METHOD OF DETERMINING TIME OF CONTACT BETWEEN DIESEL FUEL AND WATER Russian patent published in 2010 - IPC G01N30/02 G01N33/22 G01N33/18 

FIELD: chemistry.

SUBSTANCE: method involves taking a sample, concentration of impurities, chromatographic analysis with separation of the concentrate on a capillary column and mass-selective detection while raising temperature from 35°C to 280°C, isolation of tridecane and 1-methylnaphthalene as reference compounds on the chromatogram, calculation of their concentration ratio in the sample and calculation of the time of contact between diesel fuel and water using the formula: x=0.42·y^-1.8, where x is the time of contact between diesel fuel and water, h; y=S_tridecane/S_{methylnaphthalene}; S_tridecane and S_{methylnaphthalene} are area of peaks of tridecane and 1-methylnaphthalene on reconstructed chromatograms on selective ions with mass to charge ratio of 85 for tridecane and 145 for 1-methylnaphthalene, which correspond to concentrations of given compounds in the sample.

EFFECT: simple and reliable method with high information content.

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