Quantification of ephedrines in urine by column-switching high-performance liquid chromatography

Development and validation of an LC–MS/MS method for the quantification of ephedrines in urine

“…For NPEP a threshold of 5 g/mL and for EP and MEP a threshold of 10 g/mL is applied. In anti-doping analysis ephedrines used to be quantified in urine by GC-NPD, GC-MS or HPLC-UV after preconcentrating the sample by liquid-liquid extraction (LLE) [3][4][5] or after an online clean-up [6]. The sensitivity of liquid chromatography coupled to mass spectrometry (LC-MS) and the compatibility of the system with the aqueous matrix of urine has allowed quantitative analysis of ephedrines without preconcentration step by direct injection [7,8].…”

Investigação da presença de efedrinas em Ephedra tweediana Fisch & C.A. Meyer e em E. triandra Tul. (Ephedraceae) coletadas em Porto Alegre/RS

“…Muitos métodos têm sido relatados na literatura científi ca para detecção de efedrina em extratos vegetais, suplementos alimentares e amostras biológicas, utilizando as técnicas de cromatografi a à líquido de alta efi ciência (JP XIII, 1996;Gurley et al, 1998;Gmeiner et al, 2002), cromatografi a à gas (Garcia et al, 2005;Marchei et al, 2006), eletroforese capilar (MateusAvois et al, 2003) e espectrometria de massas (Gay et al, 2001;Spyridaki et al, 2001;Tseng et al, 2003). Entretanto, a maioria destes métodos está relacionada à análise de efedrinas em urina ou suplementos alimentares, reportando extensas fases de preparação da amostra e não permitindo efi ciente separação de EF e PEF (Spyridaki et al, 2001;Tseng et al, 2003), o que é de extrema importância em se tratando de análises toxicológicas, dopagem e monitoramento terapêutico, uma vez que ambos isômeros apresentam diferentes atividades farmacológicas e ações sobre o SNC, considerando que metodologias envolvendo detector de massas são preferidas em alto grau para identifi cação de substâncias contidas em produtos de origem desconhecida, esta foi à metodologia escolhida para a realização deste trabalho.…”

Separation Methods for Toxic Components in Traditional Chinese Medicines

“…However, they are classified as prohibited substances according to the International Olympic Committee (IOC)'s list of prohibited classes of substances, due to their potency to stimulate the central nervous system 85 and the concentration limits of five ephedrine derivatives in urine have been established. 86 Furthermore, high doses of ephedrines are also responsible for some incidents of acute hepatitis and nephrolithiasis.…”

“…It successfully resolved the problem of time-consuming sample clean-up step and made the automation possible. 85 In order to further enhance the sensitivity compared with that of a UV detector, Aymard presented a specific HPLC analysis method with fluorometric detection for quantification of ephedrine and norephedrine in human plasma after liquid-liquid extraction and derivatization with 9-fluorenylmethyl chloroformate. 96 The satisfactory detection limits of 2 ng/mL for ephedrine and 5 ng/mL for norephedrine were obtained.…”