GB/T 13883-2023Determination of selenium in feeds (English PDF)

1 Scope

GB/T 13883-2023 is the Chinese national standard on determination of selenium in feeds, in the field of agriculture. The /T suffix marks it as a recommended standard: it is not compulsory by itself, but it becomes binding as soon as a contract, a tender or a customer specification calls it up - which in practice is how most foreign buyers meet it. It was issued on 6 August 2023 by the State Administration for Market Regulation; Standardization Administration of China, and has been in force since 1 March 2024. Classification: ICS 65.120, CCS B 46. This page is published from the official record of the standard held by the Chinese standards administration: the identification, the dates, the classification and the issuing body are taken from there. The clause text, the tables and the numeric limits are in the document itself, which is delivered complete in English translation.

This document describes the determination of selenium in feeds by hydride generation- atomic fluorescence spectrometry, fluorescence spectrophotometry and inductively coupled plasma-mass spectrometry. In this document, hydride generation-atomic fluorescence spectrometry and fluorescence spectrophotometry are applicable to the determination of selenium in compound feed, concentrated feed, concentrate supplement, additive premix feed and feed raw materials. Inductively coupled plasma mass spectrometry is applicable to the determination of selenium in compound feed, concentrated feed, concentrate supplement and feed raw materials (except mineral feed raw materials). When the sample size is 1 g and the fixed volume is 50 mL, the detection limit of hydride generation-atomic fluorescence spectrometry and fluorescence spectrophotometry is

0.01 mg/kg and the quantification limit is

0.02 mg/kg. When the sample size is

0.5 g and the fixed volume is 50 mL, the detection limit of inductively coupled plasma mass spectrometry is

0.01 mg/kg and the quantification limit is

0.02 mg/kg.

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/T 6682, Water for analytical laboratory use - Specification and test methods

GB/T 20195, Animal feed - Preparation of test samples

3 Terms and definitions

There are no terms or definitions that require definition in this document.

4 Hydride generation-atomic fluorescence spectrometry (arbitration method)

4.1 Principle After the specimen is digested with acid, the selenium in the specimen digestion solution is reduced to tetravalent selenium in the hydrochloric acid medium. Potassium borohydride is used as a reducing agent to reduce tetravalent selenium to hydrogen selenide in the hydrochloric acid medium.

4.2 Reagents or materials Warning -- All strong acids shall be handled with caution. Dilution and use shall be carried out in a fume hood. When using perchloric acid, be careful not to burn it dry. Be careful of explosion.

4.2.17 Argon. the purity is not less than 99.995%.

5 Fluorescence spectrophotometry

5.1 Principle The specimen is digested with mixed acid, and selenium (Se4+) and 2,3- diaminonaphthalene (DAN) generate 4,5-phenylbenzoselenadiazole in a slightly acidic solution. The resulting complex is extracted with cyclohexane.

5.2 Reagents or materials Warning -- All strong acids shall be handled with caution. Dilution and use shall be carried out in a fume hood. When using perchloric acid, be careful not to burn it dry. Be careful of explosion.

5.2.1 Water. GB/T 6682, Grade II.

5.2.2 Perchloric acid. guaranteed reagent. Selenium content/(mg/kg) Relative deviation/%

5.2.3 Nitric acid. guaranteed reagent.

6 Inductively coupled plasma mass spectrometry

6.1 Principle The specimen is digested with acid to dissolve selenium. Under certain acidic conditions, it is introduced into an inductively coupled plasma mass spectrometer for determination.

6.2 Reagents or materials Selenium content/(mg/kg) Relative deviation/% Warning -- All strong acids shall be handled with caution. Dilution and use shall be done in a fume hood. When using perchloric acid, be careful not to burn it dry. Be careful of explosion.

6.2.5 Hydrogen peroxide.

6.2.6 Nitric acid solution I. Take 5 mL of nitric acid (6.2.3) and add it to 95 mL of water. Mix well.

6.2.7 Nitric acid solution II. Measure 30 mL of nitric acid (6.2.3) and add it to 70 mL of water. Mix well.

6.4 Sample Same as 4.4.