checks reproducibility of laboratory and field procedures and indicates non-homogeneity.

field duplicates—Field duplicates are analyzed as they are presented to the laboratory for analysis. Although they are ‘labeled’ as duplicates, a field duplicate is recognized as a unique, separate sample, and therefore is not used for in-house quality control purposes.

field QC sample – Used to detect for contamination or error in the field.

field replicate—a general term for field duplicates/triplicates, field splits, or field spikes. Samples may be homogenized prior to splitting into replicate samples. Each replicate is containerized, handled, and analyzed in an identical manner. Used to evaluate the precision of handling, shipping, storage, preparation, and analysis.

field sample – Primary sample material from which other samples, such as duplicates or split samples, are derived.  A field sample can be prepared in the field and sent for analysis in one or multiple containers, and is identified by a n unique EPA sample number.

Field Sampling Plan (FSP)  -- the portion of the Sampling Analysis Plan that defines the field activities; includes all requirements for sampling, field documentation, onsite chemical analysis, sample packaging and shipping, etc.

filtrate --  a filtered liquid.

finding — an assessment conclusion that identifies a condition having a significant effect on an item or activity. An assessment finding may be positive or negative, and is normally accompanied by specific examples of the observed condition.

fortification – another word for spiking.

Gas Chromatography—A process in which the components of a mixture are separated from one another by volatilizing the sample mixture into a carrier gas stream that is passing through and over a bed of packing solid support. Different components move through at different rates  depending on their size and affinity toward the solid support. Elution from the column occurs at different rates to the various detectors where the components are measured based on thermal conductivity changes, density differences, or ionization detectors. The primary components of a gas chromatograph include injection port, column, integrator/data system, and detectors.

Gas Chromatography/Mass Spectroscopy (GC/MS)  -- two distinct analytical techniques used to separate and identify organic compounds: the GC is used for the separating portion and the MS is used as the detection portion of an analysis. Both techniques are typically performed by a single instrument.

grab sample—an individual sample collected from a single location at a specific time. Samples are collected and placed in the appropriate sample containers with no mixing.

guidance — a suggested practice that is not mandatory, intended as an aid or example in complying with a standard or requirement

Hazardous/Nonhazardous --  the following terms are correct:

@ Hazardous waste (RCRA)--as defined in 40 CFR 261, byproducts of society that can pose a

substantial or potential hazard to human health or the environment when improperly managed.

Refers to both wastes listed in the referenced section and wastes demonstrating any of the four

hazardous characteristics (ignitability, corrosivity, reactivity, and toxicity) identified in the

referenced section.

@ Hazardous substance (CERCLA)--encompasses not only RCRA hazardous wastes, but also includes substances and pollutants listed under the Clean Water Act; hazardous air pollutants listed under the Clean Air Act; any substance with respect to which the USEPA has taken action under the Toxic Substances Control Act; and elements, compounds, mixtures, solutions, and substances (to be identified by the USEPA under CERCLA) which, when released into the environment, may present substantial danger to the public welfare or the environment.

@ Hazardous material (Department of Transportation)--refers to materials contaminated by any

substance that is listed in the appendix to 49 CFR 172.101 and that exceeds the reportable quantity

criteria identified in this appendix.

@ Nonhazardous—if used, clarify whether it is used as the opposite of one or all of these terms, or whether it refers to the absence of toxic characteristics as defined by risk assessment techniques, etc.

heavy metals --  in reference to environmental sampling, typically identified as the following trace inorganics: cadmium, lead, mercury, silver, etc. (all metals of health concern). Heavy metals can cause biological damage if consumed at low concentrations and tend to accumulate in the food chain.

heterogeneous  -- the quality of containing dissimilar parts within the composition of the media.

high concentration sample – A sample whose concentrations may not be suitable for analysis using the low or low/medium concentration analytical methods (e.g., samples collected directly from drums, pits, ponds, lagoons, or areas where no dilution of waste is evident). Note: High concentration sample analyses are not available under any current CLP Statement of Work (SOW).

