气相色谱法分析食品中残留农药的方法研究
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摘要
农药残留量分析的第一个环节就是从样品中提取和净化痕量农药，以便进行分析测定。提取的好坏直接影响到分析结果的正确性。目前在残留农药分析中经常使用的分析方法，如薄层色谱、气相色谱、液相色谱、色谱-质谱联用等技术，一般均要求分析较净化的样品，否则存在的大量杂质会对残留农药的分析造成干扰或阻碍残留，有时还有损坏仪器的危险，因而提取、浓缩和净化是农药残留分析中一个十分重要的前处理步骤。液液萃取技术是一种成熟的复杂样品预处理技术，大约70％的农药残留分析现在仍采用它进行样品预处理。近年来，在农残分析方面出现了许多新的样品预处理技术，如加速溶剂提取(ASE)、微波提取(MAE)、固相萃取(SPE)、超临界流体萃取(SFE)、固相微萃取(SPME)、一滴溶剂萃取(SDE)等，它们各有自己的优缺点。本学位论文就液液萃取、固相微萃取和一滴溶剂萃取三种前处理技术进行较为系统的研究。
第一：采用液液萃取(LLE)气相色谱(CC)-电子捕获检测器(ECD)检测了武汉、广州两地柑橘上保鲜剂施保克及其降解产物的残留。该方法可以同时处理多个样品且不需大量的玻璃器皿和试剂、药品，比现有的方法更简捷、快速。获得线性范围为0.05-2.50mg／L，添加回收率为81.5-96.0％。同时我们还研究了实际样品的动态消解规律。测定结果表明：(1)25％施保克乳油1000mg／L浸果处理，储藏30天后，全果上的残留量为1.21-1.52mg／kg。全果上半衰期为69.3-88.6天；(2)25％施保克乳油500mg／L浸果处理，储藏30天后，全果上残留量为0.69-0.73mg／kg，全果上半衰期为55.5-57.5天；获得的检测限为0.002mg／kg。以上测定的残留动态数据第一次为我国储藏柑橘时上安全使用施保克提供了参考数据。
第二：根据文献本文对固相微萃取在农药残留方面的应用作了综述并采用固相微萃取与气相色谱-火焰光度检测器(SPME-GC-FPD)快速分析了蔬菜中有机磷杀虫剂。采用稀释的方法来减少蔬菜基质对SPME纤维头吸附分析物的干扰，获得了较好的回收率和精密度。该方法简单易行，不需要有机试剂，耗时短。方法灵敏度高。SPME方法还与传统的液液萃取(LLE)方法进行比较，得到SPME适合分析降解周期短的有机磷农药残留量。
d＼硕士学伎论文
＼扣方卜y ＊V厂R；＊卜厂
第三，采用一滴溶剂革取方法分析了蜂蜜中的有机氯杀虫剂，讨论了一滴
溶剂革取的各种影响因素。优化条件下在 0．5毛0．ODg／InL之间获得了较好的线性
范围，添加回收率实验发现六六六的各种异构体能获得引二3－93，63％的回收率
结果方法的检测限在0．56fig乃g刁．SUg／kg之间。一滴溶剂革取只需很少的有机
溶剂口习 ＞ 不对环境造成污染，不对分析人员的健康造成危害，而且克服了
SPME技术不能快捷分析有机氯农药的弱点，是一种分析六六六各种异构体残留
量的好方法。
The first step of retention analysis is to extract and clean up the trace pesticides. It has an direct effect on the accuracy of results. At present, the common methods, for example,Thin-film Chromatography,Gas Chromatography, liquid Chromatography and Gas Chromatography-Mass Spectrum, require analysing the purer samples. The complicated matrixes will interfere with the retention analyses and damage the instruments. So sampling, concentraction and purification are important prepraration steps in the retention analyses of pesticides. Liquid-Liquid Extraction is a typical and traditional method of preparation that deals with complicated samples. Now it is still used in 70% retention analyses of pesticides. Recently, lots of new techniques of prepraration have appeared, such as, Acceleration Solution Extration(ASE), Microwave Assisted Extraction (MAE), Supercritical Fluid Extraction (SFE), Solid Phase Extraction(SPE), Solid Phase Microextract ion (SPME), Single Drop Extraction(SDE) . These techniques have respective advantages and shortcomings . This thesis makes systematic research in the aspect of Liquid-liquid extraction, Solid Phase Microextract ion and Single Drop Extraction.
