Rapid determination of total mercury in treated waste water by cold vapor atomic absorption spectrometry in alkaline medium with sodium hypochlorite solution.

Addition of a sodium hypochlorite solution (9.2% (w/v)) was effective to reduce a sulfide interference in determination of organic mercury, including methylmercury and phenylmercury, as well as a previously reported determination of inorganic mercury by cold vapor atomic absorption spectrometry (CVAAS) in an alkaline medium. Total mercury ranging from 0.17 to 33mugL(-1) in 15mL of sample solutions containing up to 200mgL(-1) of sulfide can be determined without any serious interference by sulfide when 1mL of the sodium hypochlorite solution was added after dilution of the sample solution to 25mL. The proposed method was simple and rapid because no digestion processes were required for the determination of total mercury; the time required for the determination was only about 5min. The proposed method was applicable to the analysis of treated waste water.