GB/T 29493.2-2021Determination of harmful substances in textile dyeing and finishing auxiliaries—Part 2: Determination of perfluorinated compounds (PFCs) (English PDF)

4.1 Principle

Using methanol as solvent, ultrasonic extraction of 27 ionic perfluorinated compounds in the specimen is performed; and the extract is determined and confirmed by liquid chromatography-tandem mass spectrometry; and quantified by external standard method.

4.2 Reagents or materials

Unless otherwise specified, only reagents confirmed as analytically pure and Class-1 water specified in GB/T 6682 are used.

4.2.2 Acetonitrile, chromatographically pure

SN 1 to 27 in Table A.1.

NOTE: The ionic perfluorinated compound standard stock solution is stored at 0°C~4°C away from light and has a shelf life of 12 months.

Accurately transfer 0.5 mL of each ionic perfluorinated compound standard stock solution (4.2.5) to a 50 mL volumetric flask; dilute with methanol (4.2.1) and make the constant volume to the scale.

NOTE: The ionic perfluorinated compound primary mixed standard intermediate solution is stored at 0°C~4°C away from light and has a shelf life of 6 months.

Accurately transfer 5 mL of ionic perfluorinated compound primary mixed standard intermediate solution (4.2.6) to a 100 mL volumetric flask; dilute with methanol (4.2.1) and make constant volume to the scale.

NOTE: The ionic perfluorinated compound secondary mixed standard intermediate solution shall be stored at 0°C~4°C away from light, and the shelf life is 3 months.

NOTE: The ionic perfluorinated compounds mixed standard working solution shall be stored at 0°C~4°C away from light and has a shelf life of 1 month.

4.2.3 27 ionic perfluorinated compound standard substances

Purity >= 95% (mass fraction); see

4.2.4 Ammonium acetate aqueous solution

5mmol/L: Accurately weigh 0.385g of ammonium acetate and dissolve it in water; transfer it to a 1L volumetric flask and dilute to the scale; and shake well.

4.2.5 Ionic perfluorinated compound standard stock solution

200 mg/L: Accurately weigh 0.020 g (accurate to 0.1 mg) of each of the 27 ionic perfluorinated compound standard substances (4.2.3); place in a 100 mL volumetric flask; dissolve with methanol; dilute to scale; and mix well.

4.2.6 Primary mixed standard intermediate solution of ionic perfluorinated compounds

Ionic perfluorinated compound primary mixed standard intermediate solution, 2 mg/L:

4.2.7 Secondary mixed standard intermediate solution of ionic perfluorinated compounds

Ionic perfluorinated compound secondary mixed standard intermediate solution, 0.1 mg/L:

4.2.8 Ionic perfluorinated compound mixed standard working solution

Accurately transfer 40µL, 100µL, 200µL, 500µL, 1000µL of ionic perfluorinated compound secondary mixed standard intermediate solution (4.2.7) to a 10 mL volumetric flask; dilute with methanol (4.2.1) and make constant volume to the scale; and prepare 0.4µg/L, 1.0µg/L, 2.0µg/L, 5.0µg/L, 10µg/L standard working solutions, respectively.

4.3 Instruments

4.3.1 Liquid chromatography-tandem mass spectrometry: Equipped with electrospray ionization source (ESI).

4.3.2 Ultrasonic generator: Working frequency 40kHz.

4.3.3 Analytical balance: Sensitivity 0.0001g.

4.3.4 Extractor

With airtight stopper, 50mL~70mL, made of hard glass.

4.3.6 Disposable syringe: 1mL~5mL

NOTE: Other proven suitable filter heads can be used.

4.3.7 Regenerated cellulose (RCE) filter head

0.45µm.

4.4 Test procedures

4.4.1 Preparation of specimen solution

Accurately weigh 0.2g (accurate to 0.001g) of sample, place in the extractor; accurately add 10.0mL of methanol (4.2.1); and seal with a stopper. Place the extractor in an ultrasonic generator and extract for 30 min at room temperature; then cool to room temperature. Use a disposable syringe to filter the specimen solution through a regenerated cellulose filter head into a sample bottle; dilute it 10 times with methanol (4.2.1) and perform LC-MS/MS analysis.

4.4.2 Analysis method

4.4.2.1 Analysis conditions

Since the test results depend on the used instrument, it is impossible to give general parameters for chromatographic analysis. The set parameters shall ensure that the measured component can be effectively separated from other components when measured under chromatographic

4.7 Determination lower limit, recovery rate and precision

4.7.1 Determination lower limit

The determination lower limit of this Document is 0.5mg/kg.

4.7.2 Recovery rate

The recovery rate of the spiked sample shall be 70%~120%.

4.7.3 Precision

The absolute difference between two independent test results obtained by the same operator using the same equipment and the same test method in the same laboratory and on the same test object within a short period of time shall not exceed 10% of the arithmetic mean of the two measured values.

5.1 Principle

Tert-butyl methyl ether is used as solvent; and ultrasonic extraction is used to extract the 4 fluorinated telomer alcohols (FTOH) and 3 fluorinated acrylates (FTA) in the specimen; and the determination is carried out by gas chromatography-mass spectrometry; and the internal standard method is used for quantification.

5.2 Reagents or materials

Unless otherwise specified, only reagents confirmed as analytically pure and Class-1 water specified in GB/T 6682 are used.

5.2.1 Tert-butyl methyl ether

NOTE: The standard stock solution shall be stored at -18°C away from light and has a shelf life of 12 months.

Accurately pipette 1 mL of each of the 4 fluorotelomer alcohol (FTOH) standard stock solutions (5.2.5) into a 10 mL volumetric flask; dilute with tert-butyl methyl ether (5.2.1) and make constant to the scale.

