title: Application of the experimental design of experiments (DoE) for the determination of organotin compounds in water samples using HS-SPME and GC-MS/MS.
abstract: When attempting to discover the important factors and then optimise a response by tuning these factors, experimental design (design of experiments, DoE) gives a powerful suite of statistical methodology. DoE identify significant factors and then optimise a response with respect to them in method development. In this work, a headspace-solid-phase micro-extraction (HS-SPME) combined with gas chromatography tandem mass spectrometry (GC-MS/MS) methodology for the simultaneous determination of six important organotin compounds namely monobutyltin (MBT), dibutyltin (DBT), tributyltin (TBT), monophenyltin (MPhT), diphenyltin (DPhT), triphenyltin (TPhT) has been optimized using a statistical design of experiments (DOE). The analytical method is based on the ethylation with NaBEt4 and simultaneous headspace-solid-phase micro-extraction of the derivative compounds followed by GC-MS/MS analysis. The main experimental parameters influencing the extraction efficiency selected for optimization were pre-incubation time, incubation temperature, agitator speed, extraction time, desorption temperature, buffer (pH, concentration and volume), headspace volume, sample salinity, preparation of standards, ultrasonic time and desorption time in the injector. The main factors (excitation voltage, excitation time, ion source temperature, isolation time and electron energy) affecting the GC-IT-MS/MS response were also optimized using the same statistical design of experiments. The proposed method presented good linearity (coefficient of determination R(2)>0.99) and repeatibilty (1-25%) for all the compounds under study. The accuracy of the method measured as the average percentage recovery of the compounds in spiked surface and marine waters was higher than 70% for all compounds studied. Finally, the optimized methodology was applied to real aqueous samples enabled the simultaneous determination of all compounds under study in surface and marine water samples obtained from Valencia region (Spain).
authors.affiliation: Center for Public Health Research (FISABIO), 21 Avenida Catalunya, 46020 Valencia, Spain. Electronic address: coscolla_cla@gva.es.
authors.forename: Clara
authors.initials: C
authors.lastname: Coscollà
authors.affiliation: Center for Public Health Research (FISABIO), 21 Avenida Catalunya, 46020 Valencia, Spain.
authors.forename: Santiago
authors.initials: S
authors.lastname: Navarro-Olivares
authors.affiliation: Center for Public Health Research (FISABIO), 21 Avenida Catalunya, 46020 Valencia, Spain.
authors.forename: Pedro
authors.initials: P
authors.lastname: Martí
authors.affiliation: Center for Public Health Research (FISABIO), 21 Avenida Catalunya, 46020 Valencia, Spain.
authors.forename: Vicent
authors.initials: V
authors.lastname: Yusà
mesh_terms: D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D009947:Organotin Compounds / Q000032:analysis*; D052617:Solid Phase Microextraction / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D009947:Organotin Compounds; D014874:Water Pollutants, Chemical
keywords: Design of experiments; GC–MS/MS; Organotin compounds; Solid-phase microextraction; Water analysis