Yankuang ceshi (May 2021)
Determination of Carbofuran and 3-Hydroxycarbofuran in Groundwater by Small Volume Liquid-Liquid Extraction Combined with GC-MS
Abstract
BACKGROUND Carbofuran and 3-hydroxycarbofuran are typical pesticides with the relationship of parent and metabolite. Due to high water solubility and toxicity, carbofuran and 3-hydroxycarbofuran can be transported through surface water or groundwater for long distances, causing harm to human health and environmental safety. In the past, carbofuran and 3-hydroxycarbofuran in samples were usually extracted by liquid or solid phase extraction. However, these methods are cumbersome to operate and time-consuming, which is not conducive to the detection of multiple sets of samples in indoor simulation experiments. OBJECTIVES In order to realize the rapid quantification of carbofuran and 3-hydroxycarbofuran in groundwater. METHODS A small volume liquid-liquid extraction pretreatment method was established for extraction, combined with gas chromatography-mass spectrometry to detect factors affecting the extraction efficiency of carbofuran and 3-hydroxycarbofuran. To improve the extraction efficiency of carbofuran and 3-hydroxycarbofuran, [JP] factors such as the type of extraction solvent, pH and dosage of NaCl were optimized. RESULTS Results showed that the extraction efficiency of carbofuran and 3-hydroxycarbofuran was highest when 1mL methylene chloride was selected as the extraction agent under pH=5, and 40g/L NaCl was added in the water samples. The extraction recoveries for carbofuran and 3-hydroxycarbofuran were 75.1%-98.6% and 55.0%-66.3%, respectively. The performance evaluation results showed that the instrument precision and method precision meet test requirements (n=5, relative standard deviation < 10%). The detection limits of carbofuran and 3-hydroxycarbofuran in water were 15.3μg/L and 10.2μg/L, respectively. CONCLUSIONS This method is simple and fast with less solvent. Compared with the traditional liquid-liquid extraction method, this method takes about 1/8 time of the former, and consumes about two orders of magnitude less solvent than the former, which can meet the needs of indoor simulation experiments.
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