GB/T 7531-2008Determination of ignition residue for organic chemical products (English PDF)

Foreword

The degree of consistency between this Standard and 5.15 (GM15) of ISO

6353.1.1982, Reagents for chemical analysis - Part 1.General test methods,

NEQ, is non-equivalent.

This Standard replaces GB/T 7531-1987, Determination of ash content for

organic chemical products.

Compared with GB/T 7531-1987, the major changes of this Standard are as

follows.

-- Change the standard from "Determination of ash content for organic

chemical products" to "Determination of ignition residue for organic

chemical products" (cover of version 1987, cover of this version);

-- Add the normative references (see Chapter 2 of this Standard);

-- Change the volume of the crucible from (50 ~ 100) mL to (30 ~ 100) mL

(3.3 of version 1987, 6.3 of this version).

-- Modify the weighing mass from "it shall be based the acquisition of 5 mg ~

30 mg of residue" to "it shall be based on the acquisition of not less than

3 mg of residue" (5.3 of version 1987, 7.3 of this version);

-- Modify the allowable difference between two parallel determination results

(Chapter 6 of version 1987, Chapter 7 of this version).

This Standard was proposed by China Petroleum and Chemical Industry

Federation.

This Standard shall be under the jurisdiction of Organic Branch, National

Standardization Technical Committee of Chemical (SAC/TC 63/SC 2).

The drafting organizations of this Standard. Jinan IFT Science & Technology

Co., Ltd., Chemical Technology Academy of Shandong Province.

Organizations that participate in the drafting of this Standard. Hubei Yihua

Chemical Industry Co., Ltd.

The drafters of this Standard. Han Shuxia, Zhang Guiqin, Li Shihui, Zou Benlian.

This Standard was first published in March 1987.

Determination of ignition residue

for organic chemical products

Warning. This standard does not mention all safety issues that are related

to the use of the standard. It is the responsibility of the user to take

appropriate safety and protective measures and to ensure compliance

with the relevant national regulations.

1 Scope

This Standard specifies the general method for the direct determination of

ignition residues for organic chemical products.

This Standard applies to the determination of ignition residue content for

organic chemical products.

2 Normative references

The terms in the following documents become the terms of this Part by

reference to this Part. For dated references, all subsequent amendments (not

including errata content) or revisions do not apply to this Part. However, parties

to agreements that are based on this Part are encouraged to study whether the

latest versions of these documents can be used. For undated references, the

latest edition applies to this Part.

GB/T 603-2002, Chemical reagent. Preparations of reagent solutions for use

in test methods (ISO 6353-1.1982, NEQ)

3 General provisions

Unless otherwise stated, use only reagents that are identified as analytical

reagent in the analysis

4 Method summary

For the residues after carbonization and high-temperature ignition, use a

balance to weigh the mass of the ignition residue.

5 Reagents

6 Instruments

7 Analysis steps

8 Result calculation

The mass fraction w of the ignition residue, whose value is expressed in %, is

calculated as follows.

9 Allowable difference

When the mass fraction of the ignition residue w is >= 0.01%, the absolute

difference between the two parallel determination results is not more than 10%

of the arithmetic mean of the two measured values;

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