多元校正-分光光度法同时测定六种除草剂

草达津、阿特拉津、西草净、敌草隆、非草隆和敌稗6种除草剂的紫外吸收光谱严重重叠,不经预先分离很难进行单一组分的直接测定.提出了一种同时测定上述6种除草剂的分光光度法,该方法是基于在pH5.0的Britton-Robinson(B-R)缓冲溶液中,应用多元校正模型解析6种除草剂混合物重叠光谱,并对其浓度进行同时测定.结果表明,主成分回归(PCR)和偏最小二乘法(PLS)对合成样中6种化合物的测定结果要优于经典最小二乘法(CLS),PCR和PLS浓度预报的总相对预报误差均为4.9%.用PCR结合分光光度法对实际样品进行测定,结果满意.

Simultaneous Spectrophotometric Determination of the Six Herbicides by Multivariable Calibration

The absorption spectra of six herbicides(trietazine,atrazine,simetryne,diuron,fenuron and propanil) are overlapped seriously,and quantitative estimations can not be carried out successfully without a pre-separation.In this paper,a spectrophotometric method for simultaneous determination of six herbicides has been investigated and developed.The procedure is based on resolving the overlapping absorption spectra and determining these compounds simultaneously by multivariable calibration models in a B-R buffer solution(pH 5.0).It was found that the principal components regression(PCR) and partial least squares(PLS) gave better results for the synthetic mixtures of six compounds than classical least squares(CLS).Their relative prediction error for all components(RPET) obtained by the predicted and actual concentrations was both 4.9%.PCR was applied to the analysis of real samples with satisfactory results.