Departamento de Química Inorgánica y Analítica, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago, Casilla 233, Chile.
J Chromatogr A. 2009 Dec 18;1216(51):8859-66. doi: 10.1016/j.chroma.2009.10.082. Epub 2009 Nov 1.
An effective extraction method was devised for the determination of organophosphorus pesticides (OPPs) in olive and avocado oil samples, using atmospheric pressure microwave-assisted liquid-liquid extraction (APMAE) and solid-phase extraction or low-temperature precipitation as clean-up step. A simple glass system equipped with an air-cooled condenser was designed as an extraction vessel. The pesticides were partitioned between acetonitrile and oil solution in hexane. Analytical determinations were carried out by gas chromatography-flame photometric detection and gas chromatography-tandem mass spectrometry, using a triple quadrupole mass analyzer, for confirmation purposes. Several factors influencing the extraction efficiency were investigated and optimized through fractional factorial design and Doehlert design. Under optimal conditions the recovery of pesticides from oil at 0.025 microg g(-1) ranged from 71% to 103%, except for fenthion in avocado oil, with RSDs < or = 13% (n=5). The LOQ for the entire method ranged from 0.004 to 0.015 microg g(-1). Finally, the proposed method was successfully applied to the extraction and determination of the selected pesticides in 20 commercially packed extra virgin olive oils and four commercially packed avocado oils produced in Chile. Detectable residues of different OPPs were observed in 85% of samples.
设计了一种有效的提取方法，用于测定橄榄油和鳄梨油样品中的有机磷农药（OPPs），采用常压微波辅助液 - 液萃取（APMAE）和固相萃取或低温沉淀作为净化步骤。设计了一种简单的玻璃系统，配备风冷冷凝器，作为萃取容器。农药在乙腈和正己烷中的油溶液之间分配。采用三重四极杆质量分析仪进行气相色谱 - 火焰光度检测和气相色谱 - 串联质谱分析，用于确证目的。通过部分因子设计和 Doehlert 设计研究并优化了影响萃取效率的几个因素。在最佳条件下，从 0.025μg g（-1）的油中农药的回收率为 71％至 103％，除了鳄梨油中的 fenthion，RSDs <或= 13％（n=5）。整个方法的 LOQ 范围为 0.004 至 0.015μg g（-1）。最后，该方法成功应用于智利生产的 20 种商业包装特级初榨橄榄油和 4 种商业包装鳄梨油中选定农药的提取和测定。在 85％的样品中观察到不同 OPPs 的可检测残留。
