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    离子液体分散液液微萃取-水相固化-高效液相色谱法测定食用菌中3种拟除虫菊酯类农药的残留量

    HPLC Determination of Residual Amounts of 3 Pyrethroids in Edible Fungi with Ionic Liquid Dispersive Liquid Liquid Microextraction Based on Solidification of Aqueous Phase

    • 摘要: 粉碎匀浆后的食用菌样品用乙腈涡旋提取。提取液与离子液体1-己基-3-甲基咪唑六氟磷酸盐混合后注入5 mL水中,再加入50 mg的氯化钠,完成分散液液微萃取。离心后离子液体沉于离心管底部,取出水相中大部分水,将离心管放置于-20 ℃冰箱中,待上层水相固化后,取出底部全部的离子液体,用甲醇稀释。采用高效液相色谱法测定稀释液中3种拟除虫菊酯类农药的残留量。以Eclipse Plus C18色谱柱为分离柱,以95%(体积分数)乙腈溶液为流动相,在测定波长230 nm处进行测定。3种拟除虫菊酯类农药的质量分数均在50~5 000 μg·kg-1内与其对应的峰面积呈线性关系,检出限(3S/N)为1.0~1.4 μg·kg-1,测定下限(10S/N)为3.2~4.7 μg·kg-1。以空白样品为基体进行加标回收试验,所得回收率为71.6%~92.7%,测定值的相对标准偏差(n=5)为0.050%~6.6%。

       

      Abstract: The pulverized and homogenized edible fungi sample was extracted with acetonitrile by vortex agitation. The extract was mixed with the ionic liquid [HMIM]PF6, and then injected into 5 mL of water. After adding 50 mg of NaCl, the dispersive liquid liquid microextraction was completed. After centrifugation, the ionic liquid settled onto the bottom of the centrifuge tube. Most of the water in the aqueous phase was removed, and then centrifuge tube was put into freezer (-20 ℃). After the upper aqueous phase was solidified, the ionic liquid at the bottom was taken completely, and diluted by methanol. HPLC was applied to the determination of residual amounts of 3 pyrethroids in the diluent. Eclipse Plus C18 chromatographic column was used as separation column, and 95% (φ) acetonitrile solution was used as mobile phase. Detection at 230 nm was adopted in the determination. Linear relationships between values of peak area and mass fraction of 3 pyrethroids were kept in the same range of 50-5 000 μg·kg-1, with detection limits (3S/N) in the range of 1.0-1.4 μg·kg-1 and lower limits of determination (10S/N) in the range of 3.2-4.7 μg·kg-1. On the base of blank sample, test for recovery was made by standard addition method; values of recovery found were in the range of 71.6%-92.7%, with RSDs (n=5) of determined values in the range of 0.050%-6.6%.

       

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