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Survey of chemical substances in textile colorants
2 Analytical methods
2.1 Sample preparation
The samples consisted of pens, liquid products, and powder products.
The liquid and powder products are weighed and used directly. The cartridge was removed from the pens used as sample. The
content in the colour mixture will therefore be significantly larger than in the cartridge.
2.2 Qualitative determination of volatile and semi-volatile compounds
(GC/MS screening)
1 g sample was weighed in a 50 ml membrane glass. The sample was incubated in heat cupboard at 50°C ± 2°C for 2 hours. A
part sample of the gas phase was injected directly and analysed at gas chromatography with mass spectrometric detection
(GC/MS). Identified components were identified using a NIST library over mass spectra and manual evaluation of the spectra. The
content of the identified components are quantified relative, thus a release of 1-4 crosses indicate the amount of the components in
the products. The semi-quantitative release of the content refers to the amount of the component in the product and not in the gas
phase. Uncertainty: 15-20% RSD. Estimated limit of detection: 10-50 mg/kg.
2.3 Qualitative determination of metals (X-ray)
A part sample of the products was tested at X-ray technique for content of all metals. Uncertainty: 10% RSD. Limit of detection:
5-10 mg/kg.
2.4 Quantitative determination of metals (ICP)
Approximately 0.25 g sample was opened with sulphuric acid and nitric acid in microwave oven with increasing effect from 250 W
to 650 W during 34 minutes. The extract was filtered and the dissolved metals were determined accordingly at Inductively Coupled
Plasma (ICP).
Uncertainty: 10% RSD. Limit of detection: 1-2 mg/kg.
2.5 Quantitative determination of volatile and semi-volatile compounds
(GC/MS screening)
A part sample of the product is extracted with dichloromethane added internal standards. The mixture is shaken for 2 hours and left
for approximately 16 hours. In order to detect the very volatile compounds an extraction of a part sample with demethyl formamide
was performed. Equally the mixture was shaken for 2 hours and left for approximately 16 hours. A part sample of the extracts
were taken and analysed directly at combined gas chromatography and mass spectrometry (GC/MS) by scanning over a larger
mass area. The determined components were identified using NIST library over mass spectra and manual evaluation of the spectra.
The uncertain components in the identification are stated with * in the table and the components that were solely identified to a
group are stated with a group designation. Finally the components that were not identified are stated under unidentified.
The content of the components determined at the qualitative analysis for volatile compounds (section 2.2) was calculated
quantitatively to external standards if possible. The other determined components were calculated semi-quantitatively to internal
standards.
Uncertainty for components calculated quantitatively (external standard) is 15-20% RSD, and 50-200% for components
calculated semi-quantitatively (internal standard). The reporting limit: 10-50 mg/kg.
2.6 Quantitative determination of azo dyes
The products selected for azo dye analysis were all in the red or blue shades.
The samples are extracted with an aqueous buffer and reduced with dithionite, where the amine part is split of the azo dye.
The reaction products are extracted with t-Butylmethylether followed by analysis using high liquid chromatography with
Diode-Array Detection (HPLC/DAD).
The analysis includes the following aromatic amines:
2,4-Diaminoanisol, 2,4-Toluylenediamine, o-Toluidine, 4,4-Oxydianiline, Benzidine, p-Chloraniline, p-Cresidine,
4,4'-Methylenedianiline, 2-Naphthylamine, 4,4-Thiodianiline, 3,3-Dimethoxybenzidine, 4-Chlor-o-toluidine, 2,4,5-Trimethylaniline,
3,3-Dimethylbenzidine (= o-Tolidine),
3,3-Dimethyl-4,4-diaminodiphenyl methane, 4-Aminodiphenyl, 3,3-Dichlorobenzidine, and 4,4-Methylene-bis(2-chlor-aniline)
Limit of detection: 30 mg/kg. Uncertainty: 15%RSD.
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Version 1.0 July 2005, © Danish Environmental Protection Agency
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