High-Performance Liquid Chromatography (HPLC): -- an analytical technique used for separating and

identifying compounds not amenable to gas chromatography.

holding time — the period of time a sample may be stored prior to its required analysis. While exceeding the holding time does not necessarily negate the veracity of analytical results, it causes the qualifying or ‘flagging’ of any data not meeting all of the specified acceptance criteria. Holding time can also refer to the amount of time a sample was actually stored, whether it meets the designated threshold value for holding or surpasses it.

homogeneous—the quality of uniform composition.

homogenized sample—a sample collected from a single location at a specific time, but mixed to ensure representativeness prior to containerizing. This technique is not suitable for volatile organic samples.

Hydrogeologic Investigation --  a systematic study of the interrelationships that exist between geology and the associated ground and surface water.

incurred residue—Residues of an analyte in a matrix arising by the route through which the trace levels would normally be expected, as opposed to residues from laboratory fortification of samples. Also weathered residue.

individual method—Method which is suitable for determination of one or more specified compounds. A separate individual method may be needed, for instance to determine some metabolite included in the residue definition of an individual pesticide or veterinary drug.

Hydrogeology  -- the study of the interrelationships of geologic materials and processes with water, especially groundwater.

Hydrology --  the study of the occurrence, distribution, and chemistry of all waters of the earth.

infiltration --  the penetration of water through the ground surface into subsurface soil or the penetration of water from the soil into sewer or other pipes through defective joints, connections, or manhole walls.

initial calibration verification (ICV) — the first blank (zero) standard analyzed to confirm the initial instrument calibration.

initial calibration blank (ICB) — the first blank (zero) standard analyzed to confirm the initial instrument calibration.

Initial (Continuing) Calibration Blank (ICB/CCB) -- a volume of ASTM D 1193 Type II (polished) water prepared in the same manner as standards used to flush the analytical system.

Initial (Continuing) Calibration Verification Standard (also instrument check standard) (ICV/CCV): a USEPA-certified multielement standard or independently prepared multielement standard solution used to verify the accuracy of the initial calibration. This standard prepares all elements at solutions of known concentrations equivalent to the midpoint of their respective calibration curves and must be run at each wavelength used in the inductively coupled plasma analysis.

Inorganic Chemicals: chemical substances of mineral origin, not of basically carbon structure.

inspection — an activity such as measuring, examining, testing, or gauging one or more characteristics of an entity and comparing the results with specified requirements in order to establish whether conformance is achieved for each characteristic.

instrument blank - A 25.0 ml aliquot of reagent water that is carried through the entire analytical procedure and is analyzed following highly contaminated samples containing target compounds that exceed the initial calibration range. The instrument blanks are used to determine if contamination is introduced from a previous sample and the level associated with the analytical instrument. All blanks are spiked with internal standards and surrogate compounds and blank analysis must meet internal standard and surrogate compound criteria. Instrument blanks are analyzed after a sample/dilution which contains a target compound at a concentration greater than 25 ug/L (ketones 125 ug/L) or a non-target compound at a concentration greater than 100 ug/L or saturated ions from a compound (excluding peaks in the solvent front).

integrity — an unimpaired condition or soundness. A quality or state of being complete or 24 undivided.

Interference (Interelement) Check Standard (ICS or IEC) -- a solution containing both interfering and analyte elements of known concentrations used to verify background and/or interelement interferences, so that appropriate correction factors are utilized to compensate.

Internal Standards (IS) -- Compounds added to every standard, blank, sample, matrix duplicate, matrix spike, matrix spike duplicate, etc., at a known concentration, prior to analysis by GC or GC/MS when using internal standard calibration and quantitation techniques. Internal standards are used as the basis for quantitation of the target compounds.

internal standard – a known amount of an organic compound added to the sample prior to analysis. The IS provides a method for quantifying chromatographic data.

item — An all-inclusive term used in place of the following: appurtenance, facility, sample, assembly, component, equipment, material, module, part, product, structure, subassembly, subsystem, system, unit, documented concepts, or data.

