title: Clean-up, detection and determination of salbutamol in human urine and serum.
abstract: Salbutamol ¿2-(tert-butylamino)-1-[4-hydroxy-3- (hydroxymethyl)phenyl]ethanol¿, also known as albuterol, is clinically the most widely used beta 2-adrenoceptor agonist in the treatment of bronchial asthma. During this study, we evaluated liquid-liquid extraction (LLE) and solid-phase extraction (SPE) in order to develop a reliable extraction method followed by analysis using liquid chromatography and gas chromatography. An assay is described which involves SPE as the clean-up method followed by gas chromatography-mass spectrometry to determine salbutamol levels in human serum after oral administration. The SPE method requires the use of a hyper-cross-linked styrene-divinylbenzene bonded phase (ENV+) without involving any sample pre-treatment to obtain 60-65% recoveries for salbutamol and terbutaline as the internal standard. Distilled water and 1% trifluoroacetic acid in methanol were found to be the most suitable washing solvent and eluting solvent, respectively. A detection limit of 2 ng mL-1 was achieved by derivatization with N-methyl-N-trimethylsilyltrifluoroacetamide to form trimethylsilyl (TMS)-salbutamol (m/z 369) and TMS-terbutaline (m/z 356). The relationship between the ratio of the peak area of salbutamol to that of the internal standard and concentration was linear for the range tested (2-200 ng mL-1) and the correlation of coefficient was 0.9999 with a y-intercept not significantly different from zero. The inter-day relative standard deviation (RSD) was < 10% for all three concentrations. The intra-day RSD was 14% for 2 ng mL-1. This assay was then successfully applied to human serum samples obtained from clinical trials after oral administration of salbutamol.
authors.affiliation: School of Chemical Sciences, Doping Control Center, Universiti Sains Malaysia, Minden, Penang, Malaysia.
authors.forename: M I
authors.initials: MI
authors.lastname: Saleh
authors.forename: Y M
authors.initials: YM
authors.lastname: Koh
authors.forename: S C
authors.initials: SC
authors.lastname: Tan
authors.forename: A L
authors.initials: AL
authors.lastname: Aishah
mesh_terms: D000328:Adult; D000420:Albuterol / Q000032:analysis* / Q000097:blood / Q000652:urine; D001993:Bronchodilator Agents / Q000032:analysis* / Q000097:blood / Q000652:urine; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D008297:Male; D015203:Reproducibility of Results
chemical_list: D001993:Bronchodilator Agents; D000420:Albuterol