Solid-phase microextraction for the determination of cocaine and cocaethylene in human hair by gas chromatography–mass spectrometry

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

“…For cocaine analysis, SPME allows the detection of cocaine analytes at parts per billion (ppb) levels (ng/mL) in variable specimens such as urine, plasma, sweat, saliva and hair (Alvarez et al, 2007;Bermejo et al, 2006;Follador et al, 2004;Yonamine & Saviano, 2006;Yonamine et al, 2003).…”

Development and validation of an analytical method for the simultaneous determination of cocaine and its main metabolite, benzoylecgonine, in human hair by gas chromatography/mass spectrometry

“…Therefore, the chosen extraction conditions were 3 h at 658C, which is a considerably shorter extraction time than in other published methods. 14,15,19,[25][26][27][28][40][41][42] …”

“…9 The analysis of cocaine and metabolites in hair usually begins with the quantitative extraction of the compounds from the matrix, which is the most time-consuming step in hair analysis. This can be achieved by several procedures, such as solvent or buffer extraction, [10][11][12][13][14][15] enzymatic digestion, [16][17][18][19][20] or treatment with hydrochloric acid at different concentrations, [21][22][23][24][25][26][27][28] using different temperatures and extraction time profiles. However, care should be taken in this step, since spontaneous conversion of cocaine into its metabolite benzoylecgonine as an artifact during sample extraction, especially under strong alkaline conditions, has been documented.…”

“…However, care should be taken in this step, since spontaneous conversion of cocaine into its metabolite benzoylecgonine as an artifact during sample extraction, especially under strong alkaline conditions, has been documented. 24,29,30 Several techniques for sample cleanup have been described, such as liquid-liquid extraction, 31,32 solid-phase extraction (SPE), 27,[33][34][35][36][37] solid-phase microextraction, 19,38 or supercritical fluid extraction, 39 followed by either liquid or gas chromatography. This paper describes a new gas chromatography/ mass spectrometry (GC/MS)-based analytical method for the quantitation of cocaine and its main metabolite benzoylecgonine in hair samples after a short 3 h acidic extraction followed by mixed-mode SPE.…”

Desenvolvimento de método de triagem de substâncias psicoativas em amostras de cabelo através de técnicas imunológicas

“…Embora a técnica de extração por SPE seja amplamente utilizada, técnicas miniaturizadas como a LPME e a SPME são a tendência atual, como já mencionado (BACIU et al, 2015). A utilização da técnica de SPME para extração de cocaína e seus produtos de biotransformação em cabelo já foi reportada com sucesso por alguns autores (TOLEDO et al, 2003;POON et al, 2014;MEROLO et al, 2010;BERMEJO et al, 2006). Entretanto o baixo custo/benefício e os efeitos de carryover relacionados a fibra representam um ponto fraco para a técnica (XIONG et al, 2010), havendo assim um apelo para que outras técnicas miniaturizadas sejam exploradas como a LPME.…”