1、BRITISH STANDARD BS ISO 7766:2003 Processing photographic wastes Analysis of cyanides Determination of hexacyanoferrate(II) and hexacyanoferrate(III) by spectrometry ICS 13.030.30; 37.040.30 BS ISO 7766:2003 This British Standard was published under the authority of the Standards Policy and Strategy
2、 Committee on 30 June 2003 BSI 30 June 2003 ISBN 0 580 42166 X National foreword This British Standard reproduces verbatim ISO 7766:2003 and implements it as the UK national standard. It supersedes BS ISO 7766-1:1993 which is withdrawn. The UK participation in its preparation was entrusted to Techni
3、cal Committee CPW/42, Photography, which has the responsibility to: A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international publications referred to in this document may be found in the BS
4、I Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for
5、its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK inter
6、ests informed; monitor related international and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an inside front cover, the ISO title page, pages ii to v, a blank page, pages 1 to 7 and a back cover. The BSI copyright date displayed in thi
7、s document indicates when the document was last issued. Amendments issued since publication Amd. No. Date Comments Reference number ISO 7766:2003(E)INTERNATIONAL STANDARD ISO 7766 First edition 2003-06-15 Processing photographic wastes Analysis of cyanides Determination of hexacyanoferrate(ll) and h
8、exacyanoferrate(lll) by spectrometry Effluents de traitement photographiques Analyse des cyanures Dtermination de lhexacyanoferrate(ll) et de lhexacyanoferrate(lll) par spectromtrie BSISO7766:2003ii BSISO7766:2003 iiiContents Page Foreword iv Introduction v 1 Scope 1 2 Normative references . 1 3 Saf
9、ety and operational precautions 1 4 Principle . 2 5 Reactions . 3 6 Reagents and materials 3 7 Apparatus. 4 8 Sampling and sample preparation 4 9 Procedure. 5 10 Expression of results 6 11 Test report 6 Bibliography . 7 BSISO7766:2003iv Foreword ISO (the International Organization for Standardizatio
10、n) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be rep
11、resented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards a
12、re drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an Internatio
13、nal Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 7766 was pre
14、pared by Technical Committee ISO/TC 42, Photography. BSISO7766:2003 vIntroduction This International Standard is devoted to the analysis of photographic wastes; it encompasses the analysis of complexed iron cyanides (hexacyanoferrates) in photographic effluents. Some of the chemicals specified in th
15、e test procedures are caustic, toxic, or otherwise hazardous. Specific warning, caution and danger notices are noted but, in addition, the normal precautions required during the performance of any chemical procedure should be exercised at all times. In the case of effluents, the photographic laborat
16、ory can best establish conformity to regulations by appropriate chemical analysis. In some cases, in-house analyses will be possible; but the use of an outside laboratory will often be required. Complexed cyanides are used in the bleaching stage of colour photographic processing and it is, therefore
17、, possible for the cyanide portion of the resulting photographic effluent to reach a reportable level. Complexed cyanides contribute to the total cyanides in those tests in which the sample preparation breaks down the complexed cyanides. It is the purpose of this International Standard to provide a
18、method giving an independent determination of the cyanide present as hexacyanoferrate complexes. Due to the chemical behaviour of cyanide complexes, it is not possible to specify a single method for the quantitative determination of complexed cyanides in these effluents. The analysis of cyanide is c
19、overed in various aspects in the following International Standards: ISO 6703-1:1984, Water quality Determination of cyanide Part 1: Determination of total cyanide; ISO 6703-2:1984, Water quality Determination of cyanide Part 2: Determination of easily liberatable cyanide. NOTE 1 Easily liberatable c
20、yanides are defined as substances with cyanide groups and a measurable hydrocyanic acid vapour pressure at pH 4 and room temperature. NOTE 2 Cyanide diffuses as hydrogen cyanide (HCN) at room temperature from a solution at pH 6; the procedure determines cyanide from simple compounds of cyanide and e
