Montes R, Rodríguez I, Ramil M, Rubí E, Cela R
Departamento de Química Analítica, Nutrición y Bromatología, Instituto de Investigación y Análisis Alimentario, Universidad de Santiago de Compostela, Santiago de Compostela 15782, Spain.
J Chromatogr A. 2009 Jul 17;1216(29):5459-66. doi: 10.1016/j.chroma.2009.05.048. Epub 2009 May 29.
A novel approach for the determination of seven fungicides (metalaxyl-M, penconazole, folpet, diniconazole, propiconazole, difenoconazole and azoxystrobin) in wine samples is presented. Analytes were extracted from the matrix and transferred to a small volume of a high density, water insoluble solvent using solid-phase extraction (SPE) followed by dispersive liquid-liquid microextraction (DLLME). Variables affecting the performance of both steps were thoroughly investigated (metalaxyl-M was not included in some optimisation studies) and their effects on the selectivity and efficiency of the whole sample preparation process are discussed. Under optimised conditions, 20 mL of wine were first concentrated using a reversed-phase sorbent and then target compounds were eluted with 1 mL of acetone. This extract was mixed with 0.1 mL of 1,1,1-trichloroethane (CH(3)CCl(3)) and the blend added to 10 mL of ultrapure water. After centrifugation, an aliquot (1-2 microL) of the settled organic phase was analyzed by gas chromatography (GC) with electron capture (ECD) and mass spectrometry (MS) detection. The method provided enrichment factors (EFs) around 200 times and an improved selectivity in comparison to use of SPE as single sample preparation technique. Moreover, the yield of the global process was similar for red and white wine samples and the achieved limits of quantification (LOQs) (from 30 to 120 ngL(-1) and from 40 to 250 ngL(-1), for GC-ECD and GC-MS, respectively) were low enough for the determination of target species in commercial wines. Among compounds considered in this work, metalaxyl-M and azoxystrobin were found in several wines at concentrations from 0.8 to 32 ngmL(-1).
本文提出了一种测定葡萄酒样品中七种杀菌剂（精甲霜灵、戊唑醇、福美双、烯唑醇、丙环唑、苯醚甲环唑和嘧菌酯）的新方法。使用固相萃取（SPE），然后进行分散液液微萃取（DLLME），从基质中提取分析物，并转移到少量高密度、水不溶性溶剂中。深入研究了影响这两个步骤性能的变量（在一些优化研究中未包括精甲霜灵），并讨论了它们对整个样品制备过程的选择性和效率的影响。在优化条件下，首先使用反相吸附剂对20 mL葡萄酒进行浓缩，然后用1 mL丙酮洗脱目标化合物。将该提取物与0.1 mL 1,1,1-三氯乙烷（CH(3)CCl(3)）混合，并将混合物加入10 mL超纯水中。离心后，取沉降有机相的等分试样（1 - 2 μL），通过气相色谱（GC）结合电子捕获（ECD）和质谱（MS）检测进行分析。与使用SPE作为单一样品制备技术相比，该方法提供了约200倍的富集因子（EFs），并提高了选择性。此外，红葡萄酒和白葡萄酒样品的整体回收率相似，实现的定量限（LOQs）（GC - ECD和GC - MS分别为30至120 ngL(-1)和40至250 ngL(-1)）足够低，可用于测定商业葡萄酒中的目标物质。在本研究考虑的化合物中，在几种葡萄酒中发现精甲霜灵和嘧菌酯的浓度为0.8至32 ngmL(-1)。
