METHOD FOR DETECTION OF ETHYLENEGLYCOL IN WATER SOLUTIONS Russian patent published in 2016 - IPC G01N30/00 

FIELD: chemistry.

SUBSTANCE: method for ethyleneglycol detection in water solutions includes sampling water to be tested in volumetric flask and introduction of internal standard in it. Then calibrated solutions are pre-prepared; 5 ml of internal standard are placed into each of five volumetric weighed flasks with volume 100 ml. Then weight of internal standard is determined, respectively 0; 2; 5; 10 and 20 ml of ethyleneglycol are added into volumetric flasks with internal standard. Volumetric flasks are weighed and distilled water is added to the mark, then are applied on potassium bromide glass and analysed by method of infrared spectrometry, measuring transmission spectrum of solution in area of wave numbers 450-4000 cm^-1 by Fourier-spectrometer with resolution not less than 1cm^-1. Then, concentration of internal standard C_is (g/dm³) and concentration of ethyleneglycol C_e (g/dm³) in calibrating solution are calculated for each solution, calculation of spectrum of optical density in area of selected analytical frequency, normalised per value of concentration of internal standard in calibrating solution, is carried out by software, value of reduced optical density D_red (dm³/mg) is determined by method of baseline by graph at definite frequency (cm^-1), obtained values of reduced optical density D_red (dm³/mg) and concentration of ethyleneglycol C_e (g/cm³) in solution are used to build calibrating graph. Then, 5 ml of internal standard are placed into preliminarily weighed volumetric flask for tested water sample (hereinafter volumetric flask), with volume 100 ml, weight of internal standard is found by difference of weights of volumetric flask with internal standard and preliminarily weighed volumetric flask, volumetric flask is filled to mark with water to be tested, concentration of internal standard C_is (g/dm³), introduced into water sample to be tested, is calculated. Obtained solution is mixed for 5 min and applied in thin layer on potassium bromide glass; analysis by method of infrared spectrometry is carried out, with measurement of transmission spectrum of water sample with introduced internal standard in area 450-4000 cm^-1. Then, calculation of spectrum of optical density in area of selected analytical frequency, normalised per value of concentration of internal standard, is carried out by software, value of reduced optical density D_red (dm³/mg) for tested water sample is determined by method of baseline at selected analytical frequency, concentration of ethyleneglycol C_is (g/dm³) in tested water sample is determined by calibrating graph by measured value at analytic frequency of reduced optical density D_red (dm³/mg) or by predetermined calibrating dependence.

EFFECT: reduction of time for realisation and simplification of process of quantitative determination of ethyleneglycol in water samples.

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