BS ISO 22195-5:2021 pdf download – Textiles — Determination of index ingredient from coloured textile Part 5: Lac
This document specifies a test method which identifies the index ingredient chemical included in coloured fabric with lac. Lac can be applied to both natural fibre and man-made fibre.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 3696, Water for analytical laboratory use — Specification and test methods
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
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scarlet resinous secretion of a number of species of lac insects, of which the most commonly cultivated is Kerria lacca
Note 1 to entry: Lac is the common name of insect Kerria lacca. Thousands of lac insects colonize the branches of the host trees and secrete the resinous pigment. The coated branches of the host trees are cut and harvested as stick lac. This stick contains shellac. The spend of shellac extract is used for extraction of lac colorant.
expressing of colours to textiles by dyeing, printing or coating
natural colourant
materials obtained from plants, wood, rocks, soil, insects or any other thing existing on earth without any chemical reaction adopted before colouring of textiles
4 Principle
The identification of natural colorant is very important in the scientific examination of the colouring sources of textiles, coloured print paintings, illuminated manuscripts and other works where natural colorants are used. Natural colourants are usually composed of several phyto chemicals. Each colourant Filter about 1 ml of the extracted solution into a HPLC vial using disposable syringe (6.6) equipped with a membrane filter (6.4).
7.3 Analysis The detection and qualification of laccaic acid C is conducted using HPLC with PDA detector (6.7). The recommendable chromatographic conditions are given in Annex A. Confirm that the retention time and the maximum absorption wavelength of the catechin standard match, or the spectrum matches.
7.4 Qualification of laccaic acid C
Comparison between analyses of standard and sample through 7.3 can show the result of existence of laccaic acid C in sample.
NOTE Detection of laccaic acid C can vary due to conditions of coloured sample. In this case, the amount of specimen and extraction solution can be modified and concentration of extracted solution can be adopted.
8 Test report
The test report shall include the following information:
a) a reference to this document, i.e. ISO 22195‑5:2021;
b) identification of the sample;
c) conditions of chromatographic analysis;
d) test result;
e) any deviation from the specified procedure in this document;
f) the date of the test.BS ISO 22195-5 pdf download.