Zhang Cheng, Cagliero Cecilia, Pierson Stephen A, Anderson Jared L
Department of Chemistry, Iowa State University, Ames, IA 50011, USA.
Dipartimento di Scienza e Tecnologia del Farmaco, Universtà degli Studi di Torino, I-10125, Torino, Italy.
J Chromatogr A. 2017 Jan 20;1481:1-11. doi: 10.1016/j.chroma.2016.12.013. Epub 2016 Dec 8.
A simple and rapid ionic liquid (IL)-based in situ dispersive liquid-liquid microextraction (DLLME) method was developed and coupled to headspace gas chromatography (HS-GC) employing electron capture (ECD) and mass spectrometry (MS) detection for the analysis of polychlorinated biphenyls (PCBs) and acrylamide at trace levels from milk and coffee samples. The chemical structures of the halide-based ILs were tailored by introducing various functional groups to the cations to evaluate the effect of different structural features on the extraction efficiency of the target analytes. Extraction parameters including the molar ratio of IL to metathesis reagent and IL mass were optimized. The effects of HS oven temperature and the HS sample vial volume on the analyte response were also evaluated. The optimized in situ DLLME method exhibited good analytical precision, good linearity, and provided detection limits down to the low ppt level for PCBs and the low ppb level for acrylamide in aqueous samples. The matrix-compatibility of the developed method was also established by quantifying acrylamide in brewed coffee samples. This method is much simpler and faster compared to previously reported GC-MS methods using solid-phase microextraction (SPME) for the extraction/preconcentration of PCBs and acrylamide from complex food samples.
开发了一种基于离子液体（IL）的简单快速原位分散液液微萃取（DLLME）方法，并将其与顶空气相色谱（HS-GC）联用，采用电子捕获（ECD）和质谱（MS）检测，用于分析牛奶和咖啡样品中痕量的多氯联苯（PCBs）和丙烯酰胺。通过向阳离子中引入各种官能团来定制基于卤化物的离子液体的化学结构，以评估不同结构特征对目标分析物萃取效率的影响。优化了包括离子液体与复分解试剂的摩尔比和离子液体质量在内的萃取参数。还评估了顶空炉温度和顶空样品瓶体积对分析物响应的影响。优化后的原位DLLME方法具有良好的分析精度、线性，对于水样品中的多氯联苯，检测限低至低皮克级，对于丙烯酰胺，检测限低至低纳克级。通过对冲泡咖啡样品中的丙烯酰胺进行定量，也确定了所开发方法的基质兼容性。与先前报道的使用固相微萃取（SPME）从复杂食品样品中萃取/预浓缩多氯联苯和丙烯酰胺的气相色谱-质谱（GC-MS）方法相比，该方法要简单得多且速度更快。