Laboratory Certification Statement – Accompanies SDG, along with C-O-C and Narrative and authorizes release of sample data results.

Laboratory Data Review – conducted by the lab to ensure that the method requirements were met. Consists of: 1) Laboratory Review Checklist, 2) associated Exception Reports, and 3) required reportable data.

lab duplicates --Two aliquots of the same sample are taken within the laboratory and analyzed as different samples using the same procedure. Laboratory duplicates provide a means of monitoring precision.

laboratory fortified blank (LFB) --  a term used in conjunction with EPA/600/4-88/039 method 524.2, which describes an aliquot of reagent water to which known quantities of the method analytes are added in the laboratory. The LFB is similar to an aqueous LCS.

Laboratory Review Checklist (LRC) – completed by lab. Reveals magnitude of any potential inaccuracy, direction of potential bias, and other effects on the quality of the data.

laboratory sample  -- The sample as received at the laboratory (not including the packaging).

level of confidence — the probability associated with a confidence interval; the probability that the interval contains a given parameter or characteristic. for planning, implementing, and assessing work.

Limit of Detection (LD) -- Smallest concentration where the analyte can be identified. Commonly defined as the minimum concentration of analyte in the test sample that can be measured with a stated probability that the analyte is present at a concentration above that in the blank sample.

Limit of Quantitation (LOQ) -- Smallest concentration of the analyte that can be quantified. Commonly defined as the minimum concentration of analyte in the test sample that can be determined with acceptable precision (repeatability) and accuracy under the stated conditions of the test

Lowest Calibrated Level (LCL) -- Lowest concentration of analyte detected and measured in calibration of the detection system

(m/z): mass-to-charge ratio. Synonymous with (m/e).

management system — a structured non-technical system describing the policies, objectives, principles, organizational authority, responsibilities, accountability, and implementation plan of an organization for conducting work and producing items and services.

matrix-- the material of which the sample to be analyzed is composed. Typically, refers to water, soil/ sediment, or other environmental medium. “Matrix” is NOT synonymous with “phase” (liquid or solid).

matrix duplicate/laboratory duplicate (DUP): two representative aliquots of the same sample matrix subjected to identical analytical procedures in order to assess the procedural precision of the method through the calculation of relative percent difference (%RPD).

Matrix-matched Calibration—Calibration using standards prepared in an extract of the commodity analysed (or of a representative commodity).

Matrix-matched Calibration—Calibration using standards prepared in an extract of the commodity analysed (or of a representative commodity). The objective is to compensate for the effects of co-extractives on the determination system. Such effects are often unpredictable, but matrix-matching may be unnecessary where co-extractives prove to be of insignificant effect.

matrix spike — a sample prepared by adding a known mass or volume of a target analyte to a specified amount of matrix sample for which an independent estimate of the target analyte concentration is available. Spike samples are used, for example, to determine the effect of the matrix on a method’s recovery efficiency.

Matrix spike duplicate (MSD) – Sample required by the laboratory’s contract to check the accuracy and precision of organic analyses.  It is a second aliquot of the same matrix as the matrix spike that is spiked to determine the precision of the method.

may — permission but not a requirement.

Measurement Quality Objectives (MQOs): Specific goals that clearly describe the performance requirements for a measurement system. MQOs specify acceptance criteria for Data Quality Indicators, such as selectivity, sensitivity, detection limits, bias, precision, representativeness, comparability, and completeness for the collected data.

medium/media --  refers to the basic material composing an environmental sample or an environment of regulatory concern, i.e., water, soil, or air. “Medium” is singular; “media” is plural. This term derives from the conventional definition: “the element (earth, water, air, or fire) that is the natural habitat of an organism).”

memory effects — the effect that a relatively high concentration sample has on the measurement of a lower concentration sample of the same analyte when the higher concentration sample precedes the lower concentration sample in the same analytical instrument.

metadata -- data that describes other data.  Among many other data elements, metadata includes: collection method; instrument type; instrument accuracy; instrument precision; data format; unit conventions; variable naming conventions; QA/QC flags.

