Development of a dispersive liquid-liquid microextraction method for the determination of plastic additives in seawater.

A method using dispersive liquid-liquid microextraction (DLLME) prior to high performance liquid chromatography-diode array detection (HPLC-DAD) was developed to determine seven additives from the plastics industry (butylated hydroxytoluene, diisodecyl phthalate, irgafos 168, lawsone, quercetin, triclosan and vitamin E) in seawater samples. These compounds can reach seawater due to direct discharge from wastewater treatment plants and leaching from plastics and microplastics. The extraction was performed using 25 mL of seawater, 500 μL of 1-octanol (extraction solvent) and a stirring step instead of dispersive solvent.

A Simple Method for the Determination of Triazines from Seawater in Accordance with the Directive 2013/39/EU.

Since the Directive 2013/39/EU included terbutryn to the list of priority substances of all water bodies, a previous method based on dispersive liquid-liquid micro-extraction (DLLME) for the determination of triazines in seawater has been modified. The main change consisted on the use of tandem mass spectrometry instead of diode array as detection technique. Due to the higher sensitivity of mass detector, sample volume was reduced and extraction solvent volume was optimized.

Application of a developed method for the extraction of triazines in surface waters and storage prior to analysis to seawaters of Galicia (northwest Spain).

A simple method based on solid-phase extraction combined with liquid chromatography for simultaneous determination of nine triazine herbicides (ametryn, atrazine, cyanazine, prometryn, propazine, simazine, simetryn, terbuthylazine, and terbutryn) in surface water samples was developed and validated. Under optimized conditions, 50 mL of water sample was pumped through the Oasis HLB cartridge, and triazines were eluted with 3 mL acetone. Finally the extract was concentrated to dryness, reconstituted with 1 mL methanol : water (1 : 1) and injected into the HPLC-DAD system.

Analytical methodology for the determination of organochlorine pesticides in vegetation.

Due to the extensive use of organochlorine pesticides (OCPs) for agricultural purposes and their high persistence and low biodegradability, they have become an important group of contaminants. Detection and quantification of pesticide residues in food, particularly fruits and vegetables, is of growing concern for producers, consumers, and governments. The most widely used pretreatment for the extraction of pesticides in plants is based on solvent extraction liquid-solid extraction (LSE).