REQUIMTE, Department of Bromatology, Faculty of Pharmacy, University of Porto, 4099-030 Porto, Portugal.
Food Addit Contam Part A Chem Anal Control Expo Risk Assess. 2011 Apr;28(4):513-26. doi: 10.1080/19440049.2010.542551. Epub 2011 Feb 17.
The purpose of this study was to establish a reliable, cost-effective, fast and simple method to quantify simultaneously both bisphenol A (BPA) and bisphenol B (BPB) in liquid food matrixes such as canned beverages (soft drinks and beers) and powdered infant formula using dispersive liquid-liquid micro-extraction (DLLME) with in-situ derivatisation coupled with heart-cutting gas chromatography-mass spectrometry (GC-MS). For the optimisation of the DLLME procedure different amounts of various extractive and dispersive solvents as well as different amounts of the derivative reagent were compared for their effects on extraction efficiency and yields. The optimised procedure consisted of the injection of a mixture containing tetrachloroethylene (extractant), acetonitrile (dispersant) and acetic anhydride (derivatising reagent) directly into an aliquot of beverage samples or into an aqueous extract of powdered milk samples obtained after a pretreatment of the samples. Given the compatibility of the solvents used, and the low volumes involved, the procedure was easily associated with GC-MS end-point determination, which was accomplished by means of an accurate GC dual column (heart-cutting) technique. Careful optimisation of heart-cutting GC-MS conditions, namely pressure of front and auxiliary inlets, have resulted in a good analytical performance. The linearity of the matrix-matched calibration curves was acceptable, with coefficients of determination (r2) always higher than 0.99. Average recoveries of the BPA and BPB spiked at two concentration levels into beverages and powdered infant formula ranged from 68% to 114% and the relative standard deviation (RSD) was <15%. The limits of detection (LOD) in canned beverages were 5.0 and 2.0 ng l(-1) for BPA and BPB, respectively, whereas LOD in powdered infant formula were 60.0 and 30.0 ng l(-1), respectively. The limits of quantification (LOQ) in canned beverages were 10.0 and 7.0 ng l-1 for BPA and BPB, respectively, whereas LOQ in powdered infant formula were 200.0 and 100.0 ng l(-1), respectively. BPA was detected in 21 of 30 canned beverages (ranging from 0.03 to 4.70 µg l(-1)) and in two of seven powdered infant formula samples (0.23 and 0.40 µg l(-1)) collected in Portugal. BPB was only detected in canned beverages being positive in 15 of 30 samples analysed (ranging from 0.06 to 0.17 µg l(-1)). This is the first report about the presence of BPA and BPB in canned beverages and powdered infant formula in the Portuguese market.
本研究旨在建立一种可靠、经济、快速且简单的方法，使用分散液-液微萃取（DLLME）结合原位衍生化和中心切割气相色谱-质谱（GC-MS）同时定量分析罐装饮料（软饮料和啤酒）和粉状婴儿配方等液体食品基质中的双酚 A（BPA）和双酚 B（BPB）。为了优化 DLLME 程序，比较了不同量的各种萃取和分散溶剂以及不同量的衍生试剂对萃取效率和产率的影响。优化后的程序包括直接将含有四氯乙烯（萃取剂）、乙腈（分散剂）和乙酸酐（衍生试剂）的混合物注入饮料样品的等分试样中，或注入经预处理的粉状奶粉样品的水溶液中。鉴于所用溶剂的相容性以及涉及的低体积，该程序很容易与 GC-MS 终点测定相关联，这是通过准确的 GC 双柱（中心切割）技术完成的。仔细优化中心切割 GC-MS 条件，即前入口和辅助入口的压力，已得到良好的分析性能。基质匹配校准曲线的线性关系可接受，决定系数（r2）始终高于 0.99。BPA 和 BPB 分别以两个浓度水平添加到饮料和粉状婴儿配方中的平均回收率在 68%至 114%之间，相对标准偏差（RSD）<15%。罐装饮料中 BPA 和 BPB 的检出限（LOD）分别为 5.0 和 2.0 ng l(-1)，而粉状婴儿配方中的 LOD 分别为 60.0 和 30.0 ng l(-1)。罐装饮料中 BPA 和 BPB 的定量限（LOQ）分别为 10.0 和 7.0 ng l(-1)，而粉状婴儿配方中的 LOQ 分别为 200.0 和 100.0 ng l(-1)。在葡萄牙收集的 30 罐饮料中的 21 种（范围为 0.03 至 4.70 µg l(-1))和 7 种粉状婴儿配方中的 2 种（0.23 和 0.40 µg l(-1))中检测到 BPA。BPB 仅在罐装饮料中被检出，在分析的 30 个样品中有 15 个呈阳性（范围为 0.06 至 0.17 µg l(-1))。这是首次报道 BPA 和 BPB 存在于葡萄牙市场的罐装饮料和粉状婴儿配方中。
