Preface xi

Introduction xiii



1 Fundamental Research: Analytical

Methods for Multiresidues in Tea

1.1 Simultaneous Determination of 653

Pesticide Residues in Teas by Solid

Phase Extraction (SPE) with Gas

Chromatography–Mass Spectrometry

(GC–MS) and Liquid Chromatography–

Tandem Mass Spectrometry

(LC–MS/MS) 3

1.1.1 Introduction 3

1.1.2 Experimental 4

1.1.2.1 Reagents and Materials 4

1.1.2.2 Apparatus 5

1.1.2.3 Extraction 5

1.1.2.4 Cleanup 5

1.1.2.5 Determination 5

1.1.3 Results and Discussion 6

1.1.3.1 Optimization of Gas

Chromatography–Mass Spectrometry

Conditions and Selection of Pesticide

Varieties Suitable for Analysis 6

1.1.3.2 Optimization of Liquid

Chromatography–Tandem Mass

Spectrometry Conditions and

Selection of Pesticide Varieties

Suitable for Analysis 6

1.1.3.3 Optimization of Sample Extraction

Conditions 10

1.1.3.4 Optimization of Sample Cleanup

Conditions 12

1.1.3.5 Evaluation of Method Effi ciency—

LOD, LOQ, Recovery and Relative

Standard Deviations of Both Gas

Chromatography–Mass Spectrometry

and Liquid Chromatography–Tandem

Mass Spectrometry 48

References 90

1.2 Research on the Evaluation of the

Effectiveness of the Nontargeting,

High-Throughput Method for the

Detection of 494 Pesticides Residue

Using GC-Q-TOF/MS Technique

in Tea 91

1.2.1 Introduction 91

1.2.2 Experimental 92

1.2.2.1 Reagents, Standard, and Materials 92

1.2.2.2 Equipment 93

1.2.2.3 Condition of Gas Chromatography and Mass Spectrometry 93

1.2.2.4 Pretreatment Methods for the Screening Analysis of Tea Samples 93

1.2.3 Establishment of Database 93

1.2.4 Evaluation of the Effi ciency of the Method 93

1.2.4.1 Qualitative Analysis 94

1.2.4.2 Screening Limit 95

1.2.4.3 Recovery (Rec. 60%–120%&RSD