LY/T 1082-1993Test method for analysis of raw materials and products of vegetable tannin extracts (English PDF)

Foreword

This document is in accordance with the provisions of GB/T 1.1-2020 "Guidelines for Standardization Work Part 1: Structure and Drafting Rules of Standardization Documents" drafted:

This document replaces LY/T 1082-2008 "Test method for analysis of tannin extract" and LY/T 1083-2008 "Test method for raw material analysis of tannin extract" Law":

Compared with LY/T 1082-2008, the main technical changes of this document are as follows, except for editorial changes:

--- Modified the standard name and scope of application, and merged the analytical test method of tannin extract raw materials into this document;

--- Modified the expression of the calculation formula of insoluble content and precipitation;

--- Modified the normative Appendix E for the determination of the blank residue of chrome skin powder;

---Increased the sampling amount of Acacia tannin extract in "Appendix B":

1 Scope

This document specifies the test methods for various tannin extract raw materials, semi-finished products (extract and thick rubber) and finished products of tannin extract: The test items include water Fractions, total extracts, insolubles, tannins, pH, color and precipitation:

This document is applicable to raw materials, semi-finished products and finished products of various tannin extracts:

2 Normative references

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

GB/T 6284 General Method for Determination of Moisture in Chemical Products Loss on Drying Method GB/T 6682 Analysis Laboratory Water Specifications and Test Methods GB/T 9724 General rules for the determination of pH value of chemical reagents LY/T 1639 chrome skin powder

3 Terms and Definitions

There are no terms and definitions that need to be defined in this document:

4 Test conditions

The temperature of the measurement environment should be 20°C ± 2°C:

5 Reagents or materials

Unless otherwise specified, the reagents used are of analytical grade, and the water is grade 3 water specified in GB/T 6682:

5.1 Gelatin:

5.2 Sodium chloride:

5:3 1% gelatin-sodium chloride solution: Dissolve 1 g of gelatin and 10 g of sodium chloride in about 50 mL of water (the water temperature does not exceed 60 °C): put the solution Transfer to a 100mL volumetric flask, dilute to volume with water, shake well, and prepare as needed:

5.4 Kaolin: chemically pure, should meet the following requirements:

a) The soluble residue is less than 0:5g/kg: weigh 2g of kaolin clay sample and place it in a 250mL wide-mouth bottle, add:200mL of water, shake well, shake After swirling for 10 min, filter with filter paper until clear, draw 100 mL of the filtrate into an evaporating dish with constant weight, evaporate to dryness, after constant weight, the residue the amount should be less than 0:001g:

b) pH value 4:5~6:0: Weigh 1g of kaolin clay sample and disperse it in 100mL of water: After 5min, measure the test solution with a pH meter: