Determination of Nitrite With A Ptfe-Membrane, Covered Electrode After Reduction To Nitrogen Oxide, In A Reagent Saving Flow Injection System

Autor: Motohiko Hikuma, Hiroyuki Kobayashi
Rok vydání: 2000
Předmět:
Zdroj: Analytical Letters. 33:1013-1023
ISSN: 1532-236X
0003-2719
Popis: Nitrite was reduced in acidic potassium iodide solution to produce nitrogen oxide which was measured amperometrically by a modified gold electrode covered with a PTFE-membrane as the permeability barrier for interfering substances in the sample. The calibration curve was linear up to 30 μM of nitrite and 10 samples could be determined per hour. The average current and the standard deviation for 10 μM standard solution (N=10) were 1.51 x 10-2 μA and 6.4 x 10-5 μA (RSD=0.42 %), respectively. The detection limit was 0.25 μM. No response was observed for electrochemical interferant substances such as ascorbic acid and FeSO4. The reducing reagent could be reused. Recovery tests were satisfactory (101-103%). The results obtained with this sensor and with the diazotization method for a fish culture water agreed within 8.6%.
Databáze: OpenAIRE