METHOD OF DETERMINING CONTENT OF BENZ(A)PYRENE IN TECHNICAL CARBON Russian patent published in 2013 - IPC G01N30/00 

FIELD: chemistry.

SUBSTANCE: invention relates to methods of analysing materials using gas chromatography coupled with quadrupole mass spectrometry (hereinafter GC/MS) and can be used in industrial and scientific research laboratories when analysing the quality of technical carbon (industrial soot). The method of determining content of benz(a)pyrene in technical carbon involves sampling technical carbon (hereinafter sample), extracting benz(a)pyrene with a solvent which is associated with a class of aromatic hydrocarbons, separating the extract during production thereof, calculating the mass concentration of benz(a)pyrene in the extract and determining content thereof in the sample. After sampling, the sample is put into a pre-weighed vessel. The mass of the vessel with the sample is then measured and the mass of the sample m_c (r) is determined by determining the difference between the mass of the empty vessel and the vessel with the sample. Further, toluene is added to the vessel with the sample as an extracted and the vessel is then put into an extractor where benz(a)pyrene is extracted from the sample for 30-50 minutes while stirring. The mixture of the extract and the sample is then separated. The extract is separated, while putting it into the pre-weighed vessel which is closed by a ground stopper. Further, by adding toluene into the vessel with the sample and the remaining extract, at least 5 extractions of benz(a)pyrene are carried out with subsequent separation of the extract and putting it into the vessel with the ground stopper. The mass of the obtained extract is determined by measuring mass of the empty vessel with the ground stopper and the vessel with the ground stopper with the extract and determining the difference. The sample extract is fed into the evaporator of the GC/MS and the output signal is detected, while determining the presence of benz(a)pyrene from the appearance of a corresponding peak on the mass-chromatogram; further, the area o the benz(a)pyrene peak is measured and mass concentration of benz(a)pyrene C_b(a)p (mcg/cm³) in the extract is determined from the obtained area of the peak using a calibration curve. The volume of the extract V₃ (cm³), is then determined and content of benz(a)pyrene in the sample is determined by calculating its weight ratio (X, %) in the sample using the formula X=(C_b(a)p·V₃)/m_c.

EFFECT: wider range of equipment for a similar purpose.

2 tbl, 3 dwg