Home – Home – Jornals – Chemistry for Sustainable Development 2017 number 4

The contents of di-n-butyl phthalate (DBP) and di (2-ethylhexyl) phthalate (DEHP) were assessed in the Lake Baikal pelagic zone. The spatial heterogeneity of the distribution of phthalates in the upper and deep water levels for all basins of Lake Baikal was determined from 0.06 to 3.1 µg/dm³ of DBP and from 0.03 to 1.4 µg/dm³ of DEHP, seasonal variability of the total concentrations of phthalates in the pelagic zone of the lake being up to 10 times. Background stations of the reference section in three lake basins were proposed as reference areas for monitoring, and the average concentrations of phthalates in the upper aqueous layer (5–200 m) were proposed to assess the present content of phthalates in the water of the lake. The contents of DBP and DEHP in Lake Baikal Water over the period 2015–2016 were 0.35–0.89 and 0.06–0.32 µg/dm³, respectively, and do not exceed the MPC for water bodies specified in Russia. A simultaneous change in DBP concentration in the upper water layer of the pelagic zone of the southern lake basin and in its coastal area as pollution indicator was noted. Phthalates were determined by liquid-liquid extraction of analytes into n-hexane, direct analysis of extracts using chromatography-mass spectrometry in selective detection mode (m/z 149 and 153) and measurements by the internal standard method using di-n-octylphthalate-3,4,5,6-d₄ as a surrogate standard. Secondary pollution of water and extracts with laboratory phthalates was regarded as the systematic error that was assessed by the value of reagent blanks and subtracted from analysis results. The total error was assessed using the values of 25 and 20 % for DBP and DEHP, respectively.