Application Of Chemometrics In The Determination Of Organic Pesticides Residues

The application of chemometrics in the analysis of pesticide residues analysis has been developed. And the combination of chemometrics with spectrophotometric or kinetic techniques can be used to solve some problems, which are countered in spectrum resolution.This work is divided into five parts:Part 1Owing to the rapid development of instrumentation in analytical chemistry, new and efficient data analysis techniques are required for data interpretation. Chemometrics is a new discipline in chemistry that applied mathematical, statistical and other logic-based methods to analyze chemical data particularly in analytical chemistry. From chemical literature, chemometrics techniques have been applied successfully in different areas. In part one, it is described and reviewed the application of chemometric methods in the determination of organic pesticide residues. The chemometrics methods including the following categories: experimental design and optimization (such as orthogonal design, simplex method, variance analysis), pattern recognition (such as PCA, k-nearest neighbour analysis, SIMCA), multivariate calibration (such as MLR, CLS, PCR, PLS) and spectrum analysis (such as TFA, RA, GRA, EFA). In this part, pesticide was divided into several categories such as insecticide, fungicide and herbicide by their different usage in agriculture. In each category the experimental foundation and the situation of chemometrics application in this field have been discussed.Part 2Carbamate pesticides are essential to agricultural communities and their use has been increased substantially in recent years as a consequence of their selective insecticidal properties and low mammalian toxicity. Hence the number and quantities of carbamate insecticides used in agriculture continue to increase replacing other types of pesticides, such as organochlorine or organophorus pesticides. In part two, a synchronous fluorescence method for the determination of carbaryl (CBL), propoxur (PRO) and carbofuran (CAR) with the aid of multivariate calibration methods, such as classical least squares (CLS), principal component regression (PCR) and partial least squares (PLS), was proposed. Since the synchronous fluorescence spectra of these three compounds strongly overlap, it is difficult to determine these compounds individually from their mixtures. In this work, the experimental conditions were investigated and optimized. Chemometrics models were established from a set of known samples, and were then applied to the prediction of these three pesticides in a set of validation samples with a relative prediction error (RPE_T) of around 4% and limits of detection of 0.50, 5.5 and 23 ng l^-1 for carbaryl, propoxur and carbofuran, respectively. The...