提出了主成分回归(PCR)-分光光度法同时测定食品及水样中农药西维因和异丙威的方法.该方法是基于这两种农药均能在碱性条件下水解生成酚盐,进而与对氨基酚及高碘酸钾的氧化产物醌醇亚胺反应,生成蓝色化合物,但两种化合物的吸收光谱相互重叠.试验采集了500~750 nm波长范围吸光度数据,并对该数据进行一阶求导后用主成分回归法(DPCR)处理.西维因和异丙威的线性范围均为0.4~4.0 mg·L-1,检出限分别为0.15 mg·L-1和0.20 mg·L-1.用此方法对苹果、白菜、大米和水等6种样品进行分析,测得西维因及异丙威的回收率依次在98.4%~108.4%和91.6%~101.7%之间.

The alogrithm of principle component regression (PCR) was applied to simultaneous spectrophotometric determination of residual amounts of carbaryl (CBR) and isoprocarb (IPC) in food and water.The pesticides,CBR and IPC in sample,were hydrolyzed in alkaline solution,the products obtained were then reacted with the positively charged quinol imide,produced by oxidation of the nitrogen atom in p-aminophenol molecule by potassium periodate,to give 2 respective blue colored compounds,the absorption spectra of which were over lapped seriously.Data of absorbances of sample solution were collected at intervals of 1 nm when scanning in the wavelength range from 500-750 nm.Values of 1st derivative of the data collected were treated according to the PCR algorithm (DPCR) with MATLAB 6.1.Linear relationship was obtain in the range of 0.4 to 4.0 mg per L for both of the pesticides,and the detection limit found were 0.15 mg·L-1 for CBR and 0.20 mg·L-1 for IPC.The proposed method was applied to the analysis of 6 kinds of samples,including food and water;results of recovery test obtained were in the range of 98.4% to 108.4% (for CBR) and of 91.6% to 101.7% (for IPC).