SN/T 5260-2020Determination of Tetrabromobisphenol A and Tris(1,3-Dichloropropyl) Phosphate in Coatings Liquid Chromatography-Mass Spectrometry/Mass Spectrometry (English PDF)

6.1 Extraction

6.1.1 Water-based paint

Weigh about 0.25 g of the mixed sample (accurate to 0.0001 g), place it in a 25 mL colorimetric tube with a stopper, and use ethyl acetate (4.1) Dilute to the mark. After mixing on the vortex mixer (5.3), the ultrasonic cleaner (5.4) extracts for 15 minutes and transfers to a 25 mL stopper.

Centrifuge the tube at a speed of 4 000 r/min for 8 min. Accurately pipette 1 mL of the supernatant, blow dry with nitrogen, and accurately add 1 mL of acetonitrile (4.2) Dissolve. Filter with a 0.22 µm organic phase filter membrane (4.7), and the filtrate is used for liquid chromatography-mass spectrometry/mass spectrometry.

6.1.2 Solvent-based coatings

Weigh about 0.25 g of the mixed sample (accurate to 0.0001 g), place it in a 25 mL colorimetric tube with a stopper, and dilute with acetonitrile (4.2) to the scale. After mixing on the vortex mixer (5.3), the ultrasonic cleaner (5.4) extracts for 15 minutes and transfers to a 25 mL stoppered centrifuge tube.

Centrifuge at a speed of 4 000 r/min for 8 min, take the supernatant and filter it with a 0.22 µm organic phase filter (4.7), and use the filtrate for liquid chromatography-quality Spectro/mass spectrometer determination.

6.2 Determination

6.2.1 Chromatographic reference conditions

Since the test results depend on the instrument used, the general parameters of chromatography/mass spectrometry cannot be given. The following parameters have been proven it is appropriate to test.

a) Chromatographic column. C18 column, 50 mm×2.1 mm (inner diameter), 1.8 µm, or equivalent;

b) Column temperature. 35 °C;

c) Injection volume. 1 µL;

d) Mobile phase. A-water, B-acetonitrile;

e) See Table 1 for gradient elution conditions;

f) Flow rate. 0.3 mL/min.

6.2.2 Reference conditions for mass spectrometry

Since the test results depend on the instrument used, the general parameters of mass spectrometry cannot be given. The following parameters have been proven to be tested Try is appropriate. The parameters of the electrospray ion source (ESI) are shown in Table 2, and the monitoring ion pair and collision energy are shown in Table 3.

6.2.3 Qualitative determination

Determine the sample and standard working solution according to the above conditions. If the retention time of the mass chromatographic peak of the sample is consistent with that of the standard, it is allowed the deviation is less than ±2.5%; the relative abundance of the qualitative ion pair is consistent with the relative abundance of the standard working solution with the same concentration, and the relative abundance allows If the allowable deviation does not exceed the range specified in Table 4, it can be judged that there is a corresponding measured object in the sample.

Table 4 The maximum allowable deviation of relative ion abundance during qualitative confirmation

Relative ion abundance/% > 50 > 20~50 > 10~20 <= 10 Maximum allowable deviation/% ±20 ±25 ±30 ±50

6.2.4 Quantitative determination

Draw a standard working curve with the peak area of the target compound as the ordinate and the concentration as the abscissa, and quantify by external standard method. Standard working solution the response value of the analyte in the sample solution should be within the linear response range of the instrument. If the content exceeds the range of the standard curve, use acetonitrile (4.2) Analyze after diluting to appropriate concentration. Under the above chromatographic conditions, refer to Appendix A for the multiple reaction monitoring (MRM) chromatogram of the standard solution

Figure A.1.

6.2.5 Blank test

Except that no sample is added, all follow the above steps.

6.3 Result calculation

Calculate the content of the substance to be tested in the sample according to formula (1).

6.4 Precision

6.4.1 Repeatability

The same operator uses the same instrument to perform normal and correct experimental methods for the same substance under constant experimental conditions.

The difference between the two consecutive measurement results obtained is not more than 10% of the arithmetic mean of the two measurement values.

6.4.2 Reproducibility

In different laboratories, the same operator uses the same equipment and uses the same test method to test the same object in parallel twice.

The absolute difference of the determined result is not more than 15% of the arithmetic mean of the two measured values.

Appendix A

(Informative appendix)