Continuous amperometric sampling process - for determining nitrate-nitrite concns. in aq. media, using a redn. column contg. zinc-based metallic granules

摘要

Continuous amperometric sampling process for nitrates and/or nitrates in aq. soln., in which: (a) the sample's aq. medium is constantly mixed with a conditioning soln. to obtain a conditioned sample; (b) this conditioned sample is then put in an amperometric measuring cell which delivers a signal indicating the nitrate/nitrite concn.; (c) with nitrate samples, before stage (b) the conditioned sample is passed through a redn. column to reduce the nitrates to nitrites. Also claimed is a device for carrying out the process, comprising: means for feeding in (1) and conditioning (2,3,10,12,17) the sample (14); a redn. column (6) filled with means of reducing nitrates to nitrites, located downstream of the means conditioning; an amperometric measuring cell (8) with a temp. probe and means of converting the measurements to nitrate/nitrite concentration. The redn. column contains zinc-based metallic granules, and the conditioning soln. is a weak acid. USE/ADVANTAGE - The continuous determination of nitrate concentrations in water flow sinto and out of factories. Nitrate concns. are a good indicator of general organic pollution. The effective redn. of nitrates to nitrites before the amperometric analysis is carried out, using simple, viable and economical means with minimal toxicity.