LC-QTOF-MS as a superior strategy to immunoassay for the comprehensive analysis of synthetic cannabinoids in urine

Abstract

The objective of this study was to compare the performance of an immunoassay screening for synthetic cannabinoids with a newly developed confirmation method using liquid chromatography quadrupole time-of-flight mass spectrometry. The screening included metabolites from JWH-018, JWH-073, and AM-2201. The confirmation included metabolites from AM-2201, JWH-018, JWH-019, JWH-073, JWH-081, JWH-122, JWH-210, JWH-250, JWH-398, MAM-2201, RCS-4, and UR-144. The immunoassay was tested and found to have no cross-reactivity with UR-144 metabolites but considerable cross-reactivity with MAM-2201 and JWH-122 metabolites. Sensitivity and specificity for the immunoassay were evaluated with 87 authentic urine samples and found to be 87% and 82%, respectively. With a cutoff at 2 ng/ml, the confirmation showed 80 positive findings in 38 cases. The most common finding was JWH-122 5-OH-pentyl, followed by JWH-018 5-OH-pentyl. There were 9 findings of UR-144 metabolites and 3 of JWH-073 metabolites. In summary, the immunoassay performed well, presenting both high sensitivity and specificity for the synthetic cannabinoids present in the urine samples tested. The rapid exchange of one cannabinoid for another may pose problems for immunoassays as well as for confirmation methods. However, we consider time-of-flight mass spectrometry to be superior since new metabolites can be quickly included and identified.

Metabolic characterization of (1-(5-fluoropentyl)-1H-indol-3-yl)(4-methyl-1-naphthalenyl)-methanone (MAM-2201) using human liver microsomes and cDNA-overexpressed cytochrome P450 enzymes

“…plasma concentrations ranged from <0.1 to 49 ng/mL, indicating its extensive metabolism [19][20][21][25][26][27]. N-(5-hydroxypentyl)-MAM-2201, N-(4-hydroxyfluoropentyl)-MAM-2201, MAM-2201 pentanoic acid, and dealkyl-MAM-2201 have been identified as the metabolites of MAM-2201 in urine and hair samples from MAM-2201 abusers [27][28][29][30][31][32].…”

High-resolution mass spectrometry in toxicology: current status and future perspectives

“…Kinyua et al presented a similar qualitative screening workflow also based on all-ions MS/MS to allow detection and tentative identification of NPS and their metabolites (Kinyua et al 2015). Finally, Kronstrand and co-workers compared the performance of an immunoassay screening for synthetic cannabinoids with a newly developed confirmation method using QTOF MS and found the MS procedure to be superior since new compounds and their metabolites can be quickly included and hence identified (Kronstrand et al 2014). …”

Bioanalytical methods for the determination of synthetic cannabinoids and metabolites in biological specimens

“…The main challenge of non-targeted LC-HRMS screening methods is to achieve sufficient selectivity to identify low concentrations of SC [19]. Several non-targeted methods using HRMS technique for screening of drugs of abuse including SCs in biological matrices were published [89,94,114,115]. These methods are enabling forensic laboratories to obtain accurate data of MS and MS/MS without pre-selecting substances.…”