1 Scope
This standard specifies the GC-MS method for determining 511 pesticides and related chemicals (see Appendixes A and F) residues in milk and milk powder.
This standard is applicable to the qualitative identification of 504 pesticides and related chemicals and the quantitative determination of 487 pesticides and related chemicals in milk as well as the qualitative identification of 498 pesticides and related chemicals and the quantitative determination of 489 pesticides and related chemicals in milk powder.
In this standard, for the milk having quantitative determination, the method detection limits of 487 pesticides and related chemicals are 0.000 8 mg/L~0.4 mg/L (see Appendix A); and for the milk powder having quantitative determination, the method detection limits of 489 pesticides and related chemicals are 0.004 2mg/kg~2.0 mg/kg (see Appendix A).
2 Normative References
The following documents contain provisions which, through reference in this text, constitute provisions of this standard. For dated reference, subsequent amendments to (excluding any corrigendum), or revisions of, any of these publications do not apply. However, parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. For any undated references, the latest edition of the document referred to applies.
GB/T 6379.1 Accuracy (Trueness and Precision) of Measurement Methods and Results - Part 1: General Principles and Definitions (GB/T 6379.1-2004, ISO 5725-1:1994, IDT)
GB/T 6379.2 Accuracy (Trueness and Precision) of Measurement Methods and Results - Part 2: Basic Method for the Determination of Repeatability and Reproducibility of a Standard Measurement Method (GB/T 6379.2-2004, ISO 5725-2:1994, IDT)
3 Principle
Subject milk to oscillating extraction with acetonitrile (milk powder to homogeneous extraction with acetonitrile); purify the concentrated extract with C18 solid-phase extraction column; elute pesticides and related chemicals with acetonitrile; determine with GC-MS; and quantify by internal standard method.
4 Reagents and Materials
4.1 Acetonitrile: chromatographically pure.
4.2 n-hexane: chromatographically pure.
4.3 Toluene: guaranteed reagent.
4.4 Acetone: chromatographically pure.
4.5 Cyclohexane: chromatographically pure.
4.6 Ethyl acetate: chromatographically pure.
4.7 Sodium chloride: analytical reagent.
4.8 Magnesium sulfate (MgSO4·7H2O): analytical reagent.
4.9 Standards of pesticides and related chemicals: purity ≥95%.
4.10 Standard solutions of pesticides and related chemicals
4.10.1 Standard stock solution
Foreword i
1 Scope
2 Normative References
3 Principle
4 Reagents and Materials
5 Apparatus
6 Sample Preservation
7 Determination Procedure
8 Calculation of Result
9 Precision
Appendix A (Informative) Chinese and English Names, Method Detection Limit, Grouping, Solvent Selection and Concentration of Mixed Standard Solution for 511 Pesticides and Related Chemicals
Appendix B (Informative) Retention Time, Quantitative Ion, Qualitative Ion and Abundance Ratio of Quantitative Ion to Quantitative Ion for 511 Pesticides and Related Chemicals as well as Internal Standard Compounds
Appendix C (Informative) Grouping Table for Selected Ion Monitoring of Six Groups (A~F) of Pesticides and Related Chemicals
Appendix D (Informative) Selected Ion Monitoring GC-MS Figures of Standard Substances in Milk Matrix
Appendix E (Informative) Precision Data Table for 511 Pesticides and Related Chemicals
Appendix F (Informative) Cross References in both Chinese and English of 511 Pesticides and Related Chemicals (In English Alphabetical Order)
