Table 3.

Immunoassay interference during the detection of synthetic cannabinoids.

Compound/Mix	Analyte concentration (μg/L)	Immunoassay detected concentration (μg/L)
Methanol	72	0.0
Buprenorphine, norbuprenorphine	1000	7.3
Cocaine, benzoylecgonine, norcocaine, nor-benzoylecgonine	1000	2.4
Ecgonine ethyl ester, ecgonine methyl ester, anhydroecgonine methyl ester, ecgonine	1000	1.8
Cocaethylene, norcocaethylene	1000	1.7
m-OH-cocaine, p-OH-cocaine, m-OH-benzoylecgonine, p-OH-benzoylecgonine	1000	1.5
Morphine, normorphine, M3G, M6G	1000	1.9
Codeine, norcodeine, 6-acetylmorphine, 6-acetylcodeine	1000	3.0
Hydrocodone, hydromorphone, oxycodone	1000	0.9
Noroxycodone, oxymorphone, noroxymorphone	1000	1.0
Propoxyphene, 3,4-methylenedioxyphenyl-2-butanamine (BDB), N-methyl BDB	1000	2.2
R-cath, EAMP, 2-CB (4-bromo-2,5-dimethoxiphenethylamine)	1000	2.2
Diazepam, lorazepam, oxazepam, alprazolam	1000	2.2
Imipramine, clomipramine, fluoxetine, norfluoxetine	1000	1.2
Paroxetine, 7-aminoclonazepam, 7-aminoflunitrazepam, 7-aminonitrazepam	1000	3.3
Clonidine, ibuprofen, pentazocine, caffeine	1000	0.7
Diphenhydramine, chlorpheniramine, brompheniramine	1000	1.9
Salicylic acid, acetaminophen, ibuprofen, caffeine	1000	0.4
Bromazepam, clonazepam, flurazepam	1000	1.4
Nitrazepam, flunitrazepam, temazepam, nordiazepam	1000	2.7
Nicotine, cotinine, OH-cotinine, norcotinine	1000	2.1
Methadone, 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP)	1000	2.5
Paramethoxyamphetamine, paramethoxymetamphetamine	1000	0.4
Amphetamine (AMP), Methamphetamine (MAMP), MDMA, MDA, MDEA, HMMA, HMA, OH-AMP, OH-MAMP	1000	1.2
Ephedrine, pseudoephedrine	1000	2.2
Ketamine, dextromethorphan, phentermine	1000	2.4
Cannabigerol	100	2.2
THC, 11-OH-THC, THCOOH, CBD, CBN	1000	2.7
NaCl	40a	−2.6
Ascorbic acid	4a	−0.1
Urine pH > 8 (NaOH)	–	1. 0
Urine pH < 4 (acetic acid)	–	−1.0

^ag/L.