Because low levels of nitrite may be present in human urine due to the reasons listed above,
HHS set a cutoff level of 500 mcg/mL for adulteration and 200 mcg/mL for invalid results.
These concentrations are well above levels seen in human urine. Therefore, these reasons
do not explain a nitrite adulterated result.
Chromium (VI)
is a strong oxidizing agent that has been identified in various commercial
adulterant products. The most common forms of the element chromium are chromium (0),
chromium (III), and chromium (VI). All have industrial uses. Both chromium (III) and chromium
(VI) are used for chrome plating, dyes and pigments, leather tanning, and wood preserving.
Chromium (III) is an essential nutrient and is always present in humans. Chromium (VI) is toxic
and has been shown to be a human carcinogen. HHS set an initial test cutoff level of 50
mcg/mL for chromium (VI). Because the presence of chromium (VI) in a urine specimen is
indicative of adulteration, laboratories report a specimen as adulterated when chromium (VI) is
present at any concentration at or above the confirmatory test limit of quantitation (LOQ).
Surfactants
, including ordinary detergents, have been used to adulterate urine specimens.
Surfactants have a particular molecular structure made up of a hydrophilic and a hydrophobic
component. They greatly reduce the surface tension of water when used in very low
concentrations. Foaming agents, emulsifiers, and dispersants are surfactants which suspend
respectively, a gas, an immiscible liquid, or a solid in water or some other liquid. Surfactants
tend to clump together when in solution, forming a surface between the fluid and air, with their
hydrophobic components in the air and their hydrophilic components in the fluid. Often,
surfactants will form "bubbles" within the fluid: a small sphere of hydrophobic “heads”
surrounding a pocket of air containing the hydrophilic “tails.” They can also form bubbles in air
(i.e., two nested spheres of surfactant with a thin layer of water between them, surrounding a
pocket of air) and can form “antibubbles” in fluid (i.e., a layer of air surrounding a pocket of
water). HHS set an initial test cutoff level of 100 mcg/mL dodecylbenzene sulfonate equivalents.
Laboratories report a specimen as adulterated when a surfactant is verified as present at or
above a concentration equivalent to 100 mcg/mL dodecylbenzene sulfonate using a
confirmatory test.
Halogens
are the four elements fluorine, chlorine, bromine, and iodine. Halogen compounds
have been used as oxidizing adulterants. The term “halogen” (from the Greek hals, "salt," and
gennan, "to form or generate") was given to these elements because they are salt formers.
None of the halogens can be found in nature in their elemental form. They are found as salts of
the halide ions (F-, Cl-, Br-, and I-). Fluoride ions are found in minerals. Chloride ions are
found in rock salt (NaCl), the oceans, and in lakes that have a high salt content. Both bromide
and iodide ions are found at low concentrations in the oceans, as well as in brine wells. The
assays used by certified laboratories identify halogen compounds that act as oxidants. These
do not include the halogen salts (e.g., NaCl, KCl, NaI) which may be present in a urine
specimen. An oxidative halogen present at any concentration at or above the confirmatory test
LOQ is evidence of adulteration.
Glutaraldehyde
is a clear, colorless liquid with a distinctive pungent odor sometimes compared
to rotten apples. One of the first effective commercial adulterants was found to contain
glutaraldehyde. Glutaraldehyde is used as a sterilizing agent and disinfectant, leather tanning
agent, tissue fixative, embalming fluid, resin or dye intermediate, and cross-linking agent. It is
also used in X-ray film processing, in the preparation of dental materials, and surgical grafts.
Glutaraldehyde reacts quickly with body tissues and is rapidly excreted. The most common
effect of overexposure to glutaraldehyde is irritation of the eyes, nose, throat, and skin. It can
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