scholarly journals Characteristic Redox Potential-Time Curve in the Iron(II)/Nitric Acid Autocatalytic Reaction and Its Application to a Time Measurement-determination of Folic Acid

2008 ◽  
Vol 24 (3) ◽  
pp. 411-414 ◽  
Author(s):  
Jun KATO ◽  
Shukuro IGARASHI
Keyword(s):  
Folic Acid ◽  
Nitric Acid ◽  
Redox Potential ◽  
Time Measurement ◽  
Autocatalytic Reaction ◽  
Time Curve

Determination of subnanogram amounts of sulfur dioxide and sulfites by pneumatopotentiometry

1986 ◽  
Vol 51 (10) ◽  
pp. 2077-2082 ◽  
Author(s):  
Jan Langmaier ◽  
František Opekar
Keyword(s):  
Sulfur Dioxide ◽  
Redox Potential ◽  
Sodium Hydroxide ◽  
Porous Membrane ◽  
Membrane Electrode ◽  
Iodine Monochloride ◽  
Membrane Pores ◽  
Relative Standard ◽  
Limit Of Quantitation

Gold porous membrane electrode has been used for the potentiometric determination of small amounts of sulfur dioxide absorbed in the solutions of sodium tetrachloromercurate or sodium hydroxide. Sulfur dioxide is released by the reaction with an acid into a stream of nitrogen and led to the electrode immersed into the solution of iodine monochloride. Part of SO2 penetrates through the membrane pores into the solution where it is oxidized. The electrode redox potential change is a measure of the SO2 concentration in the absorption solution. In the solution of 1 . 10-5 M[ICl2]- in 0.02 M-HClO4 the limit of quantitation was found to be 0.07 ng SO2 . ml-1. The relative standard deviations of 1.4% and 2.5% were found for the determinations of 10 ng and 0.5 ng of SO2, respectively. Higher concentrations of H2S interfere only in the hydroxide solution. About 10 samples can be analyzed per one hour.

Sign in / Sign up

Export Citation Format

Share Document