method — a body of procedures and techniques for performing an activity (e.g., sampling, chemical analysis, quantification), systematically presented in the order in which they are to be executed.

method blank — a sample prepared to represent the sample matrix as closely as possible and analyzed exactly like the calibration standards, samples, and quality control (QC) samples. Results of method blanks provide an estimate of the within-batch variability of the blank response and an indication of bias ntroduced by the preparation and analytical procedure. Also called Laboratory blank.

method blank - A 25.0 mL aliquot of reagent water that is carried through the entire analytical process to determine the levels of contamination associated with the processing and analysis of samples. All blanks are spiked with internal standards and surrogate compounds and blank analysis must meet internal standard and surrogate compound criteria. The method blank must be analyzed at least once during every 12 hour time period on each GC/MS system used for volatile analysis.

Method Detection Limits (MDL) — the minimum concentration of a substance that can be measured and reported with 99% confidence that the analyte concentration is greater than zero and is determined from analysis of a sample in a given matrix containing the analyte.

Method of Standard Additions (MSA): the method of standard addition may be required to compensate for matrix effects. This technique should not be used for interferences that cause baseline shift. The standard-addition technique involves the analysis of the unknown sample and unknown plus known amounts of standard with extrapolation of this internal calibration curve to the baseline.

Method Quantitation Limit (MQL) –Limit(MQL) -- The value at which the laboratory has demonstrated the ability to reliably quantitate target analytes for the method performed. In absence of project specific requirements, the MQL must be set using the lowest standard used by the laboratory for initial calibration (or initial calibration verification) for each target analyte.

Method Validation—Process of verifying that a method is fit for purpose.

mid-range check — a standard used to establish whether the middle of a measurement method’s calibrated range is still within specifications.

Multi Residue Method, MRM  -- Method which is suitable for the identification and quantitation of a range of analytes, usually in a number of different matrices.

must — a requirement that has to be met.

Mixed Waste  -- waste material containing hazardous chemical and radioactive constituents.

Multimedia: containing or involving more than one medium.

National Priority List (NPL)-- the USEPA’s list of the most serious uncontrolled or abandoned hazardous waste sites identified for possible long-term remedial action under Superfund. The list is based primarily on the score a site receives from the Hazard Ranking System. USEPA is required to update the NPL at least once a year.

negative result  -- A result indicating that the analyte is not present at or above the lowest calibrated level. (see also Decision Limit and Limit of Detection)

objective evidence — any documented statement of fact, other information, or record, either quantitative or qualitative, pertaining to the quality of an item or activity, based on observations, measurements, or tests which can be verified.

observation — an assessment conclusion that identifies a condition (either positive or negative) which does not represent a significant impact on an item or activity. An observation may identify a condition which does not yet cause a degradation of quality.

organization — a company, corporation, firm, enterprise, or institution, or part thereof, whether incorporated or not, public or private, that has its own functions and administration.

outlier — an extreme observation that is shown to have a low probability of belonging to a specified data population.

parameter — a quantity, usually unknown, such as a mean or a standard deviation characterizing a population. Commonly misused for “variable,” “characteristic,” or “property.”

Percent Relative Standard Deviation (%RSD) -- The % RSD for each compound is a measure of the linearity of the calibration curve.

performance based measurement system (PBMS) --   A set of processes wherein the data quality needs, mandates, or limitations of a program or project are specified and serve as criteria for selecting appropriate methods to meet those needs in a cost-effective manner.

performance criteria—criteria that define the quality of the data relative to the limits of uncertainty allowed for a measurement (bias, precision, minimum detection).

