Overview
ISO 10349-2:1992 specifies a laboratory test method for the determination of matter insoluble in water in photographic‑grade chemicals. The procedure defines how to transfer a test portion into water, extract soluble material by heating, collect insoluble residue on a porous filter crucible, dry and reweigh the residue, and calculate the percentage of insoluble matter. This part is intended to ensure the purity and performance of chemicals used in photographic processes.
Key topics and requirements
- Scope: A general method for measuring water‑insoluble matter in photographic chemicals.
- Apparatus:
- Oven capable of maintaining 105 °C to 115 °C.
- Porous filter crucible with 10 µm to 15 µm retention.
- Procedure (as specified in the standard):
- Place the specified test portion in a 125 ml conical flask containing 100 ml of water.
- Heat on a steam bath for 30 minutes.
- Filter through a dry porous crucible (10 µm–15 µm retention) and wash with hot water.
- Dry the crucible plus residue at 105 °C for 4 hours, then reweigh.
- Calculation: Express the content of insoluble matter as a percentage by mass using the masses:
- m0 = mass of test portion (g)
- m1 = mass of empty crucible (g)
- m2 = mass of crucible + residue after drying (g)
- Percentage insoluble = ((m2 − m1) / m0) × 100%
- Test report: Must specify method used, the numerical result, sample identification, and any deviations or incidents affecting results.
Applications and who uses it
- Quality control laboratories in photographic chemical manufacturing to verify product purity.
- Incoming inspection for chemical suppliers and procurement teams assessing conformance to specifications.
- Analytical and testing laboratories performing routine photography chemical tests to prevent particulate contamination that can cause image defects.
- Conservation and restoration labs that evaluate chemical reagents for film processing or photographic material treatment.
Practical value
- Ensures consistency and reliability of photographic developers, fixers, and other reagents by quantifying insoluble contaminants.
- Helps prevent processing defects such as spots, streaks or uneven development caused by particulate matter.
- Supports compliance with product specifications and facilitates supplier qualification and batch release.
Related standards
- ISO 10349-1:1992 - Photography - Photographic‑grade chemicals - Test methods - Part 1: General (reagents, glassware, hazard codes).
- Other parts in the ISO 10349 series cover residuals, heavy metals, halides, alkalinity, volatile matter and additional analytes (Parts 3–12).
Keywords: ISO 10349-2, photographic-grade chemicals, test methods, determination of matter insoluble in water, filter crucible, quality control, photography.