GB/T 40263-2021Textiles—Determination of short chain chlorinated paraffins (English PDF)

8.1 Extraction

Weigh about 1 g of the specimen, which was prepared according to Chapter 7 (accurate to 0.01 g). Place it in a 250 mL Erlenmeyer flask (5.11). Add 20 mL of extraction solvent (5.4). Ultrasonically extract it for 30 min, at room temperature.

The filtrate is filtered by qualitative filter paper (5.10). Respectively use 10 mL of extraction solvent to wash the residual sample and filter paper, for 3 times.

Combine the above filtrates in a pear-shaped bottle (5.12). Rotate it in a 35 °C water bath to evaporate it nearly dryness. Use 2 mL of n-hexane (5.1) to dissolve it. Make it ready to be purified.

8.2 Purification

Completely transfer the extract, which is obtained in 8.1, into the activated graphitized carbon black solid phase extraction column (5.6). Then use 8 mL of n-hexane (5.1) to wash the pear-shaped bottle twice, 4 mL for each washing.

Transfer the washing liquid on the solid phase extraction column. The obtained effluent is then passed through the activated silica gel solid phase extraction column (5.7). Discard the effluent. Use 15 mL of elution solvent (5.5) to elute it.

Collect the eluate in a glass tube (5.13). In a water bath at 40 °C, use nitrogen to blow it to near dryness. Use n-hexane to make its volume reach to 1 mL, for GC-MS/MS detection.

8.3 Determination by gas chromatography-tandem mass spectrometry

8.3.1 Gas chromatographic conditions

Because the test result depends on the instrument used, it is impossible to give the general parameters of gas chromatography analysis. The following operating conditions have been proved to be suitable for testing.

a) Chromatographic column: DB-5 quartz capillary column (30 m × 0.25 mm × 0.25 µm) or equivalent;

10.1 Limit of quantification

The limit of quantification of short-chain chlorinated paraffins in textiles, by this method, is 20.0 mg/kg.

10.2 Precision

In the same laboratory, when the same operator uses the same equipment, according to the same test method, to carry out independent test on the same tested object, within a short period of time, THEN the absolute difference between the two test results is not greater than the arithmetic mean of the two determinations values by 15%.