Determination of manganese at ng ml levels in natural waters by differential pulse polarography.

A procedure based on differential pulse polarography is described for the determination of manganese at ng ml levels in fresh, estuarine and sea-water buffered at pH 9.5 with a citrate-borate solution that also serves as supporting electrolyte. The procedure is unaffected by the potentially interfering compounds most likely to occur in natural waters. Furthermore, iron (in ascorbate-borate buffer, pH 9.5) or chromium (in ascorbate-ammonia-ammonium-chloride buffer, pH 9.8) can be determined together with manganese. Some results for the concentration of manganese, iron and chromium in the River Arno are reported.