Download TASC Laboratory

Chicago, Rockford, Edwardsville
312-573-8248
815-965-1106
618-656-7672
GLOSSARY of TERMS
Adulterated Specimen - A specimen containing a substance that is not a normal constituent or containing an
endogenous substance at a concentration that is not a normal physiological concentration.
Agency - Refers to the particular agency, program, service area, etc. responsible for the Client.
Analyte - A general term referring to the compound being tested. This could mean a fasting blood sugar or a
specific drug.
Assay - A general term referring to the testing process.
Chain of Custody - The process of verifying and documenting the client's identification and labeling the
specimen to insure is it only from the client, so that the test results are actually for the individual.
Client - Refers to the person who is providing the specimen for testing.
Collection - The process of obtaining a specimen from the Client. This may be "Observed" (actual viewing
of the urination into the container) or "Supervised" (restricted access to washroom and prohibited
water use).
Confirmation Test - When a sample tests positive, it may indicate recent drug usage. Typically, the greater
the usage, or closer to the usage time, the higher the result. However, a "false" positive can occur
when certain substances cross-react with the testing process. (Example: Codeine in cough medicine
versus cocaine) The Confirmation Test will "validate" the test result and well as differentiate
between the actual and false values. Some agencies split the sample into two containers and reserve
the second container or aliquot of the original specimen for confirmation only. (See also GC/MS)
Cut-Off Value Detection Time - The approximate interval between usage and when the drug will likely appear in the urine
sample. This varies with the amount used, length of time over which the drug was consumed and the
amount of liquids consumed to dilute the urine or if diuretics are used.
Dilute Specimen - A urine specimen with creatinine and specific gravity values that are lower than expected
for human urine.
Drop - Term sometimes used to refer to the collection of a urine specimen from a client.
Interference - Chemicals, foods, herbs and other drugs can "interfere" with the testing. Examples of
possible substances are listed in each of the specific drug information sheets.
GC/MS - This abbreviation stands for Gas Chromatography / Mass Spectrometer. This instrument has the
ability to physically separate various analytes (compounds) by their atomic weight and then assay
their individual concentrations.
Linearity - Many tests have a "Linear" relationship. This means the test equipment "readings" increase as
the concentration increases. "Linear Up To" means test accuracy is at its best up to a certain level.
Once above it, an error occurs with the higher the concentration of the drug.
748959060
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Doc. No. 18.323
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Chicago, Rockford, Edwardsville
312-573-8248
815-965-1106
618-656-7672
Metabolite - The body will break down food and drugs into smaller compounds for absorption. Fat in food
for example is broken down (metabolized) into fatty acids and glycerol. Thus the fatty acids and
glycerol are metabolites of fat. The same is true for the breakdown of drugs in the body.
Oxidizing Adulterant - A substance that acts alone or in combination to oxidize drugs or drug metabolites
to prevent detection, or effects the reagents used for the drug tests. Examples are bleach, pyridium,
nitrites, halogens, peroxidase and hydrogen peroxide.
Qualitative Results - The assay can only provide either a "Positive" or "Negative" result. An example is a
home pregnancy test. Such assays are adequate for a rapid screening while the client is "on-site".
Quantitative Results - The assay provides a number indicating the actual concentration is the analyte in the
sample. This method is the most accurate assay. (Like looking into a bowl of flour and knowing
exactly how much of what kind of flour (white, wheat, rye, soy, etc.) is present.
SAMHSA - Refers to the Substance Abuse and Mental Health Services Administration department of the
U.S. Government. (This program was formerly known as NIDA)
Semi-Quantitative Results - The assay provides a number to estimate the concentration of the analyte in the
sample. This estimate is very accurate when the results are well into the Negative or Positive range.
(Like looking into a bowl and determining if its flour, cornstarch or salt. You know about how much
is there, but not the specific kind of product. )
Specimen - Refers to the urine sample collected for testing.
Substituted Specimen - A urine specimen with test gravity values that are so diminished, distorted or
incongruent that they are not consistent with normal human urine.
Tainted - Indicates the sample failed a component of the qualitative adulterant screening test.
Threshold - This is the lower limit, cut-off or minimum point where the level detected is considered as
"Positive" in qualitative or semi-quantitative assays. These cutoff levels follow the
recommendations of SAMHSA.
Voucher - Refers to the Chain of Custody Requisition.
DOCUMENT APPROVAL:
Revision History:
Date
Rev. No.
11/14/01
0
2/6/02
1
748959060
William J. Salas BS, MT(ASCP), NM(ASCP) - Laboratory Director
(Original signed document maintained in Master Laboratory Manual)
Change Description:
Initial draft of the document
Added Adulterated and diluted specimens and
oxidizing agents
Eff: 2/6/02
Doc. No. 18.323
Author:
Bill Salas
Bill Salas
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