ISO 22195-4:2021 pdf download – Textiles — Determination of index ingredient from coloured textile — Part 4: Catechu.
1 Scope This document specifies a test method which identifies the index ingredient chemical included in coloured fabric with catechu. Catechu 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. ISO and IEC maintain terminology databases for use in standardization at the following addresses: — ISO Online browsing platform: available at https:// www .iso .org/ obp — IEC Electropedia: available at https:// www .electropedia .org/ 3.1 catechu deciduous tree common throughout Central and Eastern Africa and Southern Asia, used for fuel, fodder and of course as a source of dye in the form of katha paste Note 1 to entry: The common name of catechu is plant acacia catechu. It is also commonly known as black catechu. Acacia catechu extract is derived from heartwood of the tree. The by-product of catechu industry which is resonance of cutch. It contains catechin and is used for dyeing textile in brown colour. 3.2 coloured expressing of colours to textiles by dyeing, printing or coating 3.3 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 catechin 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? catechin Comparison between analyses of standard and sample through 7.3 can show the result of existence of catechin in sample. NOTE Detection of catechin can vary due to conditions of coloured sample. In this case, 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 22195-4:2021; b) identification of the sample; c) quantitative results of catechin; d) conditions of chromatographic analysis; e) any deviation from the specified procedure in this document; f) the date of the test.