Automated method for the determination of total and inorganic mercury in water and wastewater samples

PRESERVATION OF SAMPLES FOR DISSOLVED MERCURY1

“…Lo and Wai (1975) measured a 95-percent loss of 203Hg from a 5pg/L solution after 21 days of storage in a polyethylene container, 77 percent of which was adsorbed on the container walls and 18 percent lost by volatilization. Coyne and Collins (1972) noted up to 40-percent loss of mercury from creek and distilled water within 4 h. El- Awady, et al (1976) noted 20 percent of the mercury in a 3-j.tgfL distilled-water solution was lost within 10 mm of its preparation and 60 percent was lost over a period often days.…”

“…Compounding the problem of preserving mercury in solution is the need for mercury to be in a form that can be reduced and analyzed by cold vapor atomic-absorption spectrometry. Organic mercury must be converted to ionic mercury (El-Awady, et al, 1976), and the method of preservation must not interfere with the reduction of aqueous mercury by stannous chloride during analysis. Only the fraction of reduced mercury that is partitioned to the gas phase is measured by cold vapor atomic-absorption spectrometry (Koirtyohann and Kahlil, 1976).…”

Metals in Sediments

“…[48][49][50][51][52][53][54][55] Iskander et al 43 applied flameless atomic absorption to a sulfuric acid-nitric acid digest of the sample following reduction with potassium permanganate, potassium persulfate, and stannous chloride. [48][49][50][51][52][53][54][55] Iskander et al 43 applied flameless atomic absorption to a sulfuric acid-nitric acid digest of the sample following reduction with potassium permanganate, potassium persulfate, and stannous chloride.…”

Quality-assurance data for routine water analysis in the laboratories of the US Geological Survey; 1981 annual report

“…Another partial explanation may result from the use of nitric acid as the singular preservation agent used by the Survey. Several investigators have shown that nitric acid alone is insufficient for the preservation of mercury in dilute solutions (El-Awady, Miller and Carter, 1976;Feldman, 1974). Most samples failing the precision test and not containing SRWS 73 had values that were less than the MPV.…”