Evaluation of polyethersulfone performance for the microextraction of polar chlorinated herbicides from environmental water samples.
In this work, the suitability of bulk polyethersulfone (PES) for sorptive microextraction of eight polar, chlorinated phenoxy acids and dicamba from environmental water samples is assessed and the analytical features of the optimized method are compared to those reported for other microextraction techniques. Under optimized conditions, extractions were performed with samples (18 mL) adjusted at pH 2 and containing a 30% (w/v) of sodium chloride, using a tubular PES sorbent (1 cm length × 0.7 mm o.d., sorbent volume 8 µL). Equilibrium conditions were achieved after 3h of direct sampling, with absolute extraction efficiencies ranging from 39 to 66%, depending on the compound. Analytes were recovered soaking the polymer with 0.1 mL of ethyl acetate, derivatized and determined by gas chromatography-mass spectrometry (GC-MS). Achieved quantification limits (LOQs) varied between 0.005 and 0.073 ng mL(-1). After normalization with the internal surrogate (IS), the efficiency of the extraction was only moderately affected by the particular characteristics of different water samples (surface and sewage water); thus, pseudo-external calibration, using spiked ultrapure water solutions, can be used as quantification technique. The reduced cost of the PES polymer allowed considering it as a disposable sorbent, avoiding variations in the performance of the extraction due to cross-contamination problems and/or surface modification with usage.
Department of Analytical Chemistry, University of the Basque Country, P.K. 644, 48080 Bilbao, Spain.
Ailette
A
Prieto
Department of Analytical Chemistry, Nutrition and Food Science, IIAA-Institute for Food Analysis and Research, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain.
Rosario
R
Rodil
Department of Analytical Chemistry, Nutrition and Food Science, IIAA-Institute for Food Analysis and Research, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain.
José Benito
JB
Quintana
Department of Analytical Chemistry, Nutrition and Food Science, IIAA-Institute for Food Analysis and Research, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain.
Rafael
R
Cela
Department of Analytical Chemistry, Helmholtz Centre for Environmental Research-UFZ, Permoserstraße 15, D-04318 Leipzig, Germany.
Monika
M
Möder
Department of Analytical Chemistry, Nutrition and Food Science, IIAA-Institute for Food Analysis and Research, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain. Electronic address: isaac.rodriguez@usc.es.
Isaac
I
Rodríguez
D004784:Environmental Monitoring / Q000379:methods; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D054879:Halogenation; D006540:Herbicides / Q000032:analysis* / Q000737:chemistry; D011108:Polymers / Q000032:analysis* / Q000737:chemistry*; D052617:Solid Phase Microextraction / Q000379:methods; D013450:Sulfones / Q000032:analysis* / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis*
D006540:Herbicides; D011108:Polymers; D013450:Sulfones; D014874:Water Pollutants, Chemical; C022840:polyether sulfone
Gas chromatography–mass spectrometry; Polar acidic herbicides; Polyethersulfone; Sorptive extraction; Water samples