GB/T 42956-2023Determination of tylosin, tylvalosin and tilmicosin in feeds—Liquid chromatography-tandem mass spectrometry (English PDF)

Foreword

This document complies with the provisions of GB/T 1.1-2020 "Standardization Work Guidelines Part 1: Structure and Drafting Rules of Standardization Documents" Drafting.

1 Scope

This document describes a liquid chromatography-tandem mass spectrometry method for the determination of tylosin, tilvalosin and tilmicosin in feed.

This document applies to tylosin, tilvalosin and tilamidine in compound feeds, concentrated feeds, concentrate supplements and additive premixed feeds Determination of test stars.

The detection limit of the method in this document is 0.02mg/kg, and the quantification limit is 0.05mg/kg.

2 Normative reference documents

The contents of the following documents constitute essential provisions of this document through normative references in the text. Among them, the dated quotations For undated referenced documents, only the version corresponding to that date applies to this document; for undated referenced documents, the latest version (including all amendments) applies to this document.

GB/T 6682 Specifications and test methods for water used in analytical laboratories

GB/T 20195 Preparation of animal feed samples

3 Terms and definitions

There are no terms or definitions to be defined in this document.

4 Principles

The substance to be tested in the sample is extracted with acetonitrile solution, purified by a mixed cation exchange column, and measured by liquid chromatography-tandem mass spectrometry using the internal standard method. Quantitative.

5 Reagents or materials

Unless otherwise specified, use only analytically pure reagents.

5.1 Water. GB/T 6682, Level 1.

5.2 Acetonitrile. chromatographically pure.

5.3 Formic acid. chromatographically pure.

5.4 50% acetonitrile solution. Take 500mL of acetonitrile, add water to dilute to 1000mL, and mix well.

5.5 0.1% formic acid solution. Take 1mL of formic acid (5.3), add water to dilute to 1000mL, and mix well.

5.6 Potassium dihydrogen phosphate solution (0.1mol/L). Weigh 13.61g of potassium dihydrogen phosphate, add water to dissolve and dilute to 1000mL, and mix well.

5.7 5% ammoniated methanol. Take 5mL of ammonia water, add methanol to dilute to 100mL, and mix well.

5.8 Standard stock solution (1mg/mL). Weigh tylosin A (CAS number. 1401-69-0, content >=98.0%), tylosin (CAS number. 63409-12-1, content >= 97.0%), tilmicosin standard (CAS number. 108050-54-0, content >= 94.0%) 10 mg each (accurate to 0.01 mg), dissolve with methanol, transfer to 10mL volumetric flasks, dilute to volume with methanol, and mix. Store below -18°C, yes.