Letcher R J, Norstrom R J, Bergman A
Department of Chemistry, Carleton University, Ottawa, Ontario, Canada.
Anal Chem. 1995 Nov 15;67(22):4155-63. doi: 10.1021/ac00118a019.
A simple column chromatography method was developed for separation and cleanup in the determination of chlorinated hydrocarbon contaminants and their methyl sulfone (MeSO2-) metabolites in biological tissues. The method was validated for determination of 11 polychlorinated biphenyls (PCBs), 15 tetra- to heptachloro 3- and 4-MeSO2-PCBs, 3-MeSO2-DDE, and tris(4-chlorophenyl)-methanol spiked to herring gull egg, smelt, and polar bear liver and adipose tissue using gas chromatography with electron-capture detection (GC-ECD). The overall mean recovery relative to the internal standard was 103% +/- 8%, independent of analyte, substrate type, and lipid extract weights up to approximately 0.7 g. Precision of replicate analyses of individual congeners was good. There were no significant residual biogenic or xenobiotic interferences in the aryl methyl sulfone fraction of any substrate. Sensitivity and linearity of molar response of MeSO2-PCBs and MeSO2-DDE was tested for ECD and electron-capture negative ion mass spectrometry monitoring the total ion current (TIC) and the molecular ion (SIM). The mean practical quantitation limit among MeSO2-PCBs and 3-MeSO2-DDE was lowest for SIM (2.1 +/- 0.9 pg) and similar for ECD and TIC (24.2 +/- 4.6 and 44.4 +/- 17.1 pg, respectively). Response factors were linear above the practical quantitation limit to at least the nanogram level for all three techniques. In spite of superior sensitivity, there was more inherent variability in the response factors for SIM (approximately 18%-56% CV) than for ECD (approximately 7%-12% CV) or TIC (approximately 11%-18% CV); therefore, ECD or TIC is recommended for quantitative analysis.
开发了一种简单的柱色谱法，用于生物组织中氯代烃污染物及其甲砜（MeSO2-）代谢物的分离和净化。该方法通过气相色谱-电子捕获检测（GC-ECD）对添加到银鸥蛋、胡瓜鱼以及北极熊肝脏和脂肪组织中的11种多氯联苯（PCBs）、15种四至七氯3-和4-MeSO2-PCBs、3-MeSO2-DDE以及三（4-氯苯基）-甲醇进行测定，从而得到验证。相对于内标物，总体平均回收率为103%±8%，与分析物、底物类型以及高达约0.7 g的脂质提取物重量无关。各个同系物重复分析的精密度良好。任何底物的芳基甲砜部分均不存在显著的残留生物源或外源性干扰。针对ECD以及监测总离子流（TIC）和分子离子（SIM）的电子捕获负离子质谱，测试了MeSO2-PCBs和MeSO2-DDE的摩尔响应灵敏度和线性。MeSO2-PCBs和3-MeSO2-DDE的平均实际定量限在SIM下最低（2.1±0.9 pg），ECD和TIC下相近（分别为24.2±4.6和44.4±17.1 pg）。对于所有三种技术，响应因子在实际定量限以上至少到纳克水平呈线性。尽管SIM灵敏度更高，但其响应因子的固有变异性（约18%-56% CV）大于ECD（约7%-12% CV）或TIC（约11%-18% CV）；因此，建议采用ECD或TIC进行定量分析。
