饲料级硫酸铜中二英类多氯联苯的污染特征及其来源研究

近年来，持久性有机污染物（POPs）对人体和环境带来的危害在世界范围内引起了广泛关注.饲料添加剂已成为畜禽动物养殖过程中必不可少的原料，为探明典型动物饲料添加剂饲料级硫酸铜（CuSO₄）中POPs的来源，本研究分析了饲料级CuSO₄、铜盐产品、蚀刻废液（包括酸性蚀刻废液、碱性蚀刻废液及微蚀废液）、蚀刻液（包括盐酸（HCl）和氧化剂）、硫酸（H₂SO₄）共计79个样品中二英类多氯联苯（DL-PCBs）的污染特征.结果发现，饲料级CuSO₄和铜盐产品中DL-PCBs均以PCB-77、PCB-169和PCB-126为主要检出单体，与其生产原料酸性蚀刻废液中具有完全一致的指纹分布特征，表明其来源的一致性；对于蚀刻液，DL-PCBs仅在工业HCl中有不同程度检出，然而指纹特征（单体组成以PCB-118、PCB-77和PCB-126为主）与其他样品中有所区别.通过主成分分析（PCA）进一步确认表明，工业HCl是蚀刻废液中DL-PCBs的一个重要来源，但亦可能存在其他未知来源.相关研究为去除和控制微量元素饲料添加剂尤其是铜盐产品中DL-PCBs提供了重要的科学依据.

Characteristics and source of dioxin-like PCBs in the feed grade cupric sulfates

In recent years, the adverse effect of persistent organic pollutants (POPs) on human and environment has raised public concern worldwide. Feed additive has become an indispensable raw material in the process of livestock and poultry breeding. In order to identify the sources of POPs in the feed grade copper sulfate (CuSO₄), an typical animal feed additive,we investigated the contamination characteristics of dioxin-like polychlorinated biphenyls (DL-PCBs) in totally 79 samples including feed grade CuSO₄,copper salts, spent etching solutions (acid, alkaline and microetch solutions), etchants (HCl and oxidant) and H₂SO₄. PCB-77, PCB-169 and PCB-126 were the dominant congeners in the feed grade CuSO₄ and copper salts, of which the distribution pattern was consistent with those in the spent acid etching solution, suggesting the same source of DL-PCBs in these matrices. In the etchants,DL-PCBs were only detected in the industrial HCl, and the distribution pattern (dominated by PCB-118,PCB-77 and PCB-126) was slightly different from those in the downstream products. Combining the results from principal component analysis (PCA), the source of DL-PCBs in the spent acid etching solution was closely related to the use of industrial HCl, whereas, there might be some unknown sources that need further identification. This study provided important scientific evidences for DL-PCBs restriction in feed additives,especially in feed grade copper salts.