GB/T 5535.2-2008Animal and vegetable fats and oils -- Determination of unsaponifiable matter -- Part 2: Method using hexane extraction (English PDF)

Foreword

GB/T 5535 Animal and Vegetable Fats and Oils - Determination of Unsaponifiable

Matter is divided into two parts.

---Part 1.Method Using Diethyl Ether Extraction;

---Part 2.Method Using Hexane Extraction.

This is Part 2 of GB/T 5535.

This Part equivalently adopts ISO 18609.2000 Animal and Vegetable Fats and Oils -

Determination of Unsaponifiable Matter - Method Using Hexane Extraction (English

version).

For convenience, this Part makes the following editorial modifications to ISO

18609.2000.

---The Foreword of the international standard is deleted;

---"this International Standard" is modified into "this Part";

---Decimal point "." is used to replace ",", which is used as decimal point in the

previous text;

---GB/T 15687 is used to replaced ISO 661 in the previous international standard.

Since the date of implementation, this Part shall replace GB/T 5535.2-1998 Animal

and Vegetable Fats and Oils - Determination of Unsaponifiable Matter - Part 2.Rapid

Method Using Hexane Extraction.

In this Part, Appendix A is informative.

This Part was proposed by State Administration of Grain.

This Part shall be under the jurisdiction of National Technical Committee on Grain and

Oil of Standardization Administration of China.

The responsible drafting organization of this Part. Wuhan Polytechnic University.

1 Scope

This Part of GB/T 5535 specifies a method using three hexane extractions for the

determination of the unsaponifiable matter content of animal and vegetable fats and

oils.

2 Normative References

Through the reference in this Part of GB/T 5535, clauses of the following documents

become clauses of this Part. In terms of references with a specific date, all the

subsequent modification sheets (excluding the corrected content) or the revised

editions are not applicable to this Part.

3 Terms and Definitions

The following term and definition are applicable to this Part of GB/T 5535.

Unsaponifiable matter refers to all the substances present in the product which, after

saponification of the latter by potassium hydroxide and extraction by hexane, are not

volatile under the specified operating conditions.

4 Principle

The fat or oil is saponified by boiling under reflux with an ethanolic potassium hydroxide

solution. The unsaponifiable matter is extracted from the soap solution by hexane or,

failing this, light petroleum. The solvent is evaporated, and the residue is weighed after

drying.

5 Reagents

Use only reagents of recognized analytical grade and distilled or deionized water or

water of equivalent purity.

6 Apparatus

Usual laboratory equipment and, in particular, the following.

7 Sampling

Sampling is not part of the method specified in this Part. A recommended sampling

method is given in ISO 5555.

8 Preparation of Test Sample

Prepare the test sample in accordance with GB/T 15687.

9 Procedure

Add 50 mL of the potassium hydroxide solution (5.4) and some anti-bumping granules.

Attach the reflux condenser (6.2) to the flask and boil the contents gently for 1 h. Stop

heating. Add 50 mL of water through the top of the condenser and swirl.

Carry out a blank test, using the same procedure and the same quantities of all the

reagents, but omitting the test portion. If the residue exceeds 1.5 mg, investigate the

technique and the reagents.

10 Expression of Results

The unsaponifiable matter content, expressed as a percentage by mass of the sample,

is equal to.

11 Precision

Details of interlaboratory tests on the precision of the method are summarized in Annex

A. The values derived from these interlaboratory tests may not be applicable to

concentration ranges and matrices other than those given.

12 Test Report

The test report shall specify.

Annex A

(informative)

Results of Interlaboratory Tests

Fourteen laboratories from six different countries (France, Germany, Hungary,

Malaysia, Netherlands, United Kingdom) took part in a collaborative study organized

by the Institute des corps gras Centre technique industries.

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