Performance Verification—Sets of quality control data generated during the analysis of batches of samples to support the validity of on-going analyses. The data can be used to refine the performance parameters of the method.

peer review — a documented critical review of work generally beyond the state of the art or characterized by the existence of potential uncertainty. The peer review is conducted by qualified individuals (or organization) who are independent of those who performed the work, but are collectively equivalent in technical expertise (i.e., peers) to those who performed the original work. The peer review is conducted to ensure that activities are technically adequate, competently performed, properly documented, and satisfy established technical and quality requirements. The peer review is an in-depth assessment of the assumptions, calculations, extrapolations, alternate interpretations, methodology, acceptance criteria, and conclusions pertaining to specific work and of the documentation that supports them. Peer reviews provide

an evaluation of a subject where quantitative methods of analysis or measures of success are unavailable or undefined, such as in research and development.

pH: --a numerical designation of relative acidity or basicity (alkalinity). A pH of 7 indicates neutrality; lower values indicate increasing acidity; higher values indicate increasing alkalinity.

Physical Soil Analysis: an analysis used to determine the physical and engineering properties of a soil. Possible analyses may include particle size, dry weight, Atterberg limits, pH, redox potential, mineral class, organic carbon and clay content, density, soil porosity, compaction, and consolidation.

Positive Result  -- A result indicating the presence of the analyte with a concentration at or above the lowest calibrated level. (see also Detection Capability)

precision — a measure of mutual agreement among individual measurements of the same property, usually under prescribed similar conditions, expressed generally in terms of the standard deviation. Closeness of agreement between independent test results obtained under stipulated conditions.

preparation blank (PB) — a laboratory quality control sample which consists of analyte-free matrix processed through the appropriate sample preparation and analysis procedure to document that contaminants re not being introduced to the analytical system during preparation.

Preservation: methods used to retard degradation of chemical analytes within samples by inhibiting decomposition by biological action and chemical reactions, and reducing sorption effects. Methods include limiting headspace; chemical, acid, or base addition; protection from light, cooling, etc.

professional judgment: the ability of a single person or team to draw conclusions, give opinions, and make interpretations based on measurement results, knowledge, experience, literature, and other sources of information.

Purge-and-Trap Device: analytical technique used to isolate volatile (purgeable) organics by stripping the compounds from water or soil slurry by a stream of inert gas, trapping the  compounds on an adsorbent such as a porous polymer trap, and thermally desorbing the trapped compounds onto a gas chromatographic column.

probit analysis — a procedure used in dosage-response studies to avoid obtaining negative response alues to certain dosages; five is added to the values of the standardized variate which is assumed to be normal; he term is a contraction or probability unit.

procedure — a specified way to perform an activity.

process — a set of interrelated resources and activities that transforms inputs into outputs. Examples of processes include analysis, design, data collection, operation, fabrication, and calculation.

project — an organized set of activities within a program. Specifically, activity in which measurements are used to further a goal.

quality control (QC) — the overall system of technical activities that measures the attributes and performance of a process, item, or service against defined standards to verify that they meet the stated requirements established by the customer; operational techniques and activities that are used to fulfill requirements for quality.

quality system — structured and documented management system describing the policies, objectives, principles, organizational authority, responsibilities, accountability, and implementation plan of an rganization for ensuring quality in its work processes, products (items) and services. The quality system provides the framework for planning, implementing, and assessing work performed by the organization and or carrying out required QA and QC.

quality management — that aspect of the overall management system of the organization that determines and implements the quality policy. Quality management includes strategic planning, allocation of esources, and the systematic activities (e.g., planning, implementation, and assessment) pertaining to the quality system.

quality assurance (QA) — an integrated system of management activities involving planning, implementation, assessment, reporting, and quality improvement to ensure that a process, item, or service is of the type and quality needed and expected by the customer.

Quality Assurance Project Plan (QAPP) — a formal document describing in comprehensive detail the necessary QA, QC, and other technical activities that must be implemented to ensure that the results of the work performed will satisfy the stated performance criteria.

quality control (QC) sample — an uncontaminated sample matrix spiked with known amounts of analytes from a source independent of the calibration standards. Generally used to establish intra-laboratory or analyst-specific precision and bias or to assess the performance of all or a portion of the measurement system.

quality — the totality of features and characteristics of a product or service that bear on its ability to meet the stated or implied needs and expectations of the user.

