Determination of five abused drugs in nitrite-adulterated urine by immunoassays and gas chromatography-mass spectrometry

49Citations
Citations of this article
27Readers
Mendeley users who have this article in their library.

This article is free to access.

Abstract

The adulteration of urine specimens with nitrite ion has seen shown to mask the gas chromatography-mass spectrometry (GC-MS) confirmation testing of marijuana use. This study was designed to further investigate the effect of nitrite adulteration on the detection of five commonly abused drugs by immunoassay screening and GC-MS analysis. The drugs tested are cocaine metabolite (benzoylecgonine), morphine, 11-nor-Δ9-tetrahydrocannabinol-9- carboxylic acid (THCCOOH), amphetamine, and phencyclidine. The immunoassays evaluated included the instrument-based Abuscreen ONLINE assays, the on-site Abuscreen ONTRAK assays, and the one-step ONTRAK TESTCUP-5 assay. Multianalyte standards containing various levels of drugs were used to test the influence of both potassium and sodium nitrite. In the ONLINE immunoassays, the presence of up to 1.0M nitrite in the multianalyte standards had no significant effect for benzoylecgonine, morphine, and phencyclidine assays. With a high concentration of nitrite, ONLINE became more sensitive for amphetamine (detected more drug than what was expected) and less sensitive for THCCOOH (detected less drug than what was expected). No effects of nitrite were observed on the results of the Abuscreen ONTRAK assays. Similarly, no effects were observed on the absolute qualitative results of the TESTCUP-5 when testing the nitrite-adulterated standards. However, the produced intensities of the signals that indicate the negative test results were slightly lowered in the THC and phencyclidine assays. The presence of 1.0M of nitrite did not show dramatic interference with the GC- MS analysis of benzoylecgonine, morphine, amphetamine, and phencyclidine. In contrast, nitrite ion significantly interfered with the detection of THCCOOH by GC-MS. The presence of O.03M of nitrite ion resulted in significant loss in the recovery of THCCOOH and its internal standard by GC-MS. The problem of nitrite adulteration could be alleviated by sodium bisulfite treatment even when the specimens were spiked with 1.0M of nitrite ion. Although bisulfite treatment decomposed all nitrite ions in the sample to recover the remaining THCCOOH by GC-MS, the net recovery of THCCOOH depended on urinary pH and time and conditions of sample storage. The presence of nitrite concentrations that might arise from all possible natural sources, including microorganisms, pathological conditions, and medications, did not interfere with the GC-MS analysis of THCCOOH.

References Powered by Scopus

Drugs-of-abuse testing in urine: Statistical approach and experimental comparison of immunochemical and chromatographic techniques

92Citations
N/AReaders
Get full text

Interference of common household chemicals in immunoassay methods for drugs of abuse

89Citations
N/AReaders
Get full text

Nitrite adulteration of workplace urine drug-testing specimens I. Sources and associated concentrations of nitrite in urine and distinction between natural sources and adulteration

51Citations
N/AReaders
Get full text

Cited by Powered by Scopus

Is this urine really negative? A systematic review of tampering methods in urine drug screening and testing

114Citations
N/AReaders
Get full text

Oral fluid testing for drugs of abuse: Positive prevalence rates by intercept™ immunoassay screening and GC-MS-MS confirmation and suggested cutoff concentrations

98Citations
N/AReaders
Get full text

Methods for the analysis of cannabinoids in biological materials: A review

94Citations
N/AReaders
Get full text

Register to see more suggestions

Mendeley helps you to discover research relevant for your work.

Already have an account?

Cite

CITATION STYLE

APA

Tsai, S. C. J., ElSohly, M. A., Dubrovsky, T., Twarowska, B., Towt, J., & Salamone, S. J. (1998). Determination of five abused drugs in nitrite-adulterated urine by immunoassays and gas chromatography-mass spectrometry. Journal of Analytical Toxicology, 22(6), 474–480. https://doi.org/10.1093/jat/22.6.474

Readers' Seniority

Tooltip

PhD / Post grad / Masters / Doc 11

79%

Researcher 2

14%

Professor / Associate Prof. 1

7%

Readers' Discipline

Tooltip

Pharmacology, Toxicology and Pharmaceut... 5

38%

Chemistry 3

23%

Medicine and Dentistry 3

23%

Biochemistry, Genetics and Molecular Bi... 2

15%

Save time finding and organizing research with Mendeley

Sign up for free