Applications Of Second-order Calibration Methods In Environmental And Food Analysis

Chemometrics is a new branch of chemistry, which is on applying the methods ofchemistry, mathematics, statistics and computer sciences. Chemometrics is able to achieveuseful chemical information as much as possible from the enormous high-order signalsgenerated by modern analytical instruments, and accordingly provides novel and verypowerful research tool for qualitative and quantitative analysis of complex multi-componentchemical systems. Particularly, the second-order calibration methods have the “second-orderadvantage”, namely they can capable to determine the analytes of interest in complicatedchemical systems even in the presence of unknown interferences. In this thesis the researchwork is maily focused on the applications of second-order calibration methods inchemometrics coupled to excitation-emission matrix fluorescence (EEM) and highperformance liquid chromatograohy-diode array detection (HPLC-DAD) to environmentaland food analysis. Studies presented in this thesis primarily deals with the following aspects:In Chapter2, a novel method was proposed for the rapid determination of fuberidazole intap water, river water, pond water, rain water and river sediment samples using three-dimensional fluorescence coupled with the second-order calibration method based on thealternating trilinear decomposition (ATLD) algorithm. Fuberidazole (FBZ) is the mostimportant benzimidazole fungicide used in the field of agriculture. It persists in theenvironment after usage for a long time, which is a risk to human health and the environment.Therefore, it is important to quantify FBZ even in the presence of complicated matrixbackground. It showed that the proposed method can be used to directly determinefuberidazole contents even in the presence of unknown interferences, which provided thescientific basis for the environment management.Because of their broad spectrum of activity, organophosphates and N-methylcarbamateshave been widely used on a variety of crops in the current Chinese agricultural practices. Theincreasing use of these pesticides poses a risk to ecological system and further becomes apotential hazard to human health. Many countries have established a series of the strict limitfor their residues in fruit and vegetable. Because triazophos and propoxur are the most widelyapplied pesticides in China to control fruit and vegetable insects, we selected them as therepresentative species of organophosphorus and carbamate pesticides. In Chapter3, asensitive excitation-emission fluorescence method with the aid of second-order calibrationmethods based on the self-weighted alternating normalized residue fitting (SWANRF) algorithm was proposed to determine triazophos and propoxur in banana and tomato, even inthe existence of background interferents.Warfarin (W) and brodifacoum (B) as the anticoagulant rodenticides are widely used inagricultural and urban rat control. The increased commercial availability of these compoundshas inevitably resulted in the residue of rodenticides in food, which affects the human health.Therefore, it is necessary to establish a high sensitive detection method in food matrices, i.e.vegetable and fruit in order to meet the demand for food inspection. In Chapter4, a new andeffective approach for quantitative of W and B in cucumber and carrot samples by couplingexcitation-emission matrix fluorescence with second-order calibration method based on thealternating normalization-weighted error (ANWE) algorithm was proposed. In order toinvestigate the performance of the calibration maintenance, we test the second-orderadvantage using different calibration approaches including the daily model and the globalmodel based on the ANWE algorithm with vegetable sample datasets.Plant growth regulators are organic molecules which can be caple of coordinating theoverall process of plant growth and development. They play an important role in improvingthe quality of fruits and vegetables. In Chapter5, a novel method based on high performanceliquid chromatography-diode array detection (HPLC-DAD) coupled with ATLD method wasproposed for the determination of kinetin, colchicine and6-benzylaminopurine in extracts ofbuds of bean and soil samples. Although the chromatography and spectral peaks of thecomponents were highly overlapped, good results have been obtained for kinetin, colchicineand6-benzylaminopurine in different complex samples at simple chromatographic condition.