The detection method of polydimethylsiloxane comprises the following specific steps:
(1) Weigh a certain amount of sample, add organic solvent, extract dimethyl silicone oil by ultrasonic vibration, concentrate the extract, and then put it on a silica gel column, first rinse with eluent to remove grease impurities, discard the eluent, and then use The dimethyl silicone oil is eluted by deliquoring, the eluate is collected, and after concentration, the sample solution is obtained;
(2) Take the polydimethylsiloxane standard solution with a concentration of 10-500 mg/L and the sample solution prepared in step (1), and perform fragmentation chromatography/mass spectrometry analysis; record their total ion currents by mass spectrometry full scan Chromatogram (TIC), the main characteristic component of polydimethylsiloxane cleavage product is hexamethylcyclotrisiloxane. Take m/z 207, 191, 177, 133 as the characteristic ions of mass spectrum for the determination of hexamethylcyclotrisiloxane.
(3) Using hexamethylcyclotrisiloxane, the component with the highest content in the pyrolysis product, as the indicator component for the qualitative detection of polydimethylsiloxane, extracting ion chromatography was performed on the total ion chromatograms of the standard solution and the sample solution, respectively. Figure (EIC), check whether there is a peak at the position of hexamethylcyclotrisiloxane (whether the retention time is the same) in the EIC diagram of the corresponding standard product in the EIC diagram of the sample, which proves that the sample contains polydimethylsiloxane.
(4) The hexamethylcyclotrisiloxane in the cleavage product was used as the indicator component for the quantitative detection of polydimethylsiloxane, and m/z 207 was used as the quantitative ion of hexamethylcyclotrisiloxane, respectively. Extracted ion diagram (EIC) was made for the TIC diagram of the standard and the sample, and the content of polydimethylsiloxane was calculated by the external standard method according to the peak area ratio of the standard and the sample m/z 207.