A Green Fieldable Analyzer for Arsenic

绿色现场砷分析仪

• 批准号: 0456120
• 负责人: Purnendu Dasgupta
• 金额: $ 35.3万
• 依托单位: Texas Tech University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-02-15 至 2006-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0456120&HistoricalAwards=false
• 关键词: Green; Fieldable; Analyzer; Arsenic

Professor Purnendu Dasgupta of Texas Tech University is supported by the Analytical and Surface Chemistry program to develop a new environmentally friendly tool for the analysis of various arsenic species in groundwater samples and drinking water sources. Most fieldable arsenic detectors involve the use of the toxic chemicals lead and mercury. Further, most test kits are not suitable for analyzing arsenic below 10 microgram/L (the current acceptable level set by WHO), and the method developed in this work will improve this sensitivity. The instrument is based on sequential injection (for speciation), zone fluidics (for hydride generation), and gas phase chemiluminescence (for detection). The integrated arsenic analyzer includes concentration and separation of arsenic species with ion exchange cartridges, electrooxidation of As(III) to As(V), electroreduction of As(V) to arsine with an electrolytic arsine generator, membrane-based electrodialytic salt splitter, and enhanced ozone generation by electrical discharge and oxygen feed. It only requires the use of NaCl and electricity to enable analysis of arsenic at the sub-microgram/L levels. With a preliminary setup, the PI achieved detection limits of around 0.1 ppb using only a 2 mL sample. By adjusting acidity, he can distinguish between arsenic(III) and arsenic(V), and he can detect organic arsenic species. The project includes undergraduates who work on semester-long research modules.Millions of wells around the world may contain high levels of arsenic. However, many of these wells have not been tested. Besides its acute toxicity, it is a known carcinogen, especially arsenic(III). Hence, it is important to monitor the arsenic species, both in groundwater and drinking water treatment facilities. The method being developed here would be applicable to field work, even in rural areas of India and Bangladesh devastated by arsenic poisoning.

德克萨斯理工大学的 Purnendu Dasgupta 教授在分析和表面化学项目的支持下，开发了一种新的环保工具，用于分析地下水样品和饮用水源中的各种砷形态。 大多数现场砷探测器都使用有毒化学物质铅和汞。 此外，大多数检测试剂盒不适合分析低于10微克/升（世界卫生组织设定的当前可接受水平）的砷，而本工作开发的方法将提高这种灵敏度。 该仪器基于顺序注射（用于形态形成）、区域射流（用于氢化物生成）和气相化学发光（用于检测）。集成砷分析仪包括使用离子交换盒浓缩和分离砷物质、将 As(III) 电氧化为 As(V)、使用电解胂发生器将 As(V) 电还原为胂、基于膜的电渗析盐分离器和通过放电和供氧增强臭氧生成。只需使用 NaCl 和电即可分析亚微克/升级别的砷。通过初步设置，PI 仅使用 2 mL 样品即可实现约 0.1 ppb 的检测限。通过调节酸度，他可以区分砷（III）和砷（V），并且可以检测有机砷形态。该项目包括从事为期一个学期的研究模块的本科生。世界各地数百万口井可能含有高浓度的砷。然而，其中许多井尚未经过测试。除了其急性毒性外，它还是一种已知的致癌物质，尤其是砷(III)。因此，监测地下水和饮用水处理设施中的砷形态非常重要。 这里开发的方法将适用于实地工作，甚至适用于遭受砷中毒破坏的印度和孟加拉国的农村地区。