METHOD FOR QUANTITATIVE DETERMINATION OF THE CONTENT OF TRICHLOROETHYLENE AND TETRACHLOROETHYLENE IN ATMOSPHERIC AIR BY GAS CHROMATOGRAPHY WITH ELECTRON CAPTURE DETECTION Russian patent published in 2021 - IPC G01N30/02 

FIELD: analytical chemistry.

SUBSTANCE: invention relates to analytical chemistry. A method for quantifying the content of trichloroethylene and tetrachloroethylene in atmospheric air by gas chromatography with electron capture detection includes air sampling by pumping through a sorption tube filled with a sorbent, subsequent thermal desorption, removal of a chromatogram and determination of the content of trichloroethylene and tetrachloroethylene according to a calibration schedule, while air sampling is performed by pumping air through a pre-cooled to 0°C sorption tube, filled with Tenax TA sorbent and at a rate of 0.1 l/min for 10 minutes; the air temperature and atmospheric pressure are recorded at the time of sampling, then the sorption tube with an air sample is subjected to thermal desorption in a thermal desorber, for this one end of the tube is connected to the capillary column of a gas chromatograph, the tube is heated to 250°C, after that a carrier gas (nitrogen) flow is passed through the second end of the tube for 10 minutes, at a speed of 20 cm³/min to carry the selected air sample into the trap, and the direction of the gas flow in the tube is opposite to the direction of the air flow into this tube during sampling, the sample is heated in the trap at 250°C for 2 minutes and the sample is analyzed, for this purpose, the sample is first held for trichloroethylene for 13.56 minutes, for tetrachloroethylene for 16.8 minutes, a chromatogram is taken, determining the peak area, and the concentration of trichloroethylene and tetrachloroethylene in the air is determined using a calibration graph, characterizing the dependence of the peak area from the content of the studied component in the chromatogram given taking into account the volume of air sampled for analysis to normal conditions, the analysis of concentrated air samples is carried out by capillary column BPX ID-VOL, 60 m*0.32 mm*1.8 mcm at temperature modes: column 50°C-100°C-230°C; evaporator 250°C; detector 250°C; flow rate of carrier gas (nitrogen) - 20 ml/min.

EFFECT: creation of a highly sensitive and selective method for monitoring trichloroethylene and tetrachloroethylene in atmospheric air with low detection limits.

1 cl, 1 dwg, 5 tbl