Quantitation Limit (QL): the minimum concentration of an analyte in a specific matrix that can be

identified and quantified within specified limits of accuracy or precision.

Quantitative Method—A method capable of producing results, expressed as numerical values in appropriate units, with accuracy and precision which fit for the purpose. The degree of precision and trueness must be specified.

raw data package — a collection of data that has not been processed.

reagent — a substance used (as in detecting or measuring a component, in preparing a product or in eveloping photographs) because of its chemical or biological activity.

reagent blank  -- Complete analysis made without the inclusion of sample materials for QC purpose.

record (quality) — a document that furnishes objective evidence of the quality of items or activities and that has been verified and authenticated as technically complete and correct. Records may include photographs, drawings, magnetic tape, and other data recording media.

recovery — the act of determining whether or not the methodology measures all of the analyte contained in a sample

Redox -- oxidation-reduction potential.

Reference Material - Material one or more of whose analyte concentrations are sufficiently homogeneous and well established to be used for the assessment of a measurement method, or for assigning values to other materials. In the context of this document the term “reference material” does not refer to materials used for the calibration of apparatus.

Reference Method—Quantitative analytical method of proven reliability characterised by well established trueness, specificity, precision and detection power. These methods will generally have been ollaboratively studied and are usually based on molecular spectrometry. The reference method status is only valid if the

method is implemented under an appropriate QA regime.

Reference Procedure—Procedure of established efficiency. Where this is not available, a reference

procedure may be one that, in theory, should be highly efficient and is fundamentally different from that under test.

Regulatory Review – conducted by TNRCC to ensure TRRP rules were met.

Relative Response factor – A measure of the relative mass spectral response of an analyte compared to its internal standard.  The average or mean RRF is determined by the analysis of five different standard concentrations and is used in calculating a compound concentration in samples.

Repeatability  -- Precision under repeatability conditions, i.e. conditions where independent test results are obtained with the same method on replicate analytical portions in the same laboratory by the same operator using the same equipment within short intervals of time. (ISO 3534-1)

Representative Analyte  -- Analyte chosen to represent a group of analytes which are likely to be similar in their behavior through a multi-residue analytical method, as judged by their physico-chemical properties e.g. structure, water solubility, Kow, polarity, volatility, hydrolytic stability, pKa etc.

Represented Analyte  -- Analyte having physico-chemical properties which are within the range of properties of representative analytes.

Remedial Investigation (RI) -- a process undertaken to determine the nature and extent of the problem presented by the release of hazardous substances into the environment (EPA). The RI includes sampling and monitoring and gathering sufficient information to establish cleanup criteria to determine the necessity for remedial action and to support the evaluation of remedial alternatives. The RI process is usually considered to encompass obtaining resources required for the field investigation, the field investigation itself, and the RI report.

Reporting Limit  -- the project-specific threshold limit established for a project for which, below a numerical value, the data are reported as nondetect (U) and presented as less than (<) a numerical value. The threshold value below which the laboratory reports a result of “less than” or “not detected”.

Representativeness -- a qualitative measure of the extent to which a sample(s) acquired from a medium describes the chemical characteristics of that medium.

Reproducibility  -- the precision, usually expressed as variance, measures the variability among the results from replicates analysis.

Residual -- pertaining to a residue or remainder, as in “residual contaminations.” Amount of pollutant remaining in the environment after a natural or technological process has taken place, for example, the sludge remaining after initial wastewater treatment or particulates remaining in air after the air passes through a scrubbing or other pollutant removal process.

