Environmental Research Group, Department of Chemistry, University of Malaya, Kuala Lumpur 50603, Malaysia.
J Hazard Mater. 2011 Feb 28;186(2-3):1308-13. doi: 10.1016/j.jhazmat.2010.12.001. Epub 2010 Dec 8.
A simple and effective multiresidue method based on precipitation at low temperature followed by matrix solid-phase dispersion-sonication was developed and validated to determine dimethoate, malathion, carbaryl, simazine, terbuthylazine, atrazine and diuron in palm oil using liquid chromatography time-of-flight mass spectrometry (LC-TOF-MS). Liquid-liquid extraction (LLE) followed by low temperature method were optimized by studying the effect of type and volume of organic solvent (acetonitrile, acetonitrile:n-hexane (3:2 v/v) and acetone) and time of freezing to obtain high recovery yield and low co-extract fat residue in the final extract. The optimal conditions for matrix solid-phase dispersion (MSPD) were obtained using 5 g of palm oil, 2 g of primary secondary amine (PSA) as dispersing sorbent, 1 g of graphitized carbon black (GCB) as clean-up sorbent and 15 mL of acetonitrile as eluting solvent under conditions of 15 min ultrasonication at room temperature. Method validation was performed in order to study sensitivity, linearity, precision, and accuracy. Average recoveries at three concentration levels (25, 50 and 100 μg kg(-1)) were found in the range of 72.6-91.3% with relative standard deviations between 5.3% and 14.2%. Detection and quantification limits ranged from 1.5 to 5 μg kg(-1) and from 2.5 to 9 μg kg(-1), respectively.
建立并验证了一种基于低温沉淀结合基质固相分散-超声提取的简单、有效的多残留分析方法，用于检测棕榈油中的乐果、马拉硫磷、西玛津、涕灭威、特丁津、阿特拉津和敌草隆。采用液相色谱飞行时间质谱（LC-TOF-MS）进行分析。通过研究不同有机溶剂（乙腈、乙腈-正己烷（3:2 v/v）和丙酮）的类型和体积以及冷冻时间对提取效率的影响，优化了液液萃取（LLE）和低温沉淀法，以获得高回收率和低脂肪残留。采用 5 g 棕榈油、2 g 初级/次级胺（PSA）作为分散吸附剂、1 g 石墨化炭黑（GCB）作为净化吸附剂，15 mL 乙腈作为洗脱溶剂，在室温下超声提取 15 min，得到最佳的基质固相分散（MSPD）条件。对方法进行了灵敏度、线性、精密度和准确度的验证。在 25、50 和 100 μg/kg 三个浓度水平下，平均回收率在 72.6%-91.3%之间，相对标准偏差在 5.3%-14.2%之间。检测限和定量限分别为 1.5-5 μg/kg 和 2.5-9 μg/kg。
