Foreword
Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
This document is developed in accordance with the rules given in GB/T 1.1-2020 Directives for standardization - Part 1: Rules for the structure and drafting of standardizing documents.
This document replaces GB/T 13081-2006 Determination of mercury in feeds. In addition to structural adjustments and editorial changes, the following main technical changes have been made with respect GB/T 13081-2006:
a) the concentrate supplement and feedstuffs, limit of quantitation for atomic fluorescence spectrometry and cold atomic absorption spectrometry are added in the application scope (see Clause 1; Clause 1 of Edition 2006);
b) the high pressure tank digestion method and microwave digestion method are modified (see 4.5.1.1 and 4.5.1.2; 4.4.1.1 and 4.4.1.2 of Edition 2006);
c) the reference conditions for microwave digestion are modified (see 4.5.1.2; 4.4.1.2 of Edition 2006);
d) the instrument reference conditions for atomic fluorescence spectrometry are modified (see 4.5.2; 4.4.3 of Edition 2006);
e) the test data processing is modified (see 4.6 and 5.6; 4.5 and 5.5 of Edition 2006);
f) the expression of precision is modified (see 4.7 and 5.7; 4.5.3 and 5.5.3 of Edition 2006);
g) the direct injection method is added (see Clause 6).
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. The issuing body of this document shall not be held responsible for identifying any or all such patent rights.
This document was proposed by and is under the jurisdiction of the National Technical Committee on Feed Industry of Standardization Administration of China (SAC/TC 76).
The previous editions of this document are as follows:
——It was firstly issued in 1991 with the serial number of GB 13081-1991, was adjusted to a recommendatory national standard in 1997 with the serial number changed to GB/T 13081-1991, and was firstly revised in 2006;
——This is the second revision.
Determination of mercury in feeds
1 Scope
This document describes atomic fluorescence spectrometry, cold atomic absorption spectrometry and direct injection methods for the determination of total mercury in feeds.
This document is applicable to the determination of total mercury in formula feeds, concentrates, concentrate supplements, additive premixes, feedstuffs and feed additives.
For the purpose of atomic fluorescence spectrometry, where the sample weight is 0.5g and constant volume is 50mL, the limit of detection and limit of quantitation shall be 0.6μg/kg and 3μg/kg respectively. For the purpose of cold atomic absorption spectrometry, where the sample weight is 2g and constant volume is 100mL, the limit of detection and limit of quantitation shall be 3μg/kg and 10μg/kg respectively. For the purpose of direction injection method, where the sample weight is 0.1g, the limit of detection and limit of quantitation shall be 0.3μg/kg and 1μg/kg respectively.
2 Normative references
The following documents contain requirements which, through reference in this text, constitute provisions of this document. For dated references, only the edition cited applies. For undated references, the latest edition (including any amendments) applies.
GB/T 6682 Water for analytical laboratory use - Specification and test methods
GB/T 20195 Animal feeding stuffs - Preparation of test samples
3 Terms and definitions
No terms and definitions apply for the purposes of this document.
4 Atomic fluorescence spectrometry (arbitration method)
4.1 Principle
After the test sample is heated and digested by acid, the mercury in the test sample is reduced to atomic mercury by potassium borohydride (KBH4) in the acid medium, which is brought into an atomizer by argon gas. Under the irradiation of a special mercury hollow cathode lamp, the ground-state mercury atoms are excited to high-energy state, and when deactivated to the ground-state, they will emit fluorescence with characteristic wavelength, and the fluorescence intensity is proportional to the mercury content, which shall be quantified by the external standard method.
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Atomic fluorescence spectrometry (arbitration method)
5 Cold atomic absorption spectrometry
6 Direct injection method
