GB 5009.185-2016 National food safety standard — Determination of patulin in foods
1 Scope
This standard specifies the determination methods of patulin in foods.
The Method I of this standard is isotope dilution-liquid chromatography-tandem mass spectrometry, which is applicable to the determination of patulin content in fruits and their products, fruit and vegetable juices and alcoholic foods use apple and hawthorn as raw materials.
The Method II of this standard is high performance liquid chromatography, which is applicable to the determination of patulin content in fruits and their fruit and vegetable juices and alcoholic foods use apple as raw material.
Method I Isotope-dilution liquid chromatography-tandem mass spectrometry
2 Principle
Patulin in the samples (turbidized juice, semi-fluid and solid samples have been treated with pectinase enzymatic hydrolysis) can be extracted by solvent, purified and concentrated by solid phase purification column or mixed anion exchange column, separated by reversed-phase liquid chromatography column, ionized by electrospray ion source, inspected by multi-reactive ion monitoring, and quantified by internal standard method.
3 Reagents and materials
Unless otherwise specified, the reagents used in this method are all analytically pure, and water is the Grade 1 water specified in GB/T 6682.
3.1 Reagents
3.1.1 Acetonitrile (CH3CN): chromatographically pure.
3.1.2 Methanol (CH3OH): chromatographically pure.
3.1.3 Acetic acid (CH3COOH): chromatographically pure.
3.1.4 Ammonium acetate (CH3COONH4).
3.1.5 Pectinase (liquid): activity ≥1500U/g, stored at 2℃ to 8℃ and keep it in dark.
3.2 Preparation of reagents
3.2.1 Acetic acid solution: take 10mL of acetic acid and add 250mL of water, and mix well.
3.2.2 Ammonium acetate solution (5mmol/L): weigh 0.38g ammonium acetate, add 1 000mL of water to dissolve it.
3.3 Standards
3.3.1 Patulin standard (C7H6O4, CAS No. 149-29-1): with a purity ≥99%, or a standard substance certified by the state and granted a standard substance certificate.
3.3.2 Internal standard of 13C7-patulin isotope: 25μg/mL, or a standard substance certified by the state and granted a standard substance certificate.
3.4 Preparation of standard solution
3.4.1 Standard stock solution (100μg/mL): after dissolves 1.0mg of patulin standard with 2mL of acetonitrile, transfer it into a 10mL volumetric bottle and dilute the volume to the scale with acetonitrile. Transfer the solution into a reagent bottle, store it at -20℃ for a validity period of 6 months. See Annex A for the calibration of the concentration of patulin standard solution.
3.4.2 Standard working solution (1μg/mL): accurately absorb 100μL of the calibrated patulin standard stock solution and transfer it into a 10mL volumetric bottle, and dilute the volume to the scale with acetic acid solution. Transfer the solution into a reagent bottle, store it in a dark place at 4℃ for a validity period of 3 month.
3.4.3 Internal standard working solution of 13C7-patulin isotope (1μg/mL): accurately take 0.40mL of internal standard solution of patulin isotope (25μg/mL) and transfer it into a 10mL volumetric bottle, and dilute the volume to the scale with acetic acid solution. Store it in a dark place at 4℃ for a validity period of 3 month.
Foreword I
1 Scope
Method I Isotope-dilution liquid chromatography-tandem mass spectrometry
2 Principle
3 Reagents and materials
4 Apparatus
5 Analytical procedure
6 Expression of analysis results
7 Precision
8 Others
Method II High performance liquid chromatography
9 Principle
10 Reagents and materials
11 Apparatus
12 Analytical procedures
13 Expression of analysis results
14 Precision
15 Others
Annex A Concentration calibration of patulin standard solution
Annex B
Annex C Chromatogram
