【摘要】 建立了不同鱼贝类肌肉组织中以氘代同位素为内标测定β-雌二醇残留量的气相色谱/质谱(GC/MS)方法。样品中加入内标β-雌二醇-D2和乙酸钠缓冲溶液匀质后,用乙腈超声提取,经过正己烷脱脂,C18固相萃取柱净化和柱前三甲基硅烷化后,进行GC/MS分析。根据β-雌二醇和内标衍生物保留时间、主要特征离子及其相对丰度和平均质谱图定性;选择离子监测(SIM)模式下,根据β-雌二醇和内标衍生物定量离子质量色谱图的峰面积比值,内标标准曲线法定量。实验结果表明,在0.005~0.25mg/L范围内,衍生物定量离子峰面积比值与β-雌二醇浓度呈现良好线性关系,相关系数为0.9995;方法定量检出限为0.2μg/kg。当添加水平为0.2~5.0μg/kg时,回收率为68.5%~100.1%,相对标准偏差为4.8%~10.1%。通过对市场上7种鱼贝类的检测,进一步证明该法可实现对样品进行灵敏、准确的定性定量分析。更多还原

【Abstract】 Using deuterated internal standard, a gas chromatography-mass spectrometric method (GC-MS) was developed for the identification and quantitative determination of β-estradiol residues in the muscle tissues of various fishes/shellfishes. Homogenized tissue samples added with β-estradiol-D2 and acetate buffer (pH 5.2) were extracted by acetonitrile under ultrasonication. Clean-up was carried out with hexane, followed by C18-solid phase extraction (SPE).To enhance detection sensitivity, derivatization was achieved prior to GC-MS analysis with N-methyl-N-(trimethylsilyl)-trifluoroacetamide/iodotrimethylsilane/dithioerythritol (MSTFA-TMIS-DTE).Quantitation using isotope-labelled internal standard was based on the ratio of peak area of β-estradiol derivative to peak area of internal standard derivative in the selected ion monitoring (SIM) mode with electron impact (EI) source. The linearity ranged from 0.005 to 0.25 mg/L.The limit of quantitation (LOQ) was 0.2 μg/kg. At 0.2, 1.0, 5.0 μg/kg spiked levels, the mean recoveries were 68.5%-100.1%, and the relative standard deviations were 4.8%-10.1%.The application of this method was further demonstrated by analyzing various real samples from local markets.更多还原