【作者】 冯海强；

【导师】 王校常；

【作者基本信息】 浙江大学 ， 茶学， 2010， 硕士

【摘要】 近年来,随着食品全方面的关注,农药特别是高毒的有机磷农药限量标准越来越严格,对农药痕量检测方法要求也越来越高。典型的农残检测方法,从萃取、净化、浓缩再到检测,分析时间长、操作繁琐；而现在的快速检测方法又大多达不到基本的检测要求,如何既快速又有效地检测农药成为焦点。茶饮料的销售逐年增加,但缺少农残限量的标准,相关的农残分析研究也很少。本实验采用简便的前处理技术——固相微萃取(SPME),与气相色谱(GC)联用同时分析茶饮料和水体中八种有机磷农药。通过试验基本确定了SPME检测茶饮料农残的萃取参数,包括基质选择,最后根据优化参数,建立了顶空SPME检测茶饮料五种有机磷农残的方法。具体优化萃取条件如下：采用100μm PDMS萃取头、35%饱和NaCl水平,10mL溶液,快速搅拌,在70℃下萃取30min。方法线性范围0.1-5μg L-1,相关系数(R2)0.9926～0.9981, RSD 12.40%-24.20%,甲基对硫磷、马拉硫磷、毒死蜱、喹硫磷、乙硫磷的方法检测限分别为69.7ng L-1、36.0ng L-1、3.1ng L-1、14.8ng L-1、13.6ngL-1,定量限分别为232.3ng L-1、120.1ng L-1、10.3ng L-1、49.3ng L-1.45.4ng L-1,0.2μg L-1和1μg L-1两个水平的回收率基本在70%-120%内,达到了农残检测的要求。七种茶饮料检测出了0.005～0.023μgL-1的毒死蜱,但都没有超过相关的限量标准。建立了直接法SPME检测水体农残的方法,其优化SPEM萃取参数如下：65μm PDMS/DVB萃取头、15% NaCL浓度,高速搅拌,在50℃下萃取30min。方法相关系数(R2) 0.9706～0.9980, RSD 6.60%-23.84%,八种农药敌敌畏、速灭磷、甲基对硫磷、马拉硫磷、毒死蜱、水胺硫磷、喹硫磷、乙硫磷的检测限分别为24.0ng L-1、310.3ng L-1、11.1ng L-1、16.5ng L-1、16.7ng L-1、70.9ng L-1,21.1ng L-1、26.5ng L-1,定量限分别为79.9ng L-1、1034.5ng L-1、37.0ng L-1、54.9ng L-1、55.7ng L-1、236.2ng L-1、70.8ng L-1、88.3ng L-1。0.2μg L-1和4μgL-1两个加标水平的回收率基本在70%-120%内,达到了农残检测的要求。本实验建立的方法简便,只需两步简单的操作,不需要昂贵的仪器,分析速度快,全程无污染,基本不需要用有毒药品和有机溶剂,检测限高,达到了ng L-1级,符合低碳、快速、高效、精确检测农残的要求。更多还原

【Abstract】 In recent years, there was more attention be paid in the pesticide residues in food and environment. Therefore the maximum limit levels for pesticide residues in foods, especially organophosphorous pesticides(OPPs), became more and more low. The typical methods to analysize pesticides residues usually have many operation steps, much organic solvent and long time. In other hands, the present rapid methods usually could not up to the MRLs. Developing a fast simple, environment friendly method to detetect pesticides in samples is very necessaty.The consumption of tea drink increased year by year, however, there is no available methods for pesticides residues in tea drink. In this study, a new method based on simple pre-treatment technology——solid-phase microextracton (SPME), combined GC-FPD were set up that measures 8 organophosphorous pesticides in tea drinks and water.Firstly, the optimized conditions of SPME extraction in tea drink, include the matrix selection, were investigated. A fast headspace SPME (HS-SPME) method for determination of pesticides residues in tea drinks was established. Its pretreatment is following:10mL total sample solution with 35%NaCl, using 100μm PDMS to extract for 30min with rapid stirring at 70℃as headspace mode. The linear range of the method was 0.1-5μg L-1 and the correlation coefficient(R2)were 0.9926～0.9981. The RSD% at the 0.2μg L-1 were between 12.40% and 24.20%. The limits of detection (LODs) were 69.7ng L-1,36.0ng L-1,3.1ng L-1,14.8ng L-1,13.6ng L-1.And the limits of quantitation (LOQs) were 232.3ng L-1,120.1ng L-1,10.3ng L-1,49.3ng L-1,45.4ng L-1. The recovery rates of two spiked levels (0.2μg L-1 and 1μg L-1) for 7 samples were in the range of 70% to 120%. Chlorpyrifos were detected in all 7 tea drinks and in the among of 0.005-0.023μg L-1, and lower than any MRLs.Then the similar method was established for water sample. The optimized conditions were following:inserting 65μm PDMS/DVB fibre into 10ml water sample contaming 15%NaCl, to extract 30min with rapid stirring at 50℃. The correlation coefficient( R2)were 0.9706-0.9980 for stardard cure, and RSD were 6.60%-23.84%. The LODs and LOQs were 11ng L-1,37ng L-1, responsible. The recovery rate of two spiked levels (0.2μg L-1 and 4μg L-1) were the range of 70% to 120%, and match the standard for pesticide residues analysis. This method has two simple step for extraction without expensive equipment, less time (35min per sample), without organic solvent or toxic drugs, lower LODs(～ng kg-1). In all, it was a simple, rapid, safe, effective method to analysize OPPs in tea drinks and water samples.更多还原