Zhao Zunyang, Fang Yuan, Love Nancy G, Knowlton Katharine F
Department of Dairy Science, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA.
Chemosphere. 2009 Jan;74(4):551-5. doi: 10.1016/j.chemosphere.2008.09.055. Epub 2008 Nov 6.
Wastes generated by animal agriculture have complex matrices and present a significant challenge for achieving accurate measurements of estrogens. The objective of this study was to compare two different extraction methods and two different biochemical and biological estrogen assays on two dairy manure matrices. The two extraction methods studied in this research were a two-step base-toluene extraction and a one-step cyclohexane extraction. The two assays assessed were an enzyme-linked immunosorbent assay (ELISA) and a yeast estrogen screen (YES) bioassay. Estrogenic activity was measured directly as 17beta-estradiol (E2) through the ELISA method or as E2 equivalents (E2-eq) through the YES bioassay. Both extraction methods yielded reasonable recoveries from distilled water in the absence of matrix interferences. In manure samples, ELISA resulted in recoveries slightly higher than 100% in two types of dairy manures, but YES recoveries varied. The YES bioassay detected much higher estrogenic activities in dairy manure compared to the E2 concentrations measured by ELISA. The base-solvent extraction yielded higher E2 concentrations in dairy manure compared to the one-step cyclohexane extraction. These results suggest that manure matrices vary sufficiently that extraction methods must be optimized for specific assays utilized to quantify estrogens in manures.
畜牧养殖产生的废弃物具有复杂的基质，这给准确测定雌激素带来了重大挑战。本研究的目的是比较两种不同的提取方法以及两种不同的生化和生物雌激素检测方法，用于检测两种奶牛粪便基质。本研究中所研究的两种提取方法分别是两步碱 - 甲苯提取法和一步环己烷提取法。所评估的两种检测方法分别是酶联免疫吸附测定法（ELISA）和酵母雌激素筛选（YES）生物测定法。通过ELISA方法直接将雌激素活性测定为17β - 雌二醇（E2），或者通过YES生物测定法测定为E2当量（E2 - eq）。在没有基质干扰的情况下，两种提取方法从蒸馏水中都获得了合理的回收率。在粪便样本中，ELISA在两种类型的奶牛粪便中的回收率略高于100%，但YES的回收率各不相同。与ELISA测定的E2浓度相比，YES生物测定法检测到奶牛粪便中的雌激素活性要高得多。与一步环己烷提取法相比，碱 - 溶剂提取法在奶牛粪便中产生的E2浓度更高。这些结果表明，粪便基质差异足够大，以至于必须针对用于量化粪便中雌激素的特定检测方法优化提取方法。
