Effects of ultrasonic irradiation and direct heating on extraction of priority pesticides from marine sediments

Priority pesticides (alachlor, aldrin, γ-chlordane, chlorfenvinphos, chlorpyrifos, dieldrin, 4,4′-DDT, 4,4′-DDD, 4,4′-DDE, α-endosulfan, β-endosulfan, endosulfan sulphate, endrin, α-HCH, β-HCH, γ-HCH, δ-HCH, HCB, HCBD, heptachlor, heptachlor epoxide, isodrin, methoxychlor, mirex, quintozene, terbuthylazine and trifluralin) are a group of toxic substances that are known by their persistency in the aquatic environment. Their screening in marine sediments may provide information on the sources and distribution in the water mass of fresh-transitional and coastal waters. This work proposes a rapid and reliable method to extract multi-residues of priority pesticides by ultrasounds irradiation from marine sediments. Multiple variables have been optimised: ultrasound frequency, sonication intensity, signal operation mode, time of extraction and water bath temperature. After sample clean-up and pre-concentration of the pesticides by stir bar sorptive extraction, the compounds were analysed by gas chromatography-ma...