Hydroxypropyl-β-cyclodextrin-based extraction for diuron bioaccessibility in an artificially contaminated soil

Different extraction techniques are presented here to determine whether their extraction abilities correlate with the bioaccessible diuron fraction in an aged contaminated soil. Diuron bioaccessibility was tested establishing correlations between the amount of diuron biodegraded after different aging periods, using a specific diuron biodegrader microorganism consortium, and the amount of diuron extracted by 50mM hydroxypropyl--cyclodextrin (HPBCD), 10mM CaCl2, hexane, or butanol. HPBCD extraction procedure correlated better than the other extraction techniques tested with diuron measured microbial biodegradation for all aging times (1, 30, 60, 90, and 120 days). The results obtained with this soil indicate that the aqueous HPBCD extraction technique has potential to become a valuable tool for estimating the bioaccessible fraction of soil-associated diuron at different aging times, and it could be applicable in the assessment of risk and contaminated land bioremediation potential.