1、 Reference number ISO 7760:2001(E) ISO 2001INTERNATIONAL STANDARD ISO 7760 Second edition 2001-12-15 Photography Processing waste Determination of hydroquinone Photographie Effluents de traitements Dosage de lhydroquinone ISO 7760:2001(E) PDF disclaimer This PDF file may contain embedded typefaces.
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6、H-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.ch Web www.iso.ch Printed in Switzerland ii ISO 2001 All rights reserved ISO 7760:2001(E) ISO 2001 All rights reserved iiiContents Page Foreword.iv Introduction.v 1 Scope1 2 Normative references1 3 Principle1 4 Reactio
7、ns2 5 Safety and operational precautions.2 6 Materials and reagents3 7 Apparatus.5 8 Sampling and sample preparation.5 9 Procedure.6 10 Expression of results6 11 Test report7 Bibliography8 ISO 7760:2001(E) iv ISO 2001 All rights reserved Foreword ISO (the International Organization for Standardizati
8、on) 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 re
9、presented 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
10、are drafted in accordance with the rules given in the ISO/IEC Directives, Part 3. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting
11、 a vote. Attention is drawn to the possibility that some of the elements of this International Standard may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. International Standard ISO 7760 was prepared by Technical Committee ISO/TC 42,
12、 Photography. This second edition cancels and replaces the first edition (ISO 7760:1986), of which it constitutes a technical revision. ISO 7760:2001(E) ISO 2001 All rights reserved vIntroduction This International Standard is one of a series devoted to the analysis of photographic wastes; it encomp
13、asses the field of analysis of the hydroquinone content in a photographic effluent. This International Standard is intended for use by individuals with a working knowledge of analytical techniques. Some of the procedures use caustic, toxic, or otherwise hazardous chemicals. Safe laboratory practice
14、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, or aprons. Normal precautions for the safe performance of any chemical procedure must be exercised at all times, but specific details have been
15、provided for hazardous materials. Hazard warnings are designated by a letter enclosed in angle brackets “. These are defined in clause 5 and then used throughout the text. More detailed information on hazards, handling, and use of these chemicals may be available from the manufacturer. Photographic
16、laboratories can establish conformity to effluent regulations only by chemical analysis. If this cannot be done in-house, an outside laboratory should be used. INTERNATIONAL STANDARD ISO 7760:2001(E) ISO 2001 All rights reserved 1Photography Processing waste Determination of hydroquinone 1 Scope Thi
17、s International Standard specifies a spectrophotometric method for the determination of hydroquinone in photographic processing waste. This method can be applied to samples containing hydroquinone in the concentration range of 200 g/l to 4 000 g/l; aminophenols and phenylenediamines should also be d
18、etermined by this method. However, sulfonated hydroquinones or products from the further oxidation of benzoquinone will not be determined. 2 Normative references The following normative documents contain provisions which, through reference in this text, constitute provisions of this International St
19、andard. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated
20、 below. For undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain registers of currently valid International Standards. ISO 648:1977, Laboratory glassware One-mark pipettetes. ISO 1042:1998, Laboratory glassware One-mark volumetric flas
21、ks. ISO 5667-1:1980, Water quality Sampling Part 1: Guidance on the design of sampling 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, R
22、eagents for chemical analysis Part 1: General test methods. ISO 6353-2:1983, Reagents for chemical analysis Part 2: Specifications First series. ISO 6353-3:1987, Reagents for chemical analysis Part 3: Specifications Second series. ISO 10349-1:1992, Photography Photographic-grade chemicals Test metho
23、ds Part 1: General. 3 Principle The hydroquinone (together with some other organic compounds) is extracted at a slightly acidic pH from the aqueous sample with 1-pentanol. The extracted hydroquinone is then reacted under alkaline conditions with 1-ethylquinaldinium iodide solution. The absorbance of
24、 the coloured complex that is formed is then measured. ISO 7760:2001(E) 2 ISO 2001 All rights reserved 4 Reactions 5 Safety and operational precautions 5.1 Hazard warnings Some of the chemicals specified in the test procedures are caustic, toxic or otherwise hazardous. Safe laboratory practice for t
25、he 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 are given in the text and footnotes for particularly dangerous materials, but normal precautions are required dur
26、ing the performance of any chemical procedure at all times. The first time that a hazardous material is noted in the test procedures, the hazard will be indicated by the word “DANGER“ followed by a symbol consisting of angle brackets “ “ containing a letter that designates the specific hazard. A dou
27、ble 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(s) will be displayed. Furthermore, for a given material, the hazard symbols will be used only once
28、 in a single paragraph. Hazard warning symbols will not be used for common organic solvents when used in quantities of less than 1 litre, unless they are particularly hazardous. ISO 7760:2001(E) ISO 2001 All rights reserved 3Detailed warnings for handling chemicals and their diluted solutions are be
29、yond the scope of this International Standard. Employers shall provide training and health and safety information in conformance with legal requirements. The hazard code system used in this International Standard is intended to provide information to the users and is not meant for compliance with an
30、y 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. 5.2 Hazard information code system B Harmful if
31、 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 with adequate ventilation. O Oxidizer. Contact
32、 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 