21、asily dissociated complexes. BSISO7766:2003blankINTENRATIONAL TSANDADR IS:6677 O3002(E)I SO 3002 All irhgts seredevr 1Processing photographic wastes Analysis of cyanides Determination of hexacyanoferrate(ll) and hexacyanoferrate(lll) by spectrometry 1 Scope This International Standard establishes a
22、test method for the determination of hexacyanoferrate(II) (ferrocyanide) and hexacyanoferrate(III) (ferricyanide), referred to hereafter as Fe(CN) 6 , in photographic processing effluents 1) . Results are reported as hexacyanoferrate, Fe(CN) 6 . 2 Normative references The following referenced docume
23、nts are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 5667-1:1980, Water quality Sampling Part 1: Guidance on the design of sampli
24、ng programmes ISO 5667-2:1991, Water quality Sampling Part 2: Guidance on sampling techniques ISO 5667-3:1994, Water quality Sampling Part 3: Guidance on the preservation and handling of samples ISO 6353-1:1982, Reagents for chemical analysis Part 1: General test methods ISO 6353-2:1983, Reagents fo
25、r chemical analysis Part 2: Specifications First series ISO 6353-3:1987, Reagents for chemical analysis Part 3: Specifications Second series ISO 10349-1:2002, Photography Photographic-grade chemicals Test methods Part 1: General 3 Safety and operational precautions 3.1 Hazard warnings Some of the ch
26、emicals specified in the test procedures are caustic, toxic, or otherwise hazardous. Safe laboratory practice for the handling of chemicals requires the use of safety glasses or goggles and, in some cases, other protective apparel such as rubber gloves, face masks and aprons. Specific danger notices
27、 are given in the text for particularly dangerous materials, but normal precautions are required during the performance of any chemical procedure at all times. 1) Significant levels of thiosulfate (hypo) can result in interference. Significant levels of thiosulfate in processing-machine effluents re
28、sult in oxidation of the thiosulfate by iron (III). Sulfur will form, increasing the spectrophotometric absorbance which is measured. Also, thiosulfate may deplete the added iron (III) leaving nothing for the colour reaction. The method is applicable to effluents from buildings where the thiosulfate
29、 would be diluted by the rest of the building wastes and this would eliminate the interference. BSISO7766:20031ISO 7766:2003(E) 2 I SO 3002 All irhgts seredevrThe first time that a hazardous material is noted in the test procedures, the hazard will be indicated by the word “DANGER” followed by a sym
30、bol consisting of angle brackets “ ” containing a letter that designates the specific hazard. A double bracket “ ” will be used for particularly perilous situations. In subsequent statements involving handling of these hazardous materials, only the hazard symbol consisting of the brackets and letter
31、(s) will be displayed. Furthermore, for a given material, the hazard symbol will be used only once in a single paragraph. Hazard warning symbols will not be used for common organic solvents when used in quantities of less than 1 l, unless they are particularly hazardous. Detailed warnings for handli
32、ng chemicals and their diluted solutions are beyond the scope of this International Standard. Employers shall provide training and health and safety information in accordance with legal requirements. The hazard code system used in this International Standard is intended to provide information to the
33、 users and is not meant for compliance with any legal requirements for labelling, as these vary from country to country. It is strongly recommended that anyone using these chemicals obtain pertinent information from the manufacturer about the hazards, handling, use and disposal of these chemicals. 3
34、.2 Hazard information code system B Harmful if inhaled. Avoid breathing dust, vapour, mist or gas. Use only with adequate ventilation. C Harmful if contact occurs. Avoid contact with eyes, skin or clothing. Wash thoroughly after handling. F Will burn. Keep away from heat, sparks and open flame. Use
35、with adequate ventilation. O Oxidizer. Contact with other material may cause fire. Do not store near combustible materials. S Harmful if swallowed. Wash thoroughly after handling. If swallowed, obtain medical attention immediately. S May be fatal if swallowed. If swallowed, obtain medical attention
