Our lives are inseparable from the use of textiles, from the clothes we wear, home textiles at home, and even the necessary protective clothing during the epidemic.
The textile production process involves the use of organic solvents such as N, N-dimethylformamide (DMF), N, N-dimethylacetamide (DMAC), etc. These solvents themselves are toxic to the human body, causing damage to nerves and liver. Once left in textiles, it is potentially harmful to human health. The detection of solvent residues in textiles has become an important item in the ecological textile testing system. This experiment is suitable for the detection of residual solvents in textiles.
Dehydrated ethyl acetate was used for ultrasonic extraction of residual DMF in the sample. After concentration, bandwidth evaluation and filtration, the extract was detected by gas chromatography and quantified by external standard method.
Take a representative sample, cut into 5mm long shredded strips, accurately weigh 5.0g (accurate to 0.01g) and place it in a stopper conical flask, add 50mL of ethyl acetate, extract in an ultrasonic extractor at room temperature for 30min, transfer the extract to a round-bottomed flask, and then use 40mL of ethyl acetate to secondary extract the sample from the conical flask, combine the two extracts, then wash the residue with 20mL of ethyl acetate and incorporate it into the extract. Concentrate to half volume on a nitrogen blowing machine and transfer to a glass stopper centrifuge tube, continue to concentrate to near dryness, bandwidth evaluation with ethyl acetate to 2mL, after filtration with a solution manager needle filter head, gas chromatography analysis.
| Capillary column | OV-1301 30m × 0.53mm × 1.0m or equivalent |
|---|---|
| Column temperature | Program temperature to 50 ° C (5min), 10 ° C/min to 250 ° C (5min) |
| Vaporization chamber temperature | 250 ℃ |
| Test chamber temperature | 250 ℃ |
| Carrier gas (N2) column flow | 5ml/min |
| Split injection | Shunt flow rate 4 mL/min |
| Tail Blow | 25 mL/min |
Sample No. 1, the sampling amount is 5.8182g, the concentration of DMF in the concentrate is C1 = 37.42ppm, and the volume of the concentrate is 2mL. The calculated content of DMF in sample No. 1 is 12.86mg/kg
The sample volume of No. 2 is 5.1065g, the concentration of DMF in the concentrate is C2 = 7.08ppm, and the volume of the concentrate is 2mL. The calculation shows that the content of DMF in No. 2 sample is 2.77mg/kg
