SN/T 5267-2020Determination of carragaldehyde in detergents gas chromatography-mass spectrometry (English PDF)

5.1 Extraction

5.1.1 Soap and powder solid samples

Crush the sample to a particle size of less than 2 mm, weigh 0.5 g (accurate to 0.1 mg), and put it into a 25 mL conical flask (4.6) with a stopper.

Ultrasonic extraction with 10 mL methanol (3.1) for 30 min. After the extraction is completed, it is filtered through quantitative filter paper (3.7) to a 50 mL round bottom flask (4.9), Use 2 mL methanol (3.1) to rinse the stoppered Erlenmeyer flask (4.6) and the sample, and add the extract. The extract is concentrated with a rotary evaporator (4.4) to close to 1 mL, to be purified.

5.1.2 Liquid samples

Accurately weigh 0.5 g (accurate to 0.1 mg) of the sample, put it into a 10 mL test tube (4.7) with a stopper, and use 1 mL of methanol (3.1) to supersede it.

Acoustic extraction for 30 minutes, to be purified.

5.2 Purification

Transfer the purified solution to the activated silica gel cartridge (3.5), eluting with 6 mL methanol (3.1), collect the eluate, and use methanol (3.1) Dilute the volume to 10 mL, and then filter through the organic phase microporous membrane (3.6) for testing.

6.1 Reference conditions for gas chromatography-mass spectrometry

Since the test results depend on the instrument used, it is impossible to give general parameters for gas chromatography-mass spectrometry. Set parameters it should be ensured that the measured component and other components can be effectively separated during chromatographic determination. The following parameters have been proved to be feasible.

a) Chromatographic column. DB-5MS, 30 m×0.25 mm (inner diameter)×0.25 µm (film thickness), or equivalent;

b) Column temperature. 120 °C, keep for 1 min; 10 °C/min increase to 260 °C, keep 10 min; 20 °C/min increase to 290 °C, Keep for 2 min;

c) Temperature of the injection port. 280 °C;

d) Carrier gas. helium, purity >= 99.999%, 1.0 mL/min;

e) Chromatography-mass spectrometry interface temperature. 300 °C;

f) Ion source temperature. 230 °C;

g) Quadrupole temperature. 150 °C;

h) Ionization method. EI;

i) Ionization energy. 70 eV;

j) Scanning range. m/z 50~450;

k) Measurement method. SCAN mode;

l) Injection volume. 1.0 µL, without splitting;

m) Solvent delay. 4 min.

6.2 Drawing a standard working curve

According to the reference conditions listed in 6.1, the standard working solution (3.4) was determined by gas chromatography-mass spectrometry. Take the measured substance concentration as horizontal Coordinates, with the peak area corresponding to the quantitative ion as the ordinate, draw a standard working curve to obtain a linear equation. Typical carragaldehyde standard refer to Figure A.1 in Appendix A for the total ion current diagram of solution gas chromatography-mass spectrometry.

6.3 Qualitative and quantitative analysis by gas chromatography-mass spectrometry

Analyze the test solution according to the above reference conditions (6.1). According to the retention time of the chromatographic peak, refer to the card in Table B.1 in Appendix B Qualitative analysis was performed on the qualitative ions of lamanthaldehyde. Perform quantitative analysis according to the standard working curve (6.2).

6.4 Blank test

Carry out a blank test along with the sample, and perform pre-processing and testing in accordance with the sample processing steps.