Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Khon Kaen University, Khon Kaen 40002, Thailand.
Talanta. 2012 Jan 15;88:209-15. doi: 10.1016/j.talanta.2011.10.033. Epub 2011 Oct 31.
Dispersive liquid-liquid microextraction (DLLME) coupled to high performance liquid chromatography (HPLC) with UV detection was applied for the determination of six pyrethroids (tetramethrin, fenpropathrin, cypermethrin, deltamethrin, fenvalerate and permethrin) in various fruit juices including apple, red grape, orange, kiwi, passion fruit, pomegranate and guava juice. Six pyrethroids were separated within 30 min using a Waters Atlantis T3 column under an isocratic elution of acetonitrile-water (72:28). The parameters affecting extraction efficiency of the DLLME method such as type of disperser and extraction solvent, volume of disperser and extraction solvent and centrifugation time were investigated. Under the optimum conditions, 5.00 mL of sample solution, 300 μL of chloroform as extraction solvent and 1.25 mL of methanol as dispersive solvent gave high enrichment factor in the range of 62-84. Good linearity was obtained from 2 to 1,500 μg/L (r(2)>0.995). The mean recoveries of the pyrethroids evaluated by fortification of real samples were in the range of 84-94%. The limits of detection ranging from 2 to 5 μg/L are sufficient to analyze pyrethroid residues at the maximum residue limits (MRLs) established by the European Union (EU) in fruit juices. The proposed method can be applied to direct determination of pyrethroid residues in fruit juices.
分散液液微萃取（DLLME）与高效液相色谱（HPLC）结合，采用紫外检测法，用于测定苹果、红葡萄、橙子、猕猴桃、百香果、石榴和番石榴汁等各种果汁中的六种拟除虫菊酯（四氟甲醚菊酯、甲氰菊酯、氯菊酯、溴氰菊酯、氰戊菊酯和溴氰菊酯）。在等度洗脱条件下，使用 Waters Atlantis T3 柱在 30 分钟内分离六种拟除虫菊酯，洗脱液为乙腈-水（72:28）。研究了影响 DLLME 方法萃取效率的参数，如分散剂和萃取溶剂的类型、分散剂和萃取溶剂的体积以及离心时间。在最佳条件下，5.00 mL 样品溶液、300 μL 氯仿作为萃取溶剂和 1.25 mL 甲醇作为分散溶剂，可获得 62-84 的高富集因子。从 2 至 1500 μg/L（r²＞0.995）范围内获得良好的线性关系。通过对实际样品进行加标评估，拟除虫菊酯的平均回收率在 84-94%之间。检测限范围为 2-5 μg/L，足以分析果汁中拟除虫菊酯残留量达到欧盟规定的最大残留限量（MRLs）。该方法可用于直接测定果汁中的拟除虫菊酯残留量。
