Simultaneous quantification of amphetamines and ephedrines in urine by GC/MS using analytical-grade acetic anhydride/pyridine as derivatizing reagents: a suitable approach to reduce costs of routine analyses

Abstract

Neste trabalho foi desenvolvido e validado um método quantitativo para a análise de anfetaminas e efedrinas em urina, utilizando-se anidrido acético e piridina, ambos em grau analítico, como derivatizantes. As amostras foram extraídas por extração em fase sólida (EFS), derivatizadas e em seguida analisadas por CG-EM. O método apresentou ampla faixa linear (25-1000 ng mL-1 com R 2 > 0,99), alta sensibilidade (LODs variando de 0,0140 a 15,33 ng mL-1 e LOQs variando de 0,0466 a 51,10 ng mL-1), bons índices de precisão (CV < 6% para intra-e inter-ensaios) e excelentes índices de recuperação (87-96%) para todos os compostos estudados. Após a validação, o método foi aplicado em análises de amostras reais de urina humana nas quais ao menos um dos analitos em estudo foi identificado previamente. Em todas as amostras, anfetaminas e efedrinas foram facilmente quantificadas mostrando que a associação de anidrido acético e piridina é uma boa opção como agente derivatizante. A GC/MS method for the simultaneous analyses of different amphetamines and ephedrines in urine employing analytical-grade acetic anhydride/pyridine as derivatizing reagents was developed and validated. Solid-phase extraction was performed on the samples, which were then derivatizated and analyzed by GC/MS. The method showed a broad linear dynamic range (25-1000 ng mL-1 with R 2 > 0.99), high sensitivity (LODs of 0.0140 to 15.33 ng mL-1 and LOQs of 0.0466 to 51.10 ng mL-1), good precision (CV < 6% for intra-and inter-assays), and excellent extraction recovery (87 to 96%) for all the compounds studied. After validation, the method was applied in the analyses of real samples of human urine which were previously determined to contain at least one of such drugs. In all the samples, the amphetamines and ephedrines were promptly quantified, showing that the association of acetic anhydride and pyridine can be conveniently employed as a derivatizing agent.

Analytical chemistry in Brazil: healthy and growing

“…GC-MS was employed for the simultaneous determination of amphetamines and ephedrines in urine with an alternative chemical derivatization. 189 In other work, the determination of toluene in urine aiming evaluation of occupational exposure to the solvent was carried out by GC with detection by flame ionization. 190 The number of applications of capillary electrophoresis, including pharmaceutical analysis, has rapidly increased in view of fast separations and higher resolution, also avoiding the use of toxic solvents.…”

Sensing Precursors of Illegal Drugs—Rapid Detection of Acetic Anhydride Vapors at Trace Levels Using Photoionization Detection and Ion Mobility Spectrometry

“…Detection of AA was also reported by using other classical analytical techniques, such as gas or liquid chromatography coupled with mass spectrometry [22]. Moreover, dedicated sensors for real time detection of AA were manufactured; for instance, Nugroho and co-authors reported the development of new nanofibers from cellulose acetate and chitosan used for the detection of AA [23].…”

“…Moreover, dedicated sensors for real time detection of AA were manufactured; for instance, Nugroho and co-authors reported the development of new nanofibers from cellulose acetate and chitosan used for the detection of AA [23]. The obtained results highlighted a fast response (44 s) and decently good sensitivity (10-1000 ppm), with a reported lower limit of detection of 5 ppm [22]. However, these figures of merit are nevertheless poorer than the sensitivity and speed of response of both IMS (<0.1 ppm v ) and PID (low ppb v ) devices which were used during our investigation.…”