Resolution -- also known as separation, or percent resolution. The separation between peaks on a chromato-gram, calculated by dividing the depth of the valley between the peaks by the peak height of the smallest peak being resolved, and multiplied by 100. A Method criterion for peak resolution may be established based on peak tailing factors (Figure I-1), but is normally evaluated based on analyst judgment.

reproducibility  -- Closeness of agreement between results obtained with the same method on replicate analytical portions with different operators and using different equipment (within laboratory  reproducibility). Similarly, when the tests are performed in different laboratories the inter-laboratory reproducibility is obtained.

requirement — a formal statement of a need and the expected manner in which it is to be met.

reliable detection limit – Twice the MDL of the low limit, not greater than half the MQL.

research (basic) — a process, the objective of which is to gain fuller knowledge or understanding of the fundamental aspects of phenomena and of observable facts without specific applications toward processes or products in mind.

research (applied) — a process, the objective of which is to gain knowledge or understanding necessary for determining the means by which a recognized and specific need may be met.

sample custody — the method by which samples are tracked from collection to shipment or receipt by the laboratory.

sample prpreparation  -- The procedure used, if required, to convert the laboratory sample into the analytical sample, by removal of parts (soil, stones, bones, etc.) not to be included in the analysis.

sample processing  -- The procedure(s) (e.g. cutting, grinding, mixing) used to make the analytical sample acceptably homogeneous with respect to the analyte distribution, prior to removal of the analytical portion. The processing element of preparation must be designed to avoid inducing changes in the concentration of the analyte

Sample Quantitation Limit (SQL) – The limit at which the lab can reliably detect the chemical of choice.

sample tracking --sample handling and custody procedures not intended to satisfy legal or

evidentiary requirements, unlike a chain-of-custody.

Semi-volatile Organic Analyte (SVOA)  –  A compound amenable to analysis by extraction of the sample using an organic solvent. A term used synonymously with the term  Base/Neutral/Acid. (BSA) substance. .

screening method—A method used to detect the presence of an analyte or class of analytes at or above the minimum concentration of interest. It should be designed to avoid false negative results at a specified probability level (generally â = 5%). Qualitative positive results may be required to be confirmed by confirmatory or reference methods. See Decision Limit and Detection Capability.

selectivity  -- Measure of the degree to which the analyte is likely to be distinguished from other sample components, either by separation (e.g., chromatography) or by the relative response of the detection system.       

specificity—Extent to which a method provides responses from the detection system which can be considered exclusively characteristic of the analyte.

sensitivity — the capability of a method or instrument to discriminate between measurement responses representing different levels of a variable of interest.

Sensitivity -- a general term used to describe contract method detection/quantitation/reporting limits established to meet project-specific data quality objectives, or the capability of a method or instrument to discriminate between small differences in analyte concentration.

Serial Dilution -- when a new or unusual matrix is encountered, a series of tests is recommended prior to release of results to verify that no matrix effects are occurring. The method recommends serial (1:4) dilution be run on samples with concentrations at least >10X instrument detection limit, with results agreeing within ± 10 percent of the original determination.

single blind PT  -- A proficiency test sample that is known to be a proficiency sample by members of the laboratory staff, but the actual composition of the sample, in terms of types and concentrations of analytes, is unknown (i.e., “blind”). Single blind PT samples may not be a good indicator of routine laboratory  performance, particularly when the laboratory has to reconstitute the sample from a concentrate.

sludge -- any heavy, slimy deposit, sediment, or mass.

Slug Test --an aquifer test conducted by causing an instantaneous change in the water level in a well. The recovery of the water level with time is measured.

Soil -- a natural aggregate of mineral grains with or without organic materials that can be separated by mechanical means.

Solids -- materials that tend to keep their form rather than to flow or spread out.

Split-spoon Sampler -- open-ended cylindrical tool used to collect samples by driving or pushing them into the ground. Split-spoon samplers have inside diameters ranging from 3 to 6.3 cm (1-3/8 to 2-1/2 in.) and usually consist of five parts, similar to a continuous barrel sampler.

span check — a standard used to establish that a measurement method is not deviating from its calibrated range.

spatial — relating to, occupying, or having the character of space.

specification — a document stating requirements and which refers to or includes drawings or

other relevant documents. Specifications should indicate the means and the criteria for determining conformance.

spike — a substance that is added to an environmental sample to increase the concentration of  target analytes by known amounts; used to assess measurement accuracy (spike recovery). Spike duplicates are used to assess measurement precision in cases where actual samples are not or cannot be duplicated.