NOTE: The fluorotelomer alcohol (FTOH) mixed standard intermediate solution shall be stored at -18°C away from light and has a shelf life of 1 month.

Accurately transfer 0.1mL of each of the 3 fluorinated acrylate (FTA) standard stock solutions (5.2.5) into a 10mL volumetric flask; dilute with tert-butyl methyl ether (5.2.1) and make constant volume to the scale.

NOTE: The fluorinated acrylate (FTA) mixed standard intermediate solution shall be stored at -18°C away from light, and has a shelf life of 1 month.

NOTE: The internal standard stock solution shall be stored at -18°C away from light, and has the shelf life of 3 months.

NOTE: The internal standard substance standard intermediate solution shall be stored at -18°C away from light and has a shelf life of 1 month.

5.2.4 Internal standard substance

Perfluorodecane-1,10-dicarboxylic acid dimethyl ester (CAS No.: 84750-88-9).

5.2.5 Preparation of standard stock solution

1000 mg/L: Accurately weigh 0.100 g (accurate to 0.0001 g) of 4 fluorinated telomer alcohol (FTOH) standard substances (5.2.2) and 0.100 g (accurate to 0.0001 g) of 3 fluorinated acrylate (FTA) standard substances (5.2.3), respectively; dissolve them in tert-butyl methyl ether (5.2.1) and make constant volume to 100 mL.

5.2.6 Mixed intermediate solutions of the four fluorotelomer alcohols

Preparation of 4 fluorotelomer alcohol (FTOH) mixed intermediate solutions, 100 mg/L:

5.2.7 Mixed intermediate solutions of the three fluorinated acrylates

Preparation of 3 fluorinated acrylate (FTA) mixed intermediate solutions, 10mg/L:

5.2.8 Internal standard substance standard stock solution

1000mg/L: Accurately weigh 0.010g (accurate to 0.0001g) of the internal standard substance (5.2.4); dissolve it with tert-butyl methyl ether (5.2.1) and make constant volume to 10mL.

5.2.9 Internal standard substance standard intermediate solution

15 mg/L: Accurately pipette 0.15 mL of the internal standard substance standard stock solution (5.2.8) into a 10 mL volumetric flask; dilute with tert-butyl methyl ether (5.2.1) and make constant volume to the scale.

5.2.10 Mixed standard working solution of the FTOH and FTA

The 4 fluorinated telomer alcohols (FTOH) and 3 fluorinated acrylates (FTA) mixed standard working solutions: The preparation method is shown in Table 3. The mass concentrations of fluorinated telomer alcohols in the mixed standard working solutions are 0.02 mg/L, 0.05 mg/L, 0.1 mg/L, 0.5 mg/L, and 1 mg/L, respectively; and the mass concentrations of fluorinated acrylates are 0.2 mg/L, 0.5 mg/L, 1 mg/L, 5 mg/L, and 10 mg/L, respectively. peak area as the ordinate, and use the ratio of the target compound and internal standard concentration as the abscissa to make a standard working curve; and perform quantification by internal standard method. The response values of fluorinated telomer alcohol (FTOH) and fluorinated acrylate (FTA) in the specimen solution shall be within the linear range of instrument detection. If the content exceeds the range of the standard working curve, dilute to an appropriate concentration with tert-butyl methyl ether solution containing an internal standard concentration of 0.15 mg/L and analyze. The selected ion flow spectra of each target compound are shown in Figure C.28 of Appendix C.

5.2.24 fluorinated telomer alcohol (FTOH) standard substances

Purity >= 95% (mass fraction), see SN 28 to 31 in Table A.1.

5.2.33 fluorinated acrylate (FTA) standard substances

Purity >= 95% (mass fraction), see SN 32 to 34 in Table A.1.

5.5 Blank test

Except for the addition of no sample, all the operation procedures in 5.4 are followed.

5.6 Test data processing

5.6.1 Calculation of results

The test results are expressed by the test results of each fluorinated telomer alcohol (FTOH) or fluorinated acrylate (FTA).

The content of each fluorinated telomer alcohol (FTOH) or fluorinated acrylate (FTA) in the sample is expressed by mass fraction, wi, and the value is expressed in mg/kg, calculated according to Formula (2):

Where:

Aci - the value of the peak area of the internal standard compound in the standard working solution;

Ai - the value of the peak area of the target compound in the specimen solution;

rhoi - the value of the mass concentration of the target compound in the standard working solution, in mg/L;

V - the value of the total volume of tert-butyl methyl ether used for specimen extraction, in mL; f - dilution factor;

Asi - the value of the peak area of the target compound in the standard working solution;

Ac - the value of the peak area of the internal standard compound in the sample solution; m - the value of the specimen mass, in g.

5.6.2 Expression of results

The calculation result is expressed by the arithmetic mean of the results of two parallel determinations, rounded off to two digits after the decimal point according to the rounding value comparison method in 4.3.3 of GB/T 8170-2008.

5.7 Determination lower limit, recovery rate and precision

5.7.1 Determination lower limit

The determination lower limit of this Document for fluorinated telomer alcohol (FTOH) is 10 mg/kg, and the determination lower limit for fluorinated acrylate (FTA) is 1 mg/kg.

5.7.2 Recovery rate

The recovery rate of spiked samples shall be 70%~120%.

5.7.3 Precision

The absolute difference between two independent test results obtained by the same operator using the same equipment and the same test method in the same laboratory and independently testing the same object within a short period of time shall not exceed 10% of the arithmetic mean of the two determination values.