title: An online field-amplification sample stacking method for the determination of β2-agonists in human urine by CE-ESI/MS.
abstract: Field amplified sample stacking (FASS) was combined with a simple, rapid, sensitive CE-ESI-MS method to achieve the on-line enrichment and simultaneous determination of Clenbuterol (CLE), Salbutamol (SAL), Terbutaline (TER) and Formoterol (FOR). Samples were diluted in deionized water, and electrokinetic injection (10 kV × 50 s) was employed to carry out FASS. With FASS, the four β2-agonists had simultaneously baseline enhancement as much as 319, 332, 297 and 115 fold, respectively. Consequently, satisfactory LODs (S/N=3) of 0.08, 0.1, 0.1 and 0.5 ng/mL for CLE, SAL, TER and FOR were obtained. The separation of the four analytes was performed at 22 kV in ammonium acetate/ammonia (20 mmol/L, pH 9.0), using 7.5 mmol/L acetic acid in isopropanol/water 50/50% (v/v) as sheath liquid. In addition, an excellent linear response was obtained with RSD less than 1.3% for migration times and less than 6.7% for peak areas (n=5). The recoveries of spiked urine samples were in the range of 82.7-101% with RSD lower than 9.8%. The proposed method has been applied to analyze human urine samples successfully.
authors.affiliation: Ministry of Education Key Laboratory of Analysis and Detection for Food Safety, College of Chemistry and Chemical Engineering, Fuzhou University, Fuzhou, Fujian 350108, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: He
authors.forename: Xin
authors.initials: X
authors.lastname: Li
authors.forename: Ping
authors.initials: P
authors.lastname: Tong
authors.forename: Minghua
authors.initials: M
authors.lastname: Lu
authors.forename: Lan
authors.initials: L
authors.lastname: Zhang
authors.forename: Guonan
authors.initials: G
authors.lastname: Chen
mesh_terms: D058666:Adrenergic beta-2 Receptor Agonists / Q000493:pharmacokinetics / Q000652:urine*; D019075:Electrophoresis, Capillary; D004983:Ethanolamines / Q000493:pharmacokinetics / Q000652:urine*; D006801:Humans; D008297:Male; D009862:Online Systems; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
chemical_list: D058666:Adrenergic beta-2 Receptor Agonists; D004983:Ethanolamines