High sensitivity arsenic analyzer based on liquid-reagent-free hydride generation and chemiluminescence detection for on-site water analysis.

In this work, a portable and reliable instrument based on manual hydride generation and subsequent ozone induced chemiluminescence analysis was developed and optimized for measurement of aqueous arsenic in drinking water. The aim was to develop a system for use in the field in villages in developing countries where water treatment systems have been installed. Consequently, it is beneficial that the system could be operated without reagent solutions or purified water. Arsenic trihydride (arsine) was generated by reaction with solid acid and solid borohydride, and then introduced to a chemiluminescence cell where the arsine was mixed with ozone to generate chemiluminescence. The measurement could be repeated with the throughput of 60 times h(-1), and the limit of detection was 0.4 µg L(-1). The measurable arsenic concentration was up to 1 mg L(-1) for 2 mL samples. The system was evaluated for analysis of natural water samples, and the obtained data agreed well with those from ICP-MS and sequential hydride generation flow analysis. We expect this small and inexpensive instrument will be used in developing countries.