Spikes—A spike is prepared by adding method analytes to an aliquot of sample in a known amount and is taken through the analytical process. The amount of analyte detected in the sample is subtracted from the spiked analysis and the percent recovery is calculated. All matrix spiking is done in duplicate.

Standard Addition—A procedure in which known amounts analyte are added to aliquots of a sample extract containing the analyte (its initially measured concentration being X), to produce new notional concentrations (for example, 1.5X and 2X). The analyte responses produced by the spiked aliquots and the original extract are measured and the analyte concentration in the original extract (zero addition of analyte) is determined from the slope and intercept of the response curve. Where the response curve obtained is not linear, the value for X must be interpreted cautiously.

standard deviation — a measure of the dispersion or imprecision of a sample or population distribution expressed as the positive square root of the variance and has the same unit of measurement as the mean.

standard operating procedure (SOP) — a written document that details the method for an operation, analysis, or action with thoroughly prescribed techniques and steps, and that is officially approved as the method for performing certain routine or repetitive tasks.

Storage Blank -- Consists of two 40 mL VOA vials filled with reagent water prepared by the laboratory when the first samples in the SDG are received. The vials are stored, under the same conditions, with the field samples. After all the samples in the SDG are analyzed, a 25.0 mL aliquot of the storage blank is analyzed to determine whether contamination was introduced during storage of the samples. All blanks are spiked with internal standards and surrogate compounds and blank analysis must meet internal standard and surrogate compound criteria. A minimum of one storage blank must be analyzed per SDG after all samples for that SDG have been analyzed.

Subsurface -- below the land surface.

Subsurface Investigation -- a systematic study of the physical and chemical properties of the geologic materials, groundwater, and any waste products present in the subsurface.

Subsurface Soil -- soil that underlies the defined limit of surface soil. Distinction between surface soil and subsurface soil is valid only when referring to risk posed by exposure of surface biota to contamination.

surrogate percent recoveries — the actual amount of surrogate analyte recovered as a result of the analysis divided by the known amount of surrogate introduced to the analytical system multiplied by 100.

surrogate — an organic compound which is similar to the target analyte(s) in chemical composition and behavior in the analytical process, but which is not normally found in environmental samples.

surrogate spike or analyte — a pure substance with properties that mimic an analyte of interest. It is unlikely to be found in environmental samples and is added to them to establish that the analytical method has been performed properly.

Suspended Metals  -- The concentration of metals determined in the portion of a sample that is retained on a  0.45-:m filter. (The concentration of suspended metals may also be calculated from the difference between the total metals sample results minus the dissolved metals sample results.)

systematic planning — a process that is based on the scientific method and uses a graded approach to insure that the level of detail in planning is commensurate with the importance and intended use of the work and available resources. task — defined or specified portion of a project.

Tailing factor  -- Measure of chromatographic peak asymmetry; at 10% peak height maximum, the ratio of the front and tail segments of peak width, when separated by a vertical line drawn through the peak  maximum.

technical usability — a technical assessment of an overall data set based on the results and the related quality control data to determine if the data “make sense” and are fit for use.

technical systems audit (TSA) — a thorough, systematic, on-site qualitative audit of facilities, equipment, personnel, training, procedures, record keeping, data validation, data management, and reporting aspects of a system.

temperature blank --  a container filled with water packaged along with the field samples to allow the receiving laboratory a mechanism to accurately measure the temperature of the cooler and associated samples upon receipt. The samples do not undergo any chemical analysis.

temporal — of or relating to time.

Tentatively Identified Compounds (TICs) -- compounds detected in environmental samples that are not method target analytes, internal standards, or surrogates. Typically 10 to 20 of the largest unidentified peaks are subjected to a mass spectral library search for tentative identification. An additional charge may be associated with this procedure.

Total Metals --  concentration of metals determined in an unfiltered water sample that is preserved (acidified) in the field and transported to the laboratory, and then follows a rigorous digestion.

Total Recoverable Metals --  </