College of Agriculture, Hebei University of Engineering, Handan 056038, China.
J Chromatogr A. 2010 Dec 10;1217(50):7873-7. doi: 10.1016/j.chroma.2010.10.055. Epub 2010 Oct 21.
A simple, sensitive and reliable analytical method was developed for the simultaneous determination of clenbuterol (CLB), salbutamol (SAL) and ractopamine (RAC) in milk by ultra high performance liquid chromatography-positive electrospray ionization tandem mass spectrometry (UHPLC-ESI-MS/MS) with isotope dilution. Samples were directly purified through HLB cartridge. Then the eluate was dried under nitrogen and residues were redissolved in mobile phase. Samples were analyzed by LC-MS/MS on an Acquity UPLC(®) BEH C(18) column with gradient elution. The samples were quantified using clenbuterol-D(9), salbutamol-D(3) and ractopamine-D(6) as internal standards. The proposed method was validated according to the European Commission Decision 2002/657/EC determining specificity, decision limit (CCα), detection capability (CCβ), recovery, precision, linearity, robustness and stability. CCα values were 0.054, 0.006 and 0.008μg/kg for CLB, SAL and RAC, respectively. CCβ values were 0.058, 0.007 and 0.009μg/kg for CLB, SAL and RAC, respectively. The mean recoveries, repeatability (expressed as coefficient of variation, CV(r)), and reproducibility (CV(R)) varied from 95.8 to 106.2%, from 3.60 to 6.44% (CVr), and from 4.77 to 7.53% (CV(R)), respectively. The method is demonstrated to be suitable for the determination of clenbuterol, salbutamol and ractopamine in milk. The total time required for the analysis of one sample, including sample preparation, was about 45min.
建立了一种超高效液相色谱-正电喷雾串联质谱法（UHPLC-ESI-MS/MS），采用同位素稀释法，用于同时测定牛奶中的克伦特罗（CLB）、沙丁胺醇（SAL）和莱克多巴胺（RAC）。样品直接通过 HLB 小柱净化。然后将洗脱液在氮气下干燥，残留物用流动相重新溶解。样品在 Acquity UPLC（®）BEH C（18）柱上进行 LC-MS/MS 分析，采用梯度洗脱。使用克伦特罗-D（9）、沙丁胺醇-D（3）和莱克多巴胺-D（6）作为内标进行定量。该方法按照欧盟委员会 2002/657/EC 号决定进行验证，确定了专属性、决定限（CCα）、检测能力（CCβ）、回收率、精密度、线性、稳健性和稳定性。CLB、SAL 和 RAC 的 CCα 值分别为 0.054、0.006 和 0.008μg/kg。CLB、SAL 和 RAC 的 CCβ 值分别为 0.058、0.007 和 0.009μg/kg。平均回收率、重复性（表示为变异系数，CV（r））和再现性（CV（R））分别为 95.8%106.2%、3.60%6.44%（CVr）和 4.77%~7.53%（CV（R））。该方法适用于牛奶中克伦特罗、沙丁胺醇和莱克多巴胺的测定。包括样品制备在内，分析一个样品所需的总时间约为 45min。
