2段階液/液抽出法による水中のダラポンのLC/MS分析 LC/MS Analysis of Dalapon in Water using Two-step Liquid-liquid Extraction
A simple pre-concentration method of dalapon (2,2-dichloropropionic acid) in water for LC/MS analysis by two-step liquid-liquid extraction is proposed. Dalapon was extracted from 200 m<i>l</i> of water sample containing 2 m<i>l</i> of sulfuric acid and 80 g of sodium chloride into 10 m<i>l</i> of methyl-<i>t</i>-butyl ether (MTBE). Then, dalapon was back-extracted from 5 m<i>l</i> portion of the MTBE extract into 1 m<i>l</i> of aqueous solution (water, several concentrations of sodium hydroxide solution or phosphate buffer solution). An aliquot of the aqueous phase was directly injected to LC/MS apparatus. Recovery of dalapon depended on equilibrium pH after the second step extraction. The best recovery was observed in the pH range from 6 to 8. When the phosphate buffer solution (pH 6.87) was used as the aqueous phase in the second step extraction, no change in the pH value of the aqueous phase was observed between before and after extraction. Therefore, phosphate buffer solution was suitable for the second step extraction.<br>The recovery of dalapon (0.0008 mg/<i>l</i>) by the proposed method was about 120 % and the relative standard deviation of five replicate runs was below 3 %. This method is satisfactorily applicable to LC/MS analysis of detection limit of dalapon (0.0008 mg/<i>l</i>) in tap water provided by the Ministry of Health Labour and Welfare of Japan.
- 環境化学 : journal of environmental chemistry
環境化学 : journal of environmental chemistry 17(1), 53-58, 2007-03-25
Japan Society for Environmental Chemistry