36、immediately. 3.3 Safety precautions ALL PIPETTE OPERATIONS SHALL BE PERFORMED WITH A PIPETTE BULB OR PLUNGER PIPETTE. Failure to observe this warning notice can result in cyanide poisoning. THIS IS A CRITICAL SAFETY WARNING! Digestion procedures shall be performed in a fume hood. Hydrogen cyanide or
37、 other toxic substances may be evolved. Safety glasses shall be worn for all laboratory work. 4 Principle A sample of effluent, or diluted effluent, is treated with a mixture of iron(II) and iron(III) ions. If Fe(CN) 6 is present, a blue suspension will form. In the range 1,0 mg/l to 10,0 mg/l of Fe
38、(CN) 6 , this suspension is stable and its absorbance is linear with its concentration. The absorbance is measured with a spectrometer, and the concentration determined from a previously established calibration. BSISO7766:20032ISO 7766:2003(E) I SO 3002 All irhgts seredevr 35 Reactions 3Fe(II)(CN) 6
39、 4+ 4Fe 3+ Fe 4 Fe(CN) 6 32Fe(III)(CN) 6 3+ 3Fe 2+ Fe 3 Fe(CN) 6 26 Reagents and materials 6.1 General 6.1.1 Handling and labelling Reagents shall be handled in accordance with health and safety precautions as shown on containers, or as given in other sources of such information. Proper labelling of
40、 prepared reagents includes chemical name, date of preparation, expiration date, restandardization date, name of preparer and adequate health and safety precautions. The discharge of reagents shall conform to applicable environmental regulations. 6.1.2 Purity Reagents used in the test procedures sha
41、ll be certified reagent-grade chemicals and shall meet appropriate standards or be chemicals of a purity acceptable for the analysis, as specified in ISO 6353-1, ISO 6353-2 and ISO 6353-3. 6.1.3 Water Whenever water is specified without other qualifiers in the test procedures, only distilled water o
42、r water of equal purity shall be used. 6.1.4 Strength of solutions 6.1.4.1 Acids and ammonium hydroxide are full strength unless otherwise specified. 6.1.4.2 When a standardized solution is required, its concentration is expressed as molarity (mol/l). The number of significant figures to which the m
43、olarity is known shall be sufficient to ensure that the reagent does not limit the reliability of the test method. 6.1.4.3 When a standardized solution is not required, its concentration is expressed, in grams per litre (g/l), to the appropriate number of significant figures. 6.1.4.4 When a solution
44、 is to be diluted, its dilution is indicated by (X + Y), meaning that X volumes of reagent, or concentrated solution, are to be diluted with Y volumes of water (6.1.3). 6.2 Reagents 6.2.1 Ferrous-ferric reagent Dissolve with continuous stirring, using a magnetic stirrer, 0,75 g of iron(II) chloride
45、tetrahydrate (FeCl 2 4H 2 O), 0,75 g of iron(III) chloride hexahydrate (FeCl 3 6H 2 O) and 3 ml of concentrated hydrochloric acid (6.2.2) (DANGER: B, C) in 20 ml of water contained in a 50 ml beaker. Dilute to 30 ml. BSISO7766:20033ISO 7766:2003(E) 4 I SO 3002 All irhgts seredevr6.2.2 Hydrochloric a
46、cid (HCI), concentrated 1,18 g/ml (DANGER: B, C) 6.2.3 Hydrochloric acid solution, 1 mol/l To about 500 ml of water in a 1 l beaker, add 31 ml of concentrated hydrochloric acid (6.2.2) (B, C) with constant stirring. Dilute to 1 l with water. 6.2.4 Potassium ferrocyanide standard solution, correspond
47、ing to 0,040 g/l of Fe(CN) 6Prepare a solution containing 4,0 g/l of Fe(CN) 6 by adding 8,0 g of potassium ferrocyanide trihydrate K 4 Fe(CN) 6 3H 2 O (DANGER: S) to a 1 l one-mark volumetric flask. Add water to dissolve and make up to the mark. Pipette 10 ml of this solution into a 1 l one-mark vol
48、umetric flask. Make up to the mark with water. This solution contains 0,040 g/l of Fe(CN) 6 . This dilute standard solution should be prepared fresh daily. 6.2.5 Sodium hydroxide solution, 100 g/l Slowly add 100 g of sodium hydroxide pellets (DANGER: C) to 800 ml of cold water in a 2 l container. Ex
49、treme caution shall be exercised in this operation as considerable heat will be evolved. The procedure should be carried out under an exhaust hood. It is also advisable to place the container in a polyethylene pail. Stir until dissolved, cool and dilute to 1 l. This concentration is not critical. 6.3 Materials 6.3.1 Filter paper, pre-folded, medium porosity (8 m par
