HPLC检测枇杷中氯吡脲含量的前处理方法

Pretreatment method of forchlorfenuron residues in loquat by HPLC analysis

建立合适的样品提取和净化条件是确保高效液相色谱（high-performance liquid chromatography,HPLC）检测方法准确的重要条件。为了研究枇杷果实中氯吡脲残留HPLC检测的前处理方法,通过对比基质分散固相萃取和QuEChERS（quick,easy,cheap,effective,rugged,safe）2种处理方法对枇杷中氯吡脲残留的检测效果,确定适合的前处理方法。结果表明,QuEChERS前处理方法的平均回收率显著高于基质分散固相萃取法,适于枇杷中氯吡脲的残留检测。针对QuEChERS前处理方法,比较了不同提取及净化条件对枇杷中氯吡脲提取率的影响,确定其最适条件为：8g枇杷果实用16mL乙腈提取20min,然后用无水硫酸镁和氯化钠比例为3∶2的盐析脱水,最后用PSA和C18比例为1∶1净化3min。经验证,氯吡脲与杂质分离效果较好,回收率稳定在80%~100%之间,变异系数为3.1%~4.8%,表明本方法可有效提取和净化枇杷中的氯吡脲残留。

Forchlorfenuron,1-（2-chloro-4-pyridyl）-3-phenyl,is a multipurpose plant growth regulator.The previous reports showed that forchlorfenuron was a relatively safe and low-toxic pesticide without teratogenic and mutagenic effects on human and animals. However,recent researches showed that excessive exposure of forchlorfenuron could cause the disorder of protein metabolism,mild emphysema.Therefore,residue detection of forchlorfenuron in fruits and vegetables is imperative.High-performance liquid chromatography（HPLC）analysis is a common detection method.The suitable conditions for the extraction and purification of sample play an important role prior to HPLC analysis.In this study,the extraction efficiency of forchlorfenuron residues in loquat was compared using matrix dispersive solid phase extraction and QuEChERS（quick,easy,cheap,effective,rugged,safe）.The results showed that QuEChERS was a more suitable pretreatment method for the determination of forchlorfenuron residues in loquat,because it had obviously higher average recoveries than the matrix dispersive solid phase extraction.Effects of different extraction and purification conditions on QuEChERS were further studied.The optimal conditions obtained were that 8.0g of loquat samples were extracted with 16 mL of acetonitrile for 20 min,and then salted out for dehydration by m（anhydrous magnesium sulfate）∶m（sodium chloride）=3∶2,and ultimately purified by m（primary secondary amine（PSA））∶m（C18）=1∶1for 3min.The forchlorfenuron residues in loquat could be completely separated from impurities under these optimal conditions,and furthermore,the spiked recoveries of forchlorfenuron in loquat were80%-100%,with coefficient of variation（CV）in the range of 3.1%-4.8%.It was concluded that our method of pretreatment could effectively extract and purify forchlorfenuron residues in loquat.