Combining stir-bar sorptive extraction and large volume injection-gas chromatography-mass spectrometry for the determination of benzotriazole UV stabilizers in wastewater matrices.
Stir-bar sorptive extraction and liquid desorption followed by large volume injection-gas chromatography coupled to mass spectrometry under selected ion monitoring mode acquisition (SBSE-LD/LVI-GC-MS(SIM)) was applied for the determination of six benzotriazole UV stabilizers (Tinuvin P, Allyl-bzt, Tinuvin 320, Tinuvin 326, Tinuvin 327 and Tinuvin 328) in wastewater matrices. Parameters affecting the performance of extraction and desorption steps were thoroughly evaluated using uni- and multivariate optimization strategies, based on the use of experimental factorial designs. Assays performed with stir bars, coated with 24 μL of polydimethylsiloxane, on 25 mL of ultra-pure water samples spiked at the 0.5 ng/mL level, yielded recoveries ranging from 47.9±1.4% (Tinuvin P) to 103.1±3.6% (Tinuvin 326), under optimized experimental conditions. When applied to complex matrices (e.g. wastewater), the methodology showed also excellent linear dynamic ranges (0.02-10.00 ng/mL) for the six benzotriazole UV stabilizers studied with correlation coefficients higher than 0.9970, limits of quantification in between 0.004 and 0.015 ng/mL, suitable repeatability (RSD<12.7%) and reproducibility (RSD<4.5%). The application of the proposed methodology to urban sewage waters from Spain and Portugal wastewater plants revealed the presence of low contents of some benzotriazole UV stabilizers.
Department of Analytical Chemistry, Nutrition and Food Science, Institute for Food Analysis and Research-IIAA, University of Santiago de Compostela, Santiago de Compostela, Spain.
Inma
I
Carpinteiro
Maria
M
Ramil
Isaac
I
Rodríguez
José Manuel F
JM
Nogueira
D005591:Chemical Fractionation; D008401:Gas Chromatography-Mass Spectrometry; D015394:Molecular Structure; D013056:Spectrophotometry, Ultraviolet; D014230:Triazoles / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis*
D014230:Triazoles; D014874:Water Pollutants, Chemical; C012771:benzotriazole