摘要 [目的]建立柱前衍生高效液相色譜-熒光法測(cè)定煙葉和土壤中甲氨基阿維菌素苯甲酸鹽殘留量的方法。[方法]樣品經(jīng)乙腈提取，分散固相萃取凈化，以N-甲基咪唑和三氟乙酸酐進(jìn)行柱前衍生，衍生物用高效液相色譜-熒光法測(cè)定。[結(jié)果]當(dāng)添加濃度為0000 5～1.000 0 mg/kg時(shí)，甲氨基阿維菌素苯甲酸鹽的平均添加回收率均超過(guò)90%，相對(duì)標(biāo)準(zhǔn)偏差（RSD）為2.3%～5.5%。在鮮煙葉、干煙葉和土壤中，方法最低檢出濃度（LOQ）分別為0.004、0.008和0.000 5 mg/kg。采用所建方法測(cè)定了2014～2015年山東、四川煙葉和土壤樣品中甲氨基阿維菌素苯甲酸鹽的消解動(dòng)態(tài)及最終殘留，結(jié)果表明，甲氨基阿維菌素苯甲酸鹽在煙葉和土壤中消解半衰期為4.4～5.4和1.6～2.6 d。按照2.25和3.375 g a.i./hm2用量，分別施藥2～3次，采收間隔期 7 d時(shí)，烤后煙葉樣品中甲氨基阿維菌素苯甲酸鹽殘留量低于0.2 mg/kg。[結(jié)論]該方法操作簡(jiǎn)便，有機(jī)溶劑用量少，符合農(nóng)藥殘留檢測(cè)技術(shù)對(duì)靈敏度、準(zhǔn)確度及精密度的要求。
　　關(guān)鍵詞 高效液相色譜-熒光法；甲氨基阿維菌素苯甲酸鹽；煙葉；土壤；殘留；消解
　　中圖分類號(hào) S482.3 文獻(xiàn)標(biāo)識(shí)碼
　　A 文章編號(hào) 0517-6611（2016）17-070-03
　　Abstract [Objective] To establish a high performance liquid chromatography with fluorescence detection （HPLC-FLD） method for the determination of emamectin benzoate residue in tobacco leaves and soil. [Method] The sample was extracted by acetonitrile and then cleaned up by dispersive solid phase extraction. After pre column derivatization with N-methyl imidazole and three trifluoroacetic anhydride，the derivatives were determined by HPLC-FLD. [Result] In the range of 0.000 5-1.000 mg/kg，the average recoveries of emamectin benzoate were higher than 90%，with the relative standard deviation （RSD） 2.3%-5.5%. The limits of quantification （LOQ） of emamectin benzoate in fresh tobacco leaves，cured tobacco leaves and soil were 0.004，0.008 and 0.000 5 mg/kg，respectively. The dissipation and residue levels of emamectin benzoate in Shandong and Sichuan in 2014-2015 were investigated using the established method. The field trials results showed that the half-lives of emamectin benzoate in tobacco leaves and soil were 4.4-5.4 day and 1.6-2.6 day，respectively. When applied at the dosage of 2.25 and 3375 g a.i./ hm2 for 2-3 times，the terminal residues of emamectin benzoate in cured tobacco leaves with a pre-harvest interval of 7 days were lower than 0.2 mg/kg. [Conclusion] This method has the characteristics of simple operation，small dosage of organic solvent，which meets the requirements of sensitivity，accuracy and precision of pesticide residues detection technology.
　　Key words HPLC-FLD； Emamectin benzoate； Tobacco leaf； Soil； Residue； Degradation
　　甲氨基阿維菌素苯甲酸鹽（簡(jiǎn)稱甲維鹽）是以阿維菌素為原料，經(jīng)化學(xué)合成的一種高效殺蟲(chóng)殺螨劑[1]，其作用機(jī)理為阻礙害蟲(chóng)運(yùn)動(dòng)神經(jīng)系統(tǒng)傳遞而使其麻痹死亡，具有胃毒、觸殺和一定的滲透作用。甲維鹽對(duì)鱗翅目、鞘翅目、同翅目等害蟲(chóng)具有顯著防效，在水果、蔬菜、煙草以及大田作物中得到了廣泛應(yīng)用[2] 。
　　目前，甲維鹽的分析方法常采用高效液相色譜分離，紫外檢測(cè)器（UV）[3-5]或熒光檢測(cè)器（FLD）[6-7]進(jìn)行檢測(cè)。當(dāng)使用紫外檢測(cè)器（UV）進(jìn)行檢測(cè)時(shí)，由于雜質(zhì)干擾大、靈敏度低，需要進(jìn)行較為復(fù)雜的凈化和濃縮步驟，程序繁瑣，消耗大量有機(jī)溶劑[8-9]。而目前報(bào)道的衍生化方法中，應(yīng)用范圍也以蔬菜、水果和土壤為主[10-13]。筆者首次將分散固相萃取凈化與熒光檢測(cè)相結(jié)合，建立了煙草和土壤中甲維鹽的分析方法，具有快速、簡(jiǎn)便、靈敏、可靠的特點(diǎn)，并采用所建方法研究3.4%甲維鹽懸浮劑在煙草上應(yīng)用時(shí)的消解動(dòng)態(tài)與最終殘留水平，為推薦該農(nóng)藥制定合理使用規(guī)范提供基礎(chǔ)數(shù)據(jù)。

相關(guān)熱詞搜索：苯甲酸 高效 消解 煙葉 氨基