Analysis of cocaine and benzoylecgonine in urine by using multisyringe flow injection analysis‐gas chromatography‐mass spectrometry system

Abstract

In this paper, a method was described to determine cocaine (COC) and benzoylecgonine (BZE) in human urine samples by GC-MS detection. The extraction of analytes from urine samples was achieved in an Oasis hydrophilic-lipophilic balance column (20 mmx3.9 mm id, dp=25 microm; Waters, USA), incorporated in a multisyringe flow injection system, used for the sample treatment. Finally, to improve the volatility of the BZE, an in-line derivatization reaction with N,O-bis (trimethylsilyl) trifluoroacetamide with 1% trimethylchlorosilane was made microwave-assisted in order to reduce the reaction time. The results showed that the proposed method is a good alternative for the analysis of COC and BZE in urine samples because it offers advantages compared with those described in the literature, which include simplicity in the sample treatment, the sensitivity and selectivity necessary to determine the analytes of interest at low levels in the urine and high sample throughput.

Development and validation of a gas chromatography/ion trap-mass spectrometry method for simultaneous quantification of cocaine and its metabolites benzoylecgonine and norcocaine: Application to the study of cocaine metabolism in human primary cultured renal cells

“…Several GC/MS methods have been described in the literature for the determination of cocaine and its metabolites in biological fluids (blood, urine and sweat) [21][22][23][24]. However, to the best of our knowledge, the quantification of these compounds in a cellular matrix has not been investigated yet.…”

Optimization and validation of simultaneous analyses of ecgonine, cocaine, and seven metabolites in human urine by gas chromatography–mass spectrometry using a one‐step solid‐phase extraction

“…19 This extraction procedure allows reaching LLOQs which are significantly lower than previously published literature, yet using two ion-exchange cartridges and two extraction processes with greater volumes, resulting in a much more expensive sample pre-treatment (Table 2). [13][14][15][16][17][18][19]26,27,[29][30][31][32][33][34][35][36][37][38][39] The present method is the first to apply one-step SPE and GC-MS to urine samples to identify and quantify ECG, EME, BE, m-OHBE, COC, CE, NC, NCE, and NBE, requiring only 500 μL of sample and reaching lower LLOQs with a simple and fast process, making it an excellent option to apply routinely in different toxicology laboratories.…”

“…According to our results, a one-step SPE method can be considered a powerful technique, revealing a fast and efficient extraction of the target analytes with a lower sample and solvent consumption ( Table 2). [13][14][15][16][17][18][19]26,27,[29][30][31][32][33][34][35][36][37][38][39]…”

Chromatographic Methodologies for Analysis of Cocaine and Its Metabolites in Biological Matrices

“…In addition, many studies employ a catalyst like trimethylchlorosilane (TMCS) with BSTFA (Brunet et al, 2008;Brunetto et al, 2010;Cone et al, 1994a;Kintz & Mangin, 1995;Romolo et al, 2003), or less commonly t-butyldimethylchlorosilane (TBDMCS) with the silylating agent N-methyl-N-t-butyldimethylsilyltrifluoroacetamide (MTBSTFA) (Lowe et al, 2006), to improve the silylating potential of the derivatizing agents (Segura et al, 1998).…”

“…The shorter time of preparation and the less amount of solvents required for analysis are the main advantages of silylation over acylation (Segura et al, 1998 Urine Cocaine, EME PFPA/PFPOH 12.5 -50 ng/mL (Saito et al, 2007) Sweat Cocaine, BE, EME, EDME BSTFA/TMCS 2.5 ng/patch (Brunet et al, 2008) Urine Cocaine, BE BSTFA/TMCS 3 -10 ng/mL (Brunetto et al, 2010) Adipose tissue Cocaine, BE, EME, CE BSTFA 5 -20 ng/g (Colucci et al, 2010) Hair Cocaine, CE MSTFA 0.08 -0.09 ng/mg (Merola et al, 2010) BE -benzoylecgonine; BSTFA -N,O-bis(trimethylsilyl)trifluoroacetamide; CE -cocaethylene; EDME -ecgonidine methyl ester; EEE -ecgonine ethyl ester; EME -ecgonine methyl ester; HFBA -heptafluorobutyric anhydride; HFIP -1,1,1,3,3,3-hexafluoroisopropanol; MSTFA -N-methyl-Ntrimethylsilyltrifluoroacetamide; MTBSTFA -N-methyl-N-t-butyldimethylsilyltrifluoroacetamide; PFPA -pentafluoropropionic anhydride; PFPOH -2,2,3,3,3-pentafluoro-1-propanol; TBDMCS -t-butyldimethylchlorosilane; TMCS -trimethylchlorosilane. Table 3.…”