Improved solvent collection system for a dispersive liquid–liquid microextraction of organochlorine pesticides from water using low-density organic solvent
✍ Scribed by Chu-Chi Chang; Shuo-Yang Wei; Shang-Da Huang
- Publisher
- John Wiley and Sons
- Year
- 2011
- Tongue
- English
- Weight
- 261 KB
- Volume
- 34
- Category
- Article
- ISSN
- 1615-9306
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✦ Synopsis
Abstract
In this study, the organochlorine pesticides (OCPs) levels in lake and tap water samples were determined by a dispersive liquid–liquid microextraction method using a low‐density organic solvent and an improved solvent collection system (DLLME‐ISCS). This method used a very small volume of a solvent of low toxicity (11 μL of 1‐nonanol and 400 μL of methanol) to extract OCPs from 10 mL water samples prior to the analysis by GC. After centrifugation in the dispersive liquid–liquid microextraction, there was a liquid organic drop floating between the water surface and the glass wall of the centrifuge tube. The liquid organic drop (with some water phase) was transferred into a microtube (3 mm×15 mm) with a syringe. The organic and aqueous phases were separated in the microtube immediately. Then, 1 μL of the organic solvent (which was in the upper portion of liquid in the microtube) was easily collected by a syringe and injected into the GC‐ECD system for the analysis. Under optimum conditions, the linear range of this method was 5–5000 ng/L for most of the analytes. The correlation coefficient was higher than 0.997. Enrichment factors ranged from 1309 to 3629. The relative recoveries ranged from 73 to 119% for lake water samples. The LODs of the method ranged from 0.7 to 9.4 ng/L. The precision of the method ranged from 1.0 to 10.8% for lake water.