Extraction–Chromatographic Determination of the Total Concentration of Monocyclic Arenes С 6 –С 9 in Wastewater

Abstract

To control the technogenic pollution of water bodies, we proposed to determine the total concentration monocyclic arenes C6–C9 (cAr, mg/L), which are the most toxic and readily water-soluble hydrocarbons. In contrast to the widely used indicator “petroleum products,” the value of сAr directly characterizes the toxicity of the water under study. We developed a procedure for the extraction–chromatographic determination of cAr in wastewater, which does not require the evaporation of the extract or the preparative separation of arenes from other hydrocarbons. The cAr values were calculated from the total areas of arene peaks identified in the chromatogram of a purified hexane extract. To take into account the loss of arenes during sample preparation, the calibration dependence was constructed using multicomponent aqueous solutions with known cAr values (simulating solutions), by passing them through the same operations as the samples of the test water. The lower limit of the determined values of cAr is 0.1 mg/L; the errors in determining cAr do not exceed 15 rel %; the duration of analysis of a single sample is 2 h. The procedure was tested in the analysis of various types of wastewater, verified, and patented.