Determination of UV filters in both soluble and particulate fractions of seawaters by dispersive liquid-liquid microextraction followed by gas chromatography-mass spectrometry.
An analytical method to determine the total content (i.e., not only in the soluble fraction but also in the particulate one) of eight commonly used UV filters in seawater samples is presented for the first time. Dispersive liquid-liquid microextraction (DLLME) is used as microextraction technique to pre-concentrate the target analytes before their determination by gas chromatography-mass spectrometry (GC-MS). In order to release the UV filters from the suspended particles an ultrasound treatment is performed before DLLME. The ultrasound treatment time was studied in order to achieve a quantitative lixiviation of the target analytes. The type and volume of both disperser and extraction solvent, the sample volume, the pH and the ionic strength involved in the DLLME have been optimized to provide the best enrichment factors. Under the optimized conditions, the method was successfully validated showing good linearity, enrichment factors between 112 and 263 depending on the analyte, limits of detection and quantification in the low ng L(-1) range (10-30 ng L(-1) and 33-99 ng L(-1), respectively) and good intra- and inter-day repeatability (RSD <15%). No significant matrix effects were found. Finally, the method was satisfactorily applied to the analysis of three seawater samples from different origin. Results showed significant amounts of UV filters in the particulate fraction that would have been ignored if only the soluble fraction had been considered. This fact shows that the UV filters are also accumulated in the suspended particles contained in water, what should be taken into account from an environmental standpoint.
Departamento de Química Analítica, Facultad de Química, Universitat de València, 46100 Burjassot, Valencia, Spain.
J L
JL
Benedé
Departamento de Química Analítica, Facultad de Química, Universitat de València, 46100 Burjassot, Valencia, Spain. Electronic address: alberto.chisvert@uv.es.
A
A
Chisvert
Departamento de Química Analítica, Facultad de Química, Universitat de València, 46100 Burjassot, Valencia, Spain.
A
A
Salvador
Department of Global Change Research, Mediterranean Institute for Advanced Studies, (UIB-CSIC) , 07190 Esporles, Balearic Islands, Spain.
D
D
Sánchez-Quiles
Department of Global Change Research, Mediterranean Institute for Advanced Studies, (UIB-CSIC) , 07190 Esporles, Balearic Islands, Spain; Department of Ecology and Coastal Management. Instituto de Ciencias Marinas de Andalucía (CSIC). Campus Rio San Pedro. 11510 Puerto Real (Cadiz) Spain.
A
A
Tovar-Sánchez
D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D059627:Liquid Phase Microextraction / Q000379:methods*; D009994:Osmolar Concentration; D012623:Seawater / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry; D014466:Ultraviolet Rays
D012997:Solvents
Dispersive liquid–liquid microextraction; Gas chromatography–mass spectrometry; Seawater analysis; Trace analysis; UV filters; Ultrasound treatment