Quantitative detection of salmeterol after inhalation in equine urine by liquid chromatography/tandem mass spectrometry

Abstract

A sensitive, accurate and precise liquid chromatography/tandem mass spectrometry (LC/MS(2)) method was developed for the quantification of salmeterol in the urine of horses. The method consists of a liquid-liquid extraction with tert-butylmethyl ether and isopropanol at pH 12 after enzymatic hydrolysis. The extracts are analysed using an LC/MS system equipped with an electrospray ionisation (ESI) probe. Method validation showed excellent linearity, specificity, accuracy, precision and intra-laboratory repeatability and reproducibility. The limit of quantitative detection was 0.25 ng/mL and the limit of detection was 0.125 ng/mL. The excretion profile was determined after administration of 500 microg salmeterol (Serevent) to four standard-bred mares via a metered dose inhaler (MDI) with an Equinehaler adapter. Salmeterol was detected from 1 h until 12 h post-administration. Maximum urinary concentrations varied between 2.3 and 14.9 ng/mL.

Mass Spectrometry in Doping Control Analysis

“…[128]. The improvements in interfacing liquid chromatography to mass spectrometry by ESI or APCI and the superior suitability of LC over GC regarding chromatographic separation of analytes with structures related to common β 2 -agonists has led to a considerable number of applications employing LC-MS(/MS) for doping control, food control or forensic purposes [129][130][131][132][133][134][135][136]. Nevertheless, several assays utilizing one or more derivatization steps followed by GC-MS(/MS) also allow a sensitive and selective detection of prohibited compounds in respective matrices [137][138][139][140][141][142][143][144].…”

Minimizing matrix effects in the development of a method for the determination of salmeterol in human plasma by LC/MS/MS at low pg/mL concentration levels

“…This method uses liquid-liquid extraction (LLE) for sample preparation and was used for analysis of high concentration samples up to 14 ng/mL. Another LLE-based LC/MS/MS method for analysis of equine urine after inhaled administration of salmeterol was described by Van Eenoo et al with the LLOQ of 0.25 ng/mL [13]. A method based on LC with fluorescence detection for analysis of salmeterol in rat and dog plasma was described by Colthup et al [14,15].…”

Development of a sensitive method for simultaneous determination of fluticasone propionate and salmeterol in plasma samples by liquid chromatography‐tandem mass spectrometry

“…Several methods for determination of fluticasone propionate and salmeterol have been published so far, with applications in pharmacokinetics (PK) or doping control (Laugher et al, 1999;Krishnaswami et al, 2000;Zhou et al, 2003;Van Eenoo et al, 2002;Lehner et al, 2004;Čapka and Carter, 2007;Carter and Čapka et al, 2008;Garcia et al, 2011). Most analytical methods presented in the literature deal separately with fluticasone propionate (Laugher et al, 1999;Krishnaswami et al, 2000) and salmeterol or groups of β-adrenergic receptor agonists (Van Eenoo et al, 2002;Lehner et al, 2004;Čapka and Carter, 2007;Garcia et al, 2011). For PK profiling of pharmaceutical formulations containing both active moieties, this separate approach is time-consuming; furthermore, previous methods often lack the sensitivity to detect pharmacologically relevant plasma concentrations, especially in the case of salmeterol.…”