GB/T 32696-2016 Photography.Determination of residual thiosulfate and other related chemicals in processed photographic materials.Methods using iodine-amylose, methylene blue and silver sulfide (English Version)
General Administration of Quality Supervision, Inspection and Quarantine of the People‘s Republic of China
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GB/T 32696-2016
Scope
This standard gives a detailed description on how to determine the residues of thiosulfate and other related chemicals in processed photographic materials. This standard applies to gelatin silver halide products that are finally fixed with thiosulfate and washed with water. This standard does not apply to stabilized black and white products, heat-processed films, or snapshot-type products. The procedure given in this standard is used to detect residual thiosulfate, and the silver densitometer method can also measure residual related polysulfate species. The measurement procedures described in this standard are limited by the stability of the processed photographic material, the limitations of which are described in Appendices A and B. Use the iodine-amylose method or the methylene blue method to determine the residual thiosulfate content. For films or dry plates with photographic photosensitive layers on both sides or with a photosensitive layer on one side and a gelatin backing layer on the opposite side, after processing The amount of thiosulfate contained was about twice that of the sample coated on only one side. The iodine-amylose method can be used for barium ground photographic paper, plastic-coated photographic paper, film and dry plate. This method is used for films and papers that contain a developer. The methylene blue method can be used for barium ground photo paper, plastic-coated photo paper, film and dry plate, but not for film and photo paper containing developer. Silver sulfide density method measures thiosulfate, polythionate and all other residual chemicals in products that can chemically react with silver ions to form silver "spots" under specific test conditions. See Appendix B for method summary, scope, etc. in tabular form.
ISO 10349-1:1992 Photography; photographic-grade chemicals; test methods; part 1: general
GB/T 32696-2016 history
2016GB/T 32696-2016 Photography.Determination of residual thiosulfate and other related chemicals in processed photographic materials.Methods using iodine-amylose, methylene blue and silver sulfide