Showing papers on "Amperometry published in 1979"

Amperometric estimation of BOD by using living immobilized yeasts

Abstract: A microbial electrode consisting of immobilized living whole cells of yeasts, porous membrane and an oxygen electrode was prepared for continuous estimation of biochemical oxygen demand (BOD). Immobilized Trichosporon cutaneum was employed for the microbial electrode sensor for BOD. When a sample solution containing the equivalent amount of glucose and glutamic acid was injected into the sensor system, the current of the electrode decreased markedly with time until steady state was reached. The response time was within 18 min. A linear relationship was observed between the current decrease and the concentration below 41 mg l − of glucose and 41 mg l − glutamic acid (5-day BOD 60 mg l −). The current decrease was reproducible within ± 6% of the relative error when a sample solution containing 27 mg l − of glucose and 27 mg l − of glutamic acid (5-day BOD 40 mg l −) was employed. The microbial electrode sensor was applied to untreated waste waters from a fermentation factory. Good comparative results were obtained between BOD estimated by the microbial electrode and that determined by the conventional 5-day method (regression coefficient was 1.2). Furthermore, the effect of various compounds on BOD estimation was also examined. The current output of the microbial electrode sensor was almost constant for 17 d and 400 tests.

Cation Exchange Liquid Chromatography with Amperometric Detection as a Method for the Analysis of Endogenous Catecholamine Concentrations in Plasma or Serum

Abstract: A chromatographic system which permits determination of catecholamines, isolated from a few ml of plasma or serum, is described in detail. Some factors of importance for the improvement of the signal-to-noise ratio at subpicomole detection levels have been carefully investigated.

Kinetics of cobalt(III)+ iron(II) reaction by platinum-electrode chronoamperometry in aqueous perchloric acid solution

Abstract: The rate of the CoIII+ FeII reaction in 3 mol dm–3 HClO4 is obtained by amperometry and confirms (corrected) results from stopped-flow experiments. Three current questions about the state and reactivity of CoIII are discussed and partly resolved; in particular E° for CoIII/CoII is confirmed as being 1.8–1.9 V.

Kinetics of cobalt(iii) + iron(ii) reaction by platinum-electrode chronoamperometry in aqueous perchloric acid solution

Abstract: The rate of the CoIII+ FeII reaction in 3 mol dm–3 HClO4 is obtained by amperometry and confirms (corrected) results from stopped-flow experiments. Three current questions about the state and reactivity of CoIII are discussed and partly resolved; in particular E° for CoIII/CoII is confirmed as being 1.8–1.9 V.