Extraction of Fipronil and Thiobencarb from Anaerobic Water Samples Using Solid-Phase Extraction
| Autor: | Philip Eberbach, Stuart Helliwell, Gregory Doran |
|---|---|
| Rok vydání: | 2005 |
| Předmět: |
Insecticides
Chromatography Gas Time Factors Iron Hydrochloric acid Ascorbic Acid Analytical Chemistry chemistry.chemical_compound Colloid Thiocarbamates Environmental Chemistry Colloids Solid phase extraction Pesticides Fipronil Pharmacology Chromatography Dose-Response Relationship Drug Herbicides Extraction (chemistry) Pesticide Residues Water Ascorbic acid Oxygen chemistry Pyrazoles Degradation (geology) Hydrochloric Acid Agronomy and Crop Science Anaerobic exercise Water Pollutants Chemical Food Science |
| Zdroj: | Scopus-Elsevier Charles Sturt University |
| ISSN: | 1944-7922 1060-3271 |
| Popis: | Anaerobic water samples containing levels of soluble Fe(II) may form insoluble Fe(III) particulates that could hinder subsequent extraction and analysis. Solid-phase extraction (SPE) cartridges could become blocked by this material, reducing the volume that can be processed. The ability of ascorbic acid to reduce these Fe(III) colloids and/or to prevent further oxidation of Fe(II) by dissolved oxygen during sampling was investigated and compared to sample stabilization with hydrochloric acid. Ascorbic acid (5%, w/v) proved the most effective treatment because it prevented 95% of the dissolved iron in the sample from precipitating during processing, compared to 40% in untreated samples. The effect of ascorbic acid addition on degradation of 2 rice pesticides, fipronil and thiobencarb, was investigated and compared to degradation rates in water. Pesticide reduction by ascorbic acid over a 3 h period was insignificant compared to the natural degradation occurring in deionized water. While this method was shown to increase sample processing time, it also allowed the processing of large-volume anaerobic water samples (150 mL) that were previously not extractable due to rapid obstruction of the SPE cartridge. |
| Databáze: | OpenAIRE |
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