Development and adaptation of methods for PAHs extraction from bottom sediments using subcritical water extraction, saponification, and ultrasound extraction

Polycyclic aromatic hydrocarbons (PAHs) are persistent organic pollutants that pose significant environmental and health risks due to their widespread distribution and carcinogenic properties. Developing efficient and environmentally friendly extraction methods for PAHs from complex matrices like bottom sediments is essential for advancing pollution monitoring and mitigation efforts. The influence of temperature and time parameters of water in a subcritical state on the extraction of widespread, contrasting in physicochemical properties polycyclic aromatic hydrocarbons (PAHs) from bottom sediment samples of the Lena River with varying initial pollutant content was studied. It was shown that the optimal extraction parameters for naphthalene are 240°C for 20 minutes, for phenanthrene and fluoranthene – 240°C for 30 minutes, for benzo(a)pyrene – 250°C for 30 minutes, and for benzo(g,h,i)perylene – 260°C for 40 minutes. Under these conditions, the proportion of extracted PAHs varies from 76% to 85%. A comparison was conducted of widely used PAH extraction methods based on the use of toxic solvents from standard techniques. It was established that the efficiency of extraction methods can be ranked as follows: ultrasound extraction > subcritical extraction > saponification method. In this case, the value of the PAH extraction coefficient during subcritical extraction was 1.23-1.29, during saponification - 1.35 and 1.34, and during the ultrasonic extraction method - 1.10 and 1.08.