Analysis of phthalic acid esters in agricultural soils

The aim of the study was monitoring of phthalic acid esters in agricultural soils of the Czech Republic over the period of 6 years, namely dibutyl phthalate (DBP) and di-2-ethylhexyl phthalate (DEHP). Monitoring took place in twelve regions of the Czech Republic. Soil samples were taken evenly from the top and bottom soil horizons using a zig-zag pattern. Soil samples were taken from arable land, permanent grassland, and hop field. Lyophilisation of the samples was done by ultrasound-assisted extraction using a mixture acetone-hexane (1:1). Phthalic acid esters were analysed using high-performance liquid chromatography with UV detection. Subsequently, the results were statistically compared by analysing the principal components (PCA) to determine the effect of individual factors on the content of phthalic acid esters in agricultural soil. Factors such as precipitation, distance from a pollution source, amount of pesticides, and amount of artificial and organic fertilizers were taken into account. If we compare the concentrations established in this study with the limits set out in the Methodological Instruction of the Ministry of the Environment of the Czech Republic based on RSLs (Regional Screening Levels) issued by the USEPA (United States Environmental Protection Agency), none of these values were exceeded.