ISO 3626:1996 download.Fluid power systems 0-rings Part 1: Inside diameters, cross-sections, tolerances and designation codes TECHNICAL CORRIGENDUM 1.
Introduction
0.1 ISO 3626 is one of a series that establishes criteria of purity for chemicals used in processing photographic materials. General test methods and procedures cited in ISO 3626 are compiled in parts 1. 5 and 6 of ISO 10349.
ISO 3626 is intended for use by individuals with a working knowledge of analytical techniques, which may not always be the case. Some of the procedures utilize caustic, toxic or otherwise hazardous chemicals. Safe laboratory practice for the handling of chemicals requires the use of safety glasses or goggles, rubber gloves and other protective apparel such as face masks or aprons where appropriate. Normal precautions required in the performance of any chemical procedure are to be exercised at all times but care has been taken to provide warnings for hazardous materials. Hazard warnings designated by a letter enclosed in angle brackets N( )W are used as a reminder in those steps detailing handling operations and are defined in ISO 10349-1. More detailed information regarding hazards, handling and use of these chemicals may be available from the manufacturer.
0.2 ISO 3626 provides chemical and physical requirements for the suitability of a photographic-grade chemical. The tests correlate with undesirable photographic effects. Purity requirements are set as low as possible consistent with these photographic effects. These criteria are considered the minimum requirements necessary to assure sufficient purity for use in photographic processing solutions. except that if the purity of a commonly available grade of chemical exceeds photographic processing requirements and if there is no economic penalty in its use, the purity requirements have been set to take advantage of the availability of the higher-quality material. Every effort has been made to keep the number of requirements to a minimum. Inert impurities are limited to amounts which will not unduly reduce the assay. All tests are performed on samples as received to reflect the condition of materials furnished for use. Although the ultimate criterion for suitability of such a chemical is its successful performance in an appropriate use test, the shorter, more economical test methods described in ISO 3626 are generally adequate.
Assay procedures have been included in all cases where a satisfactory method is available. An effective assay requirement serves not only as a safeguard of chemical purity but also as a valuable complement to the identity test. Identity tests have been included whenever a possibility exists that another chemical or mixture of chemicals could pass the other tests.
All requirements listed in clause 4 are mandatory. The physical appearance of the material and any footnotes are for general information only and are not part of the requirements.
ISO 3626 establishes criteria for the purity of photographic-grade potassium thiocyanate and specifies the test methods to be used to determine the purity.
2 Normative references
The following standards contain provisions which, through reference in this text, constitute provisions of ISO 3626. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on ISO 3626 are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards.
ISO 10349-1:1992, Photography — Photographic-grade chemicals — Test methods — Part 1: Genera!.
ISO 10349-5:1992, Photography — Photographic-grade chemicals — Test methods — Part 5: Determination of heavy metals and iron content.
ISO 10349-6:1992, Photography — Photographic-grade chemicals — Test methods — Part 6: Determination of halide content.
Weigh. to the nearest 0,001 g, a test portion of about 0.3 g and dissolve it in 50 ml of water. Add 5 ml of the nitric acid (7.1.2.1). followed by 50,00 ml of the silver nitrate (7.1.2.3) using the pipette (7.1.3.2). Shake well, add 2 ml of the ammonium iron(lll) sulfate (7.1.2.2) and titrate the excess of silver nitrate with the ammonium thiocyanate (7.1.2.4) to a permanent red endpoint.
7.1.5 Expression of results
The assay, expressed as a percentage by mass of KCNS, is given by
9,7l8(50-c — Vc2)/m
where
Cl is the actual concentration, in moles per litre, of the silver nitrate (7.1.2.3);
c2 is the actual concentration, in moles per litre, of the ammonium thiocyanate (7.1.2.4);
V is the volume, in millilitres, of the ammonium thiocyanate (7.1.2.4) used for the titration;
m is the mass, in grams, of the test portion;
50 is the volume, in millilitres, of silver nitrate added (7.1.4);
9,718 is the conversion factor obtained from the mass of potassium thiocyanate equivalent to 1 mole of silver
nitrate (i.e. 97,18) x the conversion factor for millilitres to litres (i.e. 0.001) x 100 (for percentage).
7.4 Halide content (as Cli
7.4.1 Specification
Iviaximum content of halide shall be 0.05 % (rn/rn) 10,1 % (rn/rn) as KCIj.
7.4.2 Reagents
7.4.2.1 Sodium hydroxide, solid (DANGER: ((C))).
7.4.2.2 Hydrogen peroxide (H202), 67 g/l (approx.) solution.
Dilute 1 volume of 30 % hydrogen peroxide (DANGER: ((C))(O)) with 4 volumes of water.
7.4.3 Procedure
Weigh, to the nearest 0,1 g, a test portion of about 1 g and dissolve it in 30 ml of the hydrogen peroxide (7.4.2.2). Add 1 g of sodium hydroxide (7.4.2.1) (DANGER: ((C))) and swirl until the vigorous reaction ceases. Add another 30 ml of hydrogen peroxide (7.4.2.2) and boil for 2 mm. Cool and dilute to 100 ml with water. Use a 10 ml aliquot of this test solution. Continue the procedure in accordance with ISO 10349-6:1992. clause 4, using 5 ml of the halide standard solution A.
7.6.1.2.4 Silver nitrate, standard volumetric solution of 0,001 mol/l (0,170 g/l) 2)3)
7.6.1.3 Apparatus
7.6.1.3.1 Two matched Nessler colour-comparison cylinders, of 50 ml capacity.
7.6.1.4 Procedure
Weigh, to the nearest 0,01 g, a test portion of about 1 g and dissolve it in 25 ml of water. Add this solution to a mixture of 20 ml of ammonium hydroxide (7.6.1.2.2) (DANGER: (CXB)) and 2 ml of the silver nitrate (76.1.2.3).
Also prepare a control by adding 1 ml of sulfide standard (7.6.1.2.1) to a mixture of 20 ml of water, 20 ml of ammonium hydroxide (7.6.1.2.2) and 3 ml of 0,001 moth silver nitrate (7.6.1.2.4). Heat both solutions in a boiling water bath for 15 mm. Cool, transfer to the Nessler colour-comparison cylinders (7.6.1.3.1) and dilute to 50 ml.
Compare the colours produced in the two Nessler colour-comparison cylinders. Any colour produced in the sample shall not exceed that produced in the sulfide standard control.
CAUTION — Dispose of all test solutions and rinse all used apparatus immediately. Explosive compounds may be formed on standing.
7.8.2.5 Sodium diethyldithiocarbamate. 1 g/l solution. Freshly prepare as needed.
7.8.3 Apparatus
7.8.3.1 Two matched Nessler colour-comparison cylinders, of 50 ml capacity.
7.8.4 Procedure
Weigh, to the nearest 0.1 g, a test portion of about 10 g and dissolve it in about 25 ml of water in one of the Nessler colour-comparison cylinders (7.8.3.1). Transfer 1 ml of the diluted standard copper solution (7.8.2.4) to the other Nessler colour-comparison cylinder and add about 20 ml of water. To each cylinder, add 1 ml of the citric acid solution (7.8.2.1), 1 ml of the gum arabic solution (7.8.2.3) and sufficient ammonium hydroxide solution (7.8.2.2) to bring the pH to 9 (use pH indicator paper). Dilute each to 50 ml, add 2 ml of the freshly prepared sodium diethyldithiocarbamate solution (7.8.2.5), mix well and allow to stand for 2 mm.
Compare the colours produced in the two cylinders. The test sample turbidity shall not be greater than that of the reference sample.