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教授得到了分析和表面化学项目的支持，开发了一种新的环保工具，用于分析地下水样本和饮用水源中的各种砷。大多数可用于现场的砷探测器都涉及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（世卫组织目前设定的可接受水平）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（用于物种形成），区域流体（用于氢化物生成）和气相化学发光（用于检测）。集成的砷分析仪包括用离子交换盒进行砷的浓度和分离，用电解砷发生器将As（III）电氧化为As(V)，用电解砷发生器将As(V)电还原为砷，薄膜电析盐分离器，以及通过放电和供氧来增强臭氧的产生。它只需要使用NaCl和电就可以分析亚微克/升水平的砷。通过初步设置，PI仅使用2ml样品即可达到约0.1 ppb的检测限。通过调节酸度，他可以区分砷（III）和砷(V)，他可以检测有机砷的种类。该项目包括从事一学期研究模块的本科生。全世界数以百万计的水井可能含有高浓度的砷。然而，其中许多井尚未进行测试。除了它的急性毒性，它是一种已知的致癌物，特别是砷（III）。因此，监测地下水和饮用水处理设施中砷的种类是很重要的。这里正在开发的方法将适用于实地工作，甚至适用于受砷中毒影响的印度和孟加拉国农村地区。