Screening of Organohalogenated Toxicants in Breast Milk via GCxGC/TOF MS

人类母乳中环境有毒物质的存在是一个重要的问题，因为这些化学物质可能对母乳喂养的婴儿的健康产生影响。亲脂性毒物主要集中在高脂肪母乳中，它们包括几种不同类别的合成有机污染物，如多氯联苯（PCBs）、多氯二苯并对二恶英（pcdd）、多氯二苯并呋喃（pcdf）、多溴二苯醚（PBDEs）和持久性杀虫剂。母乳喂养的婴儿体内这些有毒物质的负荷比成人高一个数量级以上，成年人体内有毒物质水平的升高与生殖、行为和中枢神经系统的几种疾病有关。环境科学家不断努力测量母乳中的有毒物质，这是确定这些化学物质对婴儿健康的真正影响的一个重要因素。有必要制定新的分析性筛选战略，以监测已知环境污染物的水平并查明

The presence of environmental toxicants in human breast milk is an important concern because of the potential health effects of these chemicals to the breast-fed infant. Lipophilic toxicants are preferentially concentrated in high-fat breast milk, and they include several different classes of synthetic organic pollutants such as polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), polybrominated diphenylethers (PBDEs) and persistent pesticides. The body burden of these toxicants in breast-fed infants is more than an order of magnitude higher than it is in adults, and elevated levels in adults have been linked to several disorders of the reproductive, behavioral, and central nervous systems. The continued efforts of environmental scientists to measure toxicants in breast milk are an important factor in the determination of the true contribution of these chemicals to the health of the infant population. There is a need to develop new analytical screening strategies that will monitor the levels of known environmental pollutants as well as identify additional toxicants in breast milk. Current screening methods employ sample extraction protocols that are time-consuming, and the analysis of samples is limited to the list of known toxicants and therefore not capable of detecting new or unknown contaminants. This project is intended to develop an improved method based on the combined emerging technologies of stir bar sorptive extraction (SBSE) and comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry (GCxGC/TOF MS). The specific aims are to: (1) develop a high-throughput sample preparation protocol based on the stir-bar sorptive extraction (SBSE) technique; (2) develop a high-performance sample analysis protocol based on the emerging technology of comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry (GCxGC/TOF MS). The key advantages of GCxGC/TOF MS are enhanced resolution power, analytical throughput and sensitivity over conventional GC; and (3) Validate the new method through a pilot study that will test the overall selectivity, sensitivity and analytical throughput of the GCxGC/TOF MS method when compared to the current state-of-the-art.