Shinya Mizusawa

False Detection of Cyanide Ion in Photographic Processing Waste Solutions Using Standardized Reference Methods

Abstract Although cyanide compounds are not incorporated in photographic processing solutions, false detection of cyanide ion is often encountered during the determination of total cyanide by various standardized methods such as ISO, ANSI and JIS. Various organic compounds and nitrogen compounds in the processing solutions were examined because of this false detection. The results suggest that hydrogen cyanide is formed by a reaction between these compounds during the distillation process for the separation of total cyanide, even though ISO, ANSI and JIS were used. The results support the following three mechanisms of cyanide formation involved in the process: (1) Hydroxylammonium salts reacts with another ingredient, formaldehyde, to form formaldoxime, which then decomposes to HCN. (2) Hydroxylammonium is oxidized by air to form nitrite ion, which subsequently reacts with organic compounds such as aminocarboxylic acids and aromatic amines (the colour-developing agent) to form HCN. (3) Potassium permangan...

Electrochemical production of the ascorbic acid radical and its in situ detection using uv spectroelectrochemical method

The ascorbic acid radical produced by the anodic oxidation of ascorbic acid was detected by uv absorption using a spectroelectrochemical method during the voltammetric measurement. The radical generation was further confirmed by the measurement of the half-wave potential for the cathodic reduction and the pH dependence of the decay rate using a rotating ring-disc electrode.

Anodic oxidation of hydroquinone in sulfite solution

Abstract The anodic oxidation of hydroquinone in the presence of sulfite was investigated by chronoamperometry at a rotating gold electrode and chronopotentiometry at a stationary gold electrode. The experiments show that sulfite is strongly adsorbed on the electrode inhibiting the hydroquinone oxidation, and at the same time is consumed by sulfonation of the anodic reaction product, p -benzoquinone. The resulting effects can be explained by the respective rates of both processes, depending on the experimental conditions (rotational speed, pH, concentration ratio of reactants).

Analysis of Free Nucleic Acid Bases in Photographic Gelatin by Liquid Chromatography

AbstractA method of liquid chromatography was applied to the analysis offree nucleic acid bases in photographic gelatins. It was possible to analyse free nucleic acid bases in photographic gelatins without any pre-treatment of the sample gelatin solution.Highly restraining gelatins contained free nucleic acid bases, while low restraining or inert gelatins contained little of them. These free nucleic acid bases in gelatins were eliminated by an ion-exchange treatment. The pH dependence of physical retardance was changed by the treatment. The effect of free nucleic acid bases on the physical retardance was proved.

Hardening Reactivity of Amidated Gelatin with Formaldehyde

AbstractThe effects of amidation on the hardening reaction of lime processed gelatin with formaldehyde were studied by measuring the sol fraction and its molecular weight distribution in hardened gelatin films. It was shown that the swelling and sol fraction of the amidated gelatin hardened with formaldehyde was similar to those of acid processed gelatin. However, the molecular weight distribution of the sol fraction from ami-dated gelatin at the initial stage of storage was almost the same as that of the original gelatin and different from that of acid processed gelatin. The hardening reactivity of the amidated gelatin was different from acid processed gelatin.

Physical Developers Including Ascorbic Acid as a Developing Agent

AbstractThe developing action by ascorbic acid (AA) and its combination with hydroquinonc (H2Q) or l-phenyl-3-pyrazolidinone (PHI:) in the post fixation physical developer including thiosulphate or thiocyanate as a complexing agent is discussed. Contrary to the other developing agents (i.e. H2Q, Metol, Kodak CD-3 and PHE), AA showed a greater development rate in the developer including thiosulphate than thiocyanate. The addition of AA to H2Q-thiocyanatc developers brought a retardation effect, while it did not in H2Q-thiosulphate developers. The superadditivity by the PHE-AA combination was observed only in the thiocyanate developer. These behaviours of AA were explained by the inhibition by the oxidation products of AA adsorbed on the development centre and their displacement by thiosulphate.