Multiresidue Determination of Organophosphorus Pesticide Residues in Vegetables and Fruit by Gas Chromatography-Negative Ion Chemical Ionization-Mass Spectrometry

将气相色谱-负离子化学电离质谱法(GC-NC I-M S)应用于蔬菜水果中9种有机磷农药残留的分析测定,初步解析了这些农药的NC I-M S特征阴离子结构和断裂机理,并初步探讨了GC-NC I-M S分析蔬菜水果中有机磷农药残留时基体效应的影响。采用空白样品基体匹配校准曲线法(M C)进行定量分析,有效地降低了基体效应的影响。蔬菜水果样品用乙酸乙酯超声提取,以乙硫磷为内标物,采用GC-NC I-M S的选择离子监测方式(S IM)进行定性和定量分析。9种有机磷农药的方法检测限为0.12~1.0μg/kg。在方法的检测限与1 000μg/kg范围内,线性相关系数都大于0.999 3。当空白蔬菜水果(西红柿)样品的加标水平为100,400,800μg/kg时,平均加标回收率为78%~126%,相对标准偏差为0.58%~14.7%。An analytical method of gas chromatography coupled with negative ion chemical ionization-mass spectrometry for simultaneous determination of nine organophosphorus pesticide residues in vegetables and fruit has been developed,and the negative ions structure and partition mechanism of the nine organophosphorus pesticides were interpreted.Meanwhile,the matrix effect for sample analysis was discussed,and matrix-matched calibration for quantification was introduced to reduce the matrix effect in this method.Pesticides were extracted from sample with ethyl acetate in an ultrasonic bath,then determined by gas chromatography-mass spectrometry operated in negative chemical ionization mode and quantified in selective ion monitoring mode,and ethion was used as an internal standard.The detection limits of the method were 0.12-1.0 μg/kg for the nine organophosphorus pesticides,and the relative coefficients were higher than(0.9993).A blank sample(tomato) was spiked at 100,400,800 μg/kg for each pesticide,and the recoveries were determined to be from 78% to 126% with relative standard deviations from 0.58% to 14.7% for the pesticides

Determination of Multiple Pesticide Residues in Honey Using Gas Chromatography-Mass Spectrometry

开展了蜂蜜中23种农药残留的气相色谱-电子轰击离子源质谱(GC-E I/M S)分析方法的研究,并对其中3种农药的E I/M S碎片离子的断裂机理与结构进行了初步解析。探讨了蜂蜜试样前处理条件的优化与选择。将蜂蜜试样用乙酸乙酯提取剂超声提取、F lo ris il硅藻土色谱柱净化和正己烷-乙酸乙酯(体积比为7∶3)混合洗脱剂洗脱后,以PCB103为内标物,采用选择离子监测(S IM)方式下的GC-E I/M S分析。当试样的加标浓度为50,100和200μg/kg时,加标回收率为82%~120%,相对标准偏差小于11.0%。23种农药的检测限都小于10.0μg/kg,线性范围为10~500μg/kg,相关系数都大于0.995。此分析方法已成功地应用于蜂蜜中23种痕量农药残留的分析。An analytical method was developed for the simultaneous determination of 23 pesticide residues in various commercial honeys.Meanwhile,the characteristic ions and fragmentation mechanism of three pesticides in the process of electron ionization mass spectrometry(EI/MS) were evaluated.After the optimization of different parameters such as the extraction solvent,pesticides were extracted from honey with ethyl acetate in an ultrasonic bath,cleaned up on a Florisil column by an elution of mixture of hexane and ethyl acetate(7∶ 3,v/v), and analyzed by gas chromatography-electron ionization mass spectrometry(GCEI/MS) in the selected ion monitoring mode(SIM) with PCB103 as internal standard.Recovery studies were performed at 50,100 and 200 μg/kg fortification levels for each pesticide,and the recoveries ranged from 82% to 120% with relative standard deviations between 1.8% and 11.0% for different pesticides.The limit of detection was less than 10.0 μg/kg for all the pesticides.The developed method was linear in the range of 10-500 μg/kg,with correlation coefficients larger than 0.995.Finally,the developed analytical method has been successfully applied to the determination of pesticide residues in several honey samples

Cooperation Strategic Research on Physical Education in High Schools between Vietnam and Guangxi

国际教育合作是全球化背景下高等教育发展的必然趋势,也是高校提升竞争力开拓国际教育服务贸易市场的重要方式。本文从战略合作的视角出发,提出了教育资源共享战略与特色战略为广西与越南开展高校体育教育合作提供了战略选择路径。International cooperation in higher education has been an inevitable trend in the process of globalization, and it is also an important way for high schools to promote education competitive forces of enlarging services market in international education trade. From perspective of cooperation strategy, the paper studies sharing-education-resource strategy and feature strategy in order to provide strategic references to the cooperation in high schools between Guangxi and Vietnam.广西哲学社会科学规划项目“广西与越南高校体育教育合作问题与对策研究”资助,项目编号:08BTY00

北部湾经济区高尔夫产业化发展对策研究

1高尔夫产业化的概念高尔夫产业化是通过对高尔夫自身规模组织的改造,实现向产业部门的转化,从而成为国民经济的一个部门或有机组成部分的过程。2北部湾经济区高尔夫发展的SWOT分析优势:北部湾经济区气候条件十分利于高尔夫运动的开展,高尔夫球场的地形也具多样性、风格独特,而且休闲旅游配套完善。劣势:高尔夫经营种类单一,高尔夫球具服装的制造以及高尔夫经纪业都未得到应有的发展,举办高尔夫职业赛事、全国