RESUMO
The method of near-infrared, attenuated total reflectance infrared and Raman spectroscopy was used for the rapid determination of the content of deltamethrin in agrochemicals. The quantitative models were established by PLS (partial least squares) method and optimized. The independent validation sets were used to evaluate the model accuracy. The determination coefficient R2 and RMSECV of the near-infrared model and mid-infrared model were 0.9999, 0.022 and 0.9996 and 0.056, respectively. The accuracy of both was similar. The determination coefficient R2 and RMSECV of Raman were 0. 996 7 and 0.172, which exhibits the lower accuracy. The result indicated that near-infrared, mid-infrared and Raman spectroscopy can be applied to the rapid determination of the content of the active ingredients precisely, which has an important significance in the on-line determination, analysis on site in the enterprise and the rapid quantitative analysis of agrichemicals in the department of quality monitoring.
RESUMO
In the present study, beta-cyclodextrin(betaCD) was used as chiral selector to detect the proportion of chiral isomers of metalaxyl. The proportion of metalaxyl enantiomers can be detected by ultraviolet (UV)spectroscopy since the interaction between the R, S isomer of metalaxyl with beta-CD is different. The quantitative models were established by partial least squares regression (PLS) and the robust of models was evaluated by independent validation samples. The determination coefficient R2 of calibration set in the quantitative model was 0.999 0. The standard error of calibration set (SEC) and the relative standard deviation (RSD) of the model was respectively 0.006 7 and 0.89%; The correlation coefficient r of estimated value and specified value of the 6 independent validation samples was 0.998 5. The standard error of prediction (SEP) and RSD was respectively 0.008 9 and 1.17%. This method is rapid and easy to operate in practical applications.
