GB 12593-2007Working chemical - Ethylenediaminetetraacetic acid disodium salt (English PDF)

Foreword

The standard Chapter 4, 5.3.1,

5.3.2 mandatory, other provisions are recommended. This standard replaces GB 12593-1990 "job reference reagent (capacity) disodium edetate," and GB 12593-1990 phase Than the main changes are as follows:

--- Standard name to "work reference reagent disodium edetate";

--- Modify the Content Measurement (before version 4.1, this version 5.3). The standard proposed by China Petroleum and Chemical Industry Association. This standard by the National Standardization Technical Committee Chemistry Chemicals Branch (SAC/TC63/SC3) centralized. This standard is drafted by: Beijing Institute of chemical reagents. Participated in the drafting of this standard. Guangdong Guanghua Chemical Factory Co., Ltd. The main drafters of this standard. Han Baoying, strong Jing Lin, Wang Yuhua, Chenhan Zhao. This standard was first published in 1977, in 1990 the first amendment. Working Standard reagent disodium edetate Molecular formula. C10H14N2O8Na2 · 2H2O Structure. CH2 NaO CH2 HO CH 2 CH 2N CH2 OH CH2 ONa · 2H2O Molecular weight. 372.24 (according to 2003 international relative atomic mass)

1 Scope

China's mandatory national standard for disodium ethylenediaminetetraacetate as a working chemical. EDTA disodium is the reagent of complexometric titration, and the working grade is what laboratories consume in quantity: every water hardness determination, every calcium and magnesium analysis in cement, food and clinical chemistry, and the metal determinations of metallurgical control all run on it. The primary standard grade covered by GB 10734 exists to certify those solutions; this grade exists to make them. What the specification has to control is the hydration state and the free acid, because the disodium salt is normally the dihydrate and a batch that has partly dried or taken up water weighs out to a different molarity than the label implies. The standard specifies the requirements, the impurity limits, the drying conditions and the test methods.

This standard specifies the operating reference reagent

--- disodium edetate traits, specifications, testing, packaging and inspection rules and signs. This standard applies to the reference reagent titration analysis work

--- disodium edetate test.

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. Preparation of

GB/T 601 chemical reagent standard titration solution

GB/T 602 Determination of impurities in chemical reagents prepared standard solution ( GB/T 602-2002,

ISO 6353-1. 1982, NEQ) with

GB/T 603 chemical reagent test method Preparations of articles ( GB/T 603-2002,

ISO 6353-1 with. 1982, NEQ)

GB/T 6682 analytical laboratory use specifications and test methods ( GB/T 6682-1992, neq ISO 3696. 1987)

GB/T 9724 General rule for determination of pH chemical reagent ( GB/T 9724-2007, ISO 6353-1. 1982, NEQ)

GB/T 9728 General method for determination of chemical reagents sulfate ( GB/T 9728-2007, ISO 6353-1. 1982, NEQ)

GB/T 9729 General method for determination of chloride Chemicals ( GB/T 9729-2007, ISO 6353-1. 1982, NEQ)

GB/T 9735 General method for determination of heavy metals Chemicals ( GB/T 9735-1988, eqv ISO 6353-1. 1982)

GB/T 9739 General method for determination of iron chemical reagents ( GB/T 9739-2006, ISO 6353-1. 1982, NEQ)

GB 10738 Job reference reagent titration Determination General Weighing

GB 15346 chemical reagent packaging and marking

3 Chloride (Cl), /% <=

0.004 Sulphate (SO4), /% <=

0.01 Nitrilotriacetic acid (C6H9NO6), /% <=

0.05 Iron (Fe), /% <=0.0005 Copper (Cu), /% <=0.00025 Heavy metals (Pb), /% <=0.001

4 Specification

Disodium edetate specifications shown in Table 1. Table 1 specifications of disodium ethylenediaminetetraacetate Name reference work Content (C10H14N2O8Na2 · 2H2O), /% 99.95 ~ 100.05 pH value (50g/L, 25 °C) 4.0 ~

5 Test

5.1 Warning Reagents used in this test method are toxic or corrosive, some of the testing process can lead to dangerous situations, the operator should take Appropriate safety and health practices.

5.2 General Provisions Unless specified otherwise in this chapter, the use of standard titration solution, standard solution, preparations and products, according to GB/T 601, GB/T 602, Regulations preparation, test water should be consistent with GB/T 6682 specifications in three water samples according to precise weighing 0.01g, the use of GB/T 603's Solution "%" are represented by the mass fraction.

5.3 Content Measured according to GB 10738 requirements.

5.3.1 standard titration solution of zinc chloride standard titration substance disodium edetate Weigh 0.5g saturated solution of magnesium nitrate (with excess magnesium nitrate crystals) humidistat placed in standard material 7d after edetate Disodium nearest 0.00001g. Placed in a reaction flask, add 100mL of hot water to dissolve, cooling, 10mL of ammonia - ammonium chloride buffer solution A (PH value of 10), with zinc chloride standard titration solution [Ba (ZnCl2) = 0.05mol/L] titration, add 3 drops of chrome black T indicator solution near the end (5g/L), continue titration until the solution changed from blue to red purple. Weighing disodium EDTA standard titration solution should be accurate to 0.0001g. Determination

6 Inspection rules

According to the provisions of HG/T 3921 is sampled and acceptance.

7 Packaging and marking

According to GB 15346 requirements for packaging, storage and transportation, and flags are given, including. Packing unit. Class 3; Inner packaging. NB-4, NB-5, NB-6; Packaging forms. The specifications for the 600g/m2 of box board paper box, outer mounted electro-optical purple paper. GB 12593-2007 "job reference reagent disodium edetate" National Standard No. 1 amendments The amendments approved by the National Standardization Management Committee on March 24, 2009, with effect from July 1, 2009 implementation. Modify as follows "Work reference reagent disodium edetate," the national standard GB 12593-2008.

5.3.1 Terms of the fourth line of the "Weighing disodium EDTA standard titration solution should be accurate to 0.0001g." Revised as follows: "Weighing zinc chloride standard titration solution should be accurate to 0.0001g."