In the first place, This method aims at the Gas Chromatography method coupled with Liquid-liquid extraction with a electron capture detector of rapid detection of prochloraz and its degradation products in orange of Wuhan and Guangzhou. Using this simple and effective method, Many samples may be treated at one time without large quantities of glassware and solvent. Therefore it has more practical advantages than the previous methods. The rang of calibration curve is 0.05-2. 50mg/l, and the fortified recoveries are 81. 5-96.0%. At the same time, the rule of degradation is studied The results are as follows: (1)The orange are dipped in the
1000mg/l concentration, the retention amount of the whole fruit gets 1.21-1.52mg/kg after 30 days, and the half life of the whole fruit is 69.3-88.6 days; (2) The orange are dipped in the 500mg/l concentration, the retention amount of the whole fruit gets 0. 69-0. 73mg/kg after 30 days, and the half life of the whole fruit is 55.5-57.5 days; Detection limit of this method are 0.002mg/kg. The data obtained are able to supply the advice for the safe application of prochloraz in Chinese orange.
Then, this part sums up the application of Solid-phase microextration in the retention analysis of pesticide, and use SPME coupled with Gas Chromatograph and a flame photometric detector in phosphorous (GC-FPD)mode of rapid detection of organophosphorus insecticides residues in vegetable. The samples were diluted with water for the sake of reducing the interruption caused by vegetable matrix. Using this rapid and effective method without solvent, better recoveries ,better precisions and low Detection limit were obtained. At the same time, SPME was compared with the routine method, Liquid-liquid extraction, and the comparison result is that SPME is suitable method to the organophosphorus insecticides with the shorter degradation time.
Lastly, The part developed a new technique, called a Single drop extraction, to analyse organochlorinated pesticides in honey. This method discussed the varied correlative factors about Single-drop extraction. The rang of calibration curve is among 0.05-2. 50mg/l, Better recoveries of BHC in the honey were obtained under the optimistic conditions. The detection limit of the 4 iso-compounds of BHC has the rang of 0.56-L50ug/kg. Single-drop microextraction is an extraction technique that only need several microliter organic solvent(l-2ul). It can overcome the shortcomings of SPME when organochlorinated pesticides were analysed. The experimental results show a single drop extraction is acceptable method of retention analysis to BHC pesticides in honey.
第一：采用液液萃取(LLE)气相色谱(CC)-电子捕获检测器(ECD)检测了武汉、广州两地柑橘上保鲜剂施保克及其降解产物的残留。该方法可以同时处理多个样品且不需大量的玻璃器皿和试剂、药品，比现有的方法更简捷、快速。获得线性范围为0.05-2.50mg／L，添加回收率为81.5-96.0％。同时我们还研究了实际样品的动态消解规律。测定结果表明：(1)25％施保克乳油1000mg／L浸果处理，储藏30天后，全果上的残留量为1.21-1.52mg／kg。全果上半衰期为69.3-88.6天；(2)25％施保克乳油500mg／L浸果处理，储藏30天后，全果上残留量为0.69-0.73mg／kg，全果上半衰期为55.5-57.5天；获得的检测限为0.002mg／kg。以上测定的残留动态数据第一次为我国储藏柑橘时上安全使用施保克提供了参考数据。
第二：根据文献本文对固相微萃取在农药残留方面的应用作了综述并采用固相微萃取与气相色谱-火焰光度检测器(SPME-GC-FPD)快速分析了蔬菜中有机磷杀虫剂。采用稀释的方法来减少蔬菜基质对SPME纤维头吸附分析物的干扰，获得了较好的回收率和精密度。该方法简单易行，不需要有机试剂，耗时短。方法灵敏度高。SPME方法还与传统的液液萃取(LLE)方法进行比较，得到SPME适合分析降解周期短的有机磷农药残留量。
d＼硕士学伎论文
＼扣方卜y ＊V厂R；＊卜厂
第三，采用一滴溶剂革取方法分析了蜂蜜中的有机氯杀虫剂，讨论了一滴
溶剂革取的各种影响因素。优化条件下在 0．5毛0．ODg／InL之间获得了较好的线性
范围，添加回收率实验发现六六六的各种异构体能获得引二3－93，63％的回收率
结果方法的检测限在0．56fig乃g刁．SUg／kg之间。一滴溶剂革取只需很少的有机
溶剂口习 ＞ 不对环境造成污染，不对分析人员的健康造成危害，而且克服了
SPME技术不能快捷分析有机氯农药的弱点，是一种分析六六六各种异构体残留
量的好方法。
The first step of retention analysis is to extract and clean up the trace pesticides. It has an direct effect on the accuracy of results. At present, the common methods, for example,Thin-film Chromatography,Gas Chromatography, liquid Chromatography and Gas Chromatography-Mass Spectrum, require analysing the purer samples. The complicated matrixes will interfere with the retention analyses and damage the instruments. So sampling, concentraction and purification are important prepraration steps in the retention analyses of pesticides. Liquid-Liquid Extraction is a typical and traditional method of preparation that deals with complicated samples. Now it is still used in 70% retention analyses of pesticides. Recently, lots of new techniques of prepraration have appeared, such as, Acceleration Solution Extration(ASE), Microwave Assisted Extraction (MAE), Supercritical Fluid Extraction (SFE), Solid Phase Extraction(SPE), Solid Phase Microextract ion (SPME), Single Drop Extraction(SDE) . These techniques have respective advantages and shortcomings . This thesis makes systematic research in the aspect of Liquid-liquid extraction, Solid Phase Microextract ion and Single Drop Extraction.
In the first place, This method aims at the Gas Chromatography method coupled with Liquid-liquid extraction with a electron capture detector of rapid detection of prochloraz and its degradation products in orange of Wuhan and Guangzhou. Using this simple and effective method, Many samples may be treated at one time without large quantities of glassware and solvent. Therefore it has more practical advantages than the previous methods. The rang of calibration curve is 0.05-2. 50mg/l, and the fortified recoveries are 81. 5-96.0%. At the same time, the rule of degradation is studied The results are as follows: (1)The orange are dipped in the
1000mg/l concentration, the retention amount of the whole fruit gets 1.21-1.52mg/kg after 30 days, and the half life of the whole fruit is 69.3-88.6 days; (2) The orange are dipped in the 500mg/l concentration, the retention amount of the whole fruit gets 0. 69-0. 73mg/kg after 30 days, and the half life of the whole fruit is 55.5-57.5 days; Detection limit of this method are 0.002mg/kg. The data obtained are able to supply the advice for the safe application of prochloraz in Chinese orange.
Then, this part sums up the application of Solid-phase microextration in the retention analysis of pesticide, and use SPME coupled with Gas Chromatograph and a flame photometric detector in phosphorous (GC-FPD)mode of rapid detection of organophosphorus insecticides residues in vegetable. The samples were diluted with water for the sake of reducing the interruption caused by vegetable matrix. Using this rapid and effective method without solvent, better recoveries ,better precisions and low Detection limit were obtained. At the same time, SPME was compared with the routine method, Liquid-liquid extraction, and the comparison result is that SPME is suitable method to the organophosphorus insecticides with the shorter degradation time.
Lastly, The part developed a new technique, called a Single drop extraction, to analyse organochlorinated pesticides in honey. This method discussed the varied correlative factors about Single-drop extraction. The rang of calibration curve is among 0.05-2. 50mg/l, Better recoveries of BHC in the honey were obtained under the optimistic conditions. The detection limit of the 4 iso-compounds of BHC has the rang of 0.56-L50ug/kg. Single-drop microextraction is an extraction technique that only need several microliter organic solvent(l-2ul). It can overcome the shortcomings of SPME when organochlorinated pesticides were analysed. The experimental results show a single drop extraction is acceptable method of retention analysis to BHC pesticides in honey.
引文
[1]林玉锁，农药与生态环境保护，化学工业出版社
[2]费有春，徐映明等，农药问答(第三版)，化学工业出版社
[3]黄伟坤等，食品检验与分析，中国轻工业出版社
[4]樊得方，农药残留量分析与检测，上海科学技术出版社
[5]SUPLECO.提供
[6]D. Barcelo. J. Chromatogr. A, 117(1993)643
[7]M. A. Jeannot and F. P. Cantwell, Anal. Chem. 68(1996) 2236
[8]M. A. Jeannot and F. P. Cantwell, Anal. Chem. 69(1997) 235
[9]D. C. Leggett, T. F. Jenkins, P. H. Miyares, Anal. Chem. 62 (1990)1355.
[10]Y. Wang, Y. C. Kwok, Y. He, H. K. Lee, Anal. Chem. 70(1998) 4610.
[11] L. S. De Jager, A. R. J. Andrews, Chromat ographia, 50 (1999)733
[12]Y. He and H.K. Lee, Anal. Chem. 69(1997)4634
[2]费有春，徐映明等，农药问答(第三版)，化学工业出版社
[3]黄伟坤等，食品检验与分析，中国轻工业出版社
[4]樊得方，农药残留量分析与检测，上海科学技术出版社
[5]SUPLECO.提供
[6]D. Barcelo. J. Chromatogr. A, 117(1993)643
[7]M. A. Jeannot and F. P. Cantwell, Anal. Chem. 68(1996) 2236
[8]M. A. Jeannot and F. P. Cantwell, Anal. Chem. 69(1997) 235
[9]D. C. Leggett, T. F. Jenkins, P. H. Miyares, Anal. Chem. 62 (1990)1355.
[10]Y. Wang, Y. C. Kwok, Y. He, H. K. Lee, Anal. Chem. 70(1998) 4610.
[11] L. S. De Jager, A. R. J. Andrews, Chromat ographia, 50 (1999)733
[12]Y. He and H.K. Lee, Anal. Chem. 69(1997)4634