【摘要】 建立超声萃取—气流式微注射萃取—在线气相色谱质谱联用(GPMSE—GC—MS)快速测定蔬菜中代表性有机磷农药残留的检测方法。样品经乙酸乙酯超声提取,气流微注射萃取仪(GP—MSE)净化、富集,在线以气相色谱质谱的选择监控离子模式进行定性定量测定。考察GP—MSE的气流速率、样品相温度、萃取时间、萃取溶剂等因素对萃取效率的影响,以10μL的正己烷为萃取、富集溶剂,GP—MSE的气体流速2.0min/mL,萃取相温度250℃,萃取时间为3min,在线进样进行GC—MS分析。结果表明,28种农药在各自的线性范围内线性关系良好(相关系数不低于0.99),检出限(以信噪比(S/N)为3计算为0.3~1.2μg/kg,定量限(S/N=10)为3.0~10.0μg/kg。在两种基质(大白菜、芹菜)中3个添加水平下的回收率为80.2%~122.6%,相对标准偏差为1.6%~12.1%。与固相萃取比较。该方法提取效率高,定性定量准确、灵敏,可实现对蔬菜中多农药残留的快速检测,对保障蔬菜安全,促进蔬菜出口具有重要意义。更多还原

【Abstract】 An analysis method was established on rapid determination of organophosphorus pesticides(OPPs)residues in vegetables using ultrasonic extraction and gas flow liquid phase microextraction coupled with on-line gas chromatography-mass spectrometry(UAEGPMSE-GC- MS).The samples were extracted by ultrasonic techniques with ethyl acetate and re-extracted by gas flow liquid phase microextraction(also known as gas flow-microsyringe extraction,GP-MSE)for purification and enrichment.The optimal conditions of the GP-MSE were as follows:10μL of n-hexane was used as an enrichment solvent,the gas flow rate was 2.0min/mL,the temperature of the sample phase was 250℃,and the extraction time was 3min.Then,the secondary extraction was directly injected into gas chromatography-mass spectrometry(GC-MS)system,and 28 types of OPPs in vegetable samples were determined in selected ion mode(SIM).The UAE-GPMSE-GC-MS analysis system demonstrated a good linear relationship(the correlation coefficient not less than 0.99),and the detection limits(S/N=3)and the quantification limits(S/N=10)were 0.3~1.2μg/kg and 3.0~1 0μg/kg,respectively.Finally,the analysis system was used for the analysis of real samples and compared with solid phase extraction.The recoveries of OPPs in different vegetable samples ranged from 80.2%to122.6%,and the relative standard deviations(RSDs)ranged from1.6%to 12.1%.The research provided a highly efficient,accurate,and sensitive quantitative analysis method for the rapid determination of OPPs in vegetables,which is notably important for maintaining vegetable safety.更多还原