ISO 10349-3:1992

Overview

ISO 10349-3:1992 - Photography - Photographic-grade chemicals - Test methods - Part 3: Determination of matter insoluble in ammonium hydroxide solution describes a laboratory test to quantify the fraction of a photographic-grade chemical that is insoluble in ammonium hydroxide. The method isolates precipitated calcium, magnesium and ammonium hydroxides, then determines their mass after ignition. This standard supports quality control and chemical analysis in photographic materials and related industries.

Key topics and requirements

• Scope: General test method to determine matter insoluble in ammonium hydroxide solution for photographic-grade chemicals.
• Test portion and dissolution: Weigh a test portion of 10.0 g ± 0.1 g and dissolve in 75 ml of water.
• Reagents (specified concentrations):
  • Ammonium oxalate solution: dissolve 40 g ammonium oxalate monohydrate in 500 ml water and dilute to 1 L.
  • Diammonium hydrogen phosphate solution: dissolve 10 g in 50 ml water and dilute to 100 ml.
  • Ammonium hydroxide solution (1+9): 10 ml NH4OH (ρ = 0.91 g/ml) diluted to 100 ml.
  • Dilute ammonium hydroxide (1+39): 25 ml NH4OH diluted to 1 L.
• Procedure summary:
  • Add 5 ml ammonium oxalate, 4 ml diammonium hydrogen phosphate, and 10 ml ammonium hydroxide to the dissolved sample.
  • Allow to stand at least 8 hours to form precipitate.
  • Filter on ashless filter paper, wash with dilute ammonium hydroxide.
  • Transfer filter with precipitate to a prepared ignition crucible; burn off paper and incinerate residue in a muffle furnace (600 °C ± 50 °C) to constant weight.
  • Cool in a desiccator and reweigh.
• Calculation: Express insoluble matter as percentage by mass using the mass of test portion, crucible, and crucible+residue.
• Apparatus & safety: Requires ignition crucible (porcelain/alumina/platinum/quartz), muffle furnace to 600 °C, ashless filter paper (10–15 µm retention), and desiccator. Follow hazard guidance referenced in ISO 10349-1.

Applications and users

• Quality control laboratories in photographic chemical manufacturing.
• Analytical chemistry labs performing chemical composition and purity testing.
• Conservation and archival labs concerned with chemical contaminants in photographic materials.
• Suppliers and purchasers of photographic-grade chemicals for specification compliance.
• Regulatory or standards bodies assessing conformity of photographic reagents.

Related standards

• ISO 10349-1:1992 - General requirements for photographic-grade chemicals test methods.
• Other parts of ISO 10349 series cover insoluble matter in water, residue after ignition, heavy metals, halide content, alkalinity/acidity, volatile matter, sulfide content, reaction to ammoniacal silver nitrate, specific gravity and density.

Keywords: ISO 10349-3:1992, photographic-grade chemicals, ammonium hydroxide, insoluble matter, test methods, photography, chemical analysis, quality control.