METHOD OF DETERMINING TIME OF PETROL-TO-WATER CONTACT Russian patent published in 2008 - IPC G01N30/02 G01N33/22 G01N33/18 

FIELD: ecology; analytical chemistry.

SUBSTANCE: method includes sampling, concentration of volatile impurities, chromatographic analysis including the concentrate separation on a capillary column with a polar stationary liquid phase and flame-ionisation detection with holding at 60° C, temperature rise at a rate of 10° C/min to 120° C and holding at this temperature, isolation of toluene and 1,2,4-trimethylbenzene as reference compounds, determining proportion of their concentrations in the sample, and calculation of the time of petrol-to-water contact by the formula: x = (2.27 - y)/ 0.023 where x is the time of petrol-to-water contact, hours; y is S_toluene/S_{1,2,4 - TMB}, S_toluene and S_{1,2,4 - TMB} - concentrations of toluene and 1,2,4-trimethylbenzene in the sample corresponding to areas of the peaks in the chromatogram.

EFFECT: higher reliability of determination.

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