The environmental conditions affecting the growth and multiplication ofLemna paucicostata in the presence of heavy metals were examined to establish a phytometer method for water pollution using the duckweed,Lemna. The pH of the medium, concentration, and composition of the nutrient in the medium, and the temperature at which cultures were maintained, were found to affect the sensitivity ofLemna to heavy metals. Therefore, if the growth and multiplication ofLemna is maintained by a Bonner-Devirian's medium (pH 6.1, 7.1) above 25°C, heavy metals can be detected in water.

Lemna (duckweed) as an indicator of water pollution. I. The sensitivity of Lemna paucicostata to heavy metals

Visual determination of nitrite and nitrate in waters by color band formation method.

Chapter 4 – Tests for the Elements, their Ions and Compounds

Error sources associated with the spectrophotometric determination of low levels (e.g. 90%) of nitrate from the marine lake sediments studied was achieved with 15 min mixing with 0.1 M NH4CI, using a sediment to extractant ratio of 1:30. The nitrate in the extracts was determined by reducing it to nitrite (using Cd powder), with subsequent colour development based on the addition of sulfanilic acid and N-1-naphthyl-ethylenediamine dihydrochloride. The reduction step was sensitive to the experimental conditions used, but was near quantitative using 0.1 M NH4CI extracts. (Much lower transformation levels were observed when the nitrate solutions contained KCI or CaSO4, or when Zn powder was u...

Errors in the determination of low levels of nitrate in lake sediments

Estimation of micro quantities of nitrate in water with a single tablet-formed reagent

Spectrophotometric determination of nitrate ion in the presence of nitrite ion

https://www.jstage.jst.go.jp/article/jswtb1964/14/1/14_1_1/_pdf

Masahiro Morimoto

Papers

Spectrophotometric determination of nitrate ion in the presence of nitrite ion

Growth of Eichhornia crassipes Solms and accumulation of nutrients