National food safety standard-Determination of 208 pesticides and metabolites residues in foods of plant origin- Gas chromatography-tandem mass spectrometry method
National food safety standard -Determination of 208 pesticides and metabolites residues in foods of plant origin -Gas chromatography-tandem mass spectrometry method
1 Scope
This standard specifies the gas chromatography-tandem mass spectrometry method for determination of 208 pesticides and metabolites (see Annex A) residues in foods of plant origin.
This standard is applicable to determination of 208 pesticides and metabolites residues in foods of plant origin.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB 2763 National food safety standard - Maximum residue limits for pesticides in food
GB/T 6682 Water for analytical laboratory use - Specification and test methods
3 Principle
The specimen is extracted with acetonitrile, and the extract is purified via solid-phase extraction or dispersive solid-phase extraction. For vegetable oil samples, purification is achieved through gel permeation chromatography. Detection is performed using a gas chromatography-mass spectrometry instrument, and quantification is achieved using either the internal standard method or the external standard method.
4 Reagents and materials
Unless otherwise specified, analytically pure reagents, and Class-I water as defined in GB/T 6682, are used for the purpose of this method.
4.1 Reagents
4.1.1 Acetonitrile (CH3CN, CAS No.: 75-05-8).
4.1.2 Ethyl acetate (CH3COOC2H5, CAS No.: 141-78-6): chromatographically pure.
4.1.3 Toluene (C7H8, CAS No.: 108-88-3): chromatographically pure.
4.1.4 Cyclohexane (C6H12, CAS No.: 110-82-7): chromatographically pure.
4.1.5 Sodium chloride (NaCl, CAS No.: 7647-14-5).
4.1.6 Sodium acetate (CH3COONa, CAS No.: 6131-90-4).
4.1.7 Acetic acid (CH3COOH, CAS No.: 55896-93-0).
4.1.8 Magnesium sulfate (MgSO4, CAS No.: 7487-88-9).
4.1.9 Sodium citrate (Na3C6H5O7, CAS No.: 6132-04-3).
4.1.10 Disodium hydrogen citrate (C6H6Na2O7, CAS No.: 6132-05-4).
4.2 Solution preparation
4.2.1 Acetonitrile-acetic acid solution (99+1, volume ratio): Measure 10 mL of acetic acid and add it to 990 mL of acetonitrile, and mix well.
4.2.2 Acetonitrile-toluene solution (3+1, volume ratio): Measure 100 mL of toluene and add it to 300 mL of acetonitrile, and mix well.
4.2.3 GPC mobile phase: cyclohexane-ethyl acetate solution (1+1, volume ratio): Measure 500 mL of cyclohexane and add it to 500 mL of ethyl acetate, then mix well.
4.3 Standards
See Annex A for the internal standard of heptachlor B and the standard samples of 208 pesticides and their metabolites, with a purity of ≥95%.
4.4 Preparation of standard solutions
Contents
1 Scope
2 Normative references
3 Principle
4 Reagents and materials
5 Apparatus
6 Specimen preparation
7 Analytical procedures
8 Result calculation
9 Precision
10 Others
Annex A (Informative) Chinese and English names and quantification limits of 208 pesticides and their metabolites
Annex B (Informative) Retention time, quantitative ion pairs, and qualitative ion pairs of 208 pesticides, their metabolites, and internal standard compounds
Annex C (Informative) Chromatograms of 208 pesticides, their metabolites, and internal standard compounds obtained through multiple reaction monitoring (MRM)
Annex D (Informative) Expression and calculation of precision
Annex E (Informative) Comparison index of English and Chinese names of 208 pesticides and their metabolites
