title: Determination of trace levels of aquaculture chemotherapeutants in seawater samples by SPME-GC-MS/MS.
abstract: A sensitive and efficient solid-phase microextraction (SPME) method for the determination of organophosphorous (OPPs) and pyrethroid pesticides (Pyrs) in aquaculture-seawater samples by using GC with MS/MS (GC-MS/MS) was developed. Dichlorvos and chlorpyrifos (OPPs); permethrin, alpha-cypermethrin and deltamethrin (Pyrs) were selected according to their use as chemotherapeutants in the aquaculture industry. Different parameters affecting extraction efficiency such as fibre coating, agitation, pH and extraction time profiles were investigated. An experimental central composite design (alpha = 1) and desirability functions were used for the simultaneous optimization of extraction temperature and sample volume. Finally, a method based on direct SPME in 40 min at 75 degrees C using 100-microm-thick poly(dimethyl)siloxane (PDMS) fibre and 20 mL of sample volume is proposed. The method was validated, exhibiting good linearity, precision and accuracy parameters with picogram per millilitre LODs. The proposed methodology was applied to determine the ultratrace levels of OPPs and Pyrs in aquaculture-seawater samples by the standard addition approach, which proved to be reliable and sensitive, in addition to requiring only small amounts of sample.
authors.affiliation: Departamento de Química Analítica, Nutrición y Bromatología, Instituto de Investigación y Análisis Alimentario, Facultad de Química, Universidad de Santiago de Compostela, Santiago de Compostela, Spain.
authors.forename: Diego
authors.initials: D
authors.lastname: García-Rodríguez
authors.forename: Antonia M
authors.initials: AM
authors.lastname: Carro
authors.forename: Rosa A
authors.initials: RA
authors.lastname: Lorenzo
authors.forename: Fátima
authors.initials: F
authors.lastname: Fernández
authors.forename: Rafael
authors.initials: R
authors.lastname: Cela
mesh_terms: D000981:Antiprotozoal Agents / Q000032:analysis*; D017756:Aquaculture; D004390:Chlorpyrifos / Q000032:analysis; D004006:Dichlorvos / Q000032:analysis; D004129:Dimethylpolysiloxanes / Q000737:chemistry; D008401:Gas Chromatography-Mass Spectrometry / Q000295:instrumentation / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D015394:Molecular Structure; D009570:Nitriles / Q000032:analysis; D026023:Permethrin / Q000032:analysis; D011722:Pyrethrins / Q000032:analysis; D015203:Reproducibility of Results; D012623:Seawater / Q000737:chemistry*; D012680:Sensitivity and Specificity; D052617:Solid Phase Microextraction / Q000295:instrumentation / Q000379:methods*; D013237:Stereoisomerism; D013499:Surface Properties; D013696:Temperature; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000032:analysis
chemical_list: D000981:Antiprotozoal Agents; D004129:Dimethylpolysiloxanes; D009570:Nitriles; D011722:Pyrethrins; D014874:Water Pollutants, Chemical; C017160:cypermethrin; C017180:decamethrin; D026023:Permethrin; D004006:Dichlorvos; D004390:Chlorpyrifos