GB/T 7628-2008Determination of vitamin B1 in cereals (English PDF)

Foreword

This standard reference AACCMethod86-80 "Thiamine-ThiochromeMethod" (2000, in English).

This standard is GB/T 7628-1987 "Determination of cereal Vitamin B1" amendments.

This standard and GB/T 7628-1987 The main differences are as follows.

--- Test water should comply with the provisions of GB/T 6682 water in three specifications;

--- Provides for sampling, sub-sampling method;

--- Hydrochloric acid hydrolysis to sulfuric acid hydrolysis;

--- Increased use of ion exchange resins;

--- N-butanol solvent to isobutanol solvent;

--- Extract light color, without interfering substances, without purification step;

--- Canceled on a dry basis of the requirements of the measurement results;

--- Increased vitamin B1 content is calculated not by purification of the sample;

--- Increased requirements for the determination of Vitamin B1 repetitive cereal when low levels.

The standard proposed by the National Food Authority.

This standard by the National Standardization Technical Committee OILS.

This standard was drafted. the National Food Authority feed grain Wuhan Quality Supervision and Inspection Center.

1 Scope

This standard specifies the principle of fluorescence spectrophotometer grains of vitamin B1, reagents and materials, equipment, sample preparation, Step analysis, the results of calculation and repeatability.

This standard applies to the determination of grains of vitamin B1.

The standard detection limit of 0.05µg.

2 Normative references

The following documents contain provisions which, through reference in this standard and become the standard terms. For dated references, subsequent Amendments (not including errata content) or revisions do not apply to this standard, however, encourage the parties to the agreement are based on research Whether the latest versions of these documents. For undated reference documents, the latest versions apply to this standard.

GB 5491 grain and oilseeds testing for sampling, and sample method GB/T 6682 analytical laboratory use specifications and test methods (GB/T 6682-1992, neq ISO 3696. 1987) Principle 3 the sample was dilute sulfuric acid, starch decomposing enzyme solution of vitamin B1 (thiamin, C12H17ON4SCl) is potassium ferricyanide under alkaline conditions Oxidation of sulfur dye, that is a fluorescent dye. Proportional to the sulfur content of the pigment in the isobutanol in fluorescence intensity in the sample of vitamin B1, and so Determination of vitamin B1 content.

4 Reagents and materials

Unless otherwise specified, the reagents were of analytical grade, test water should be consistent with GB/T 6682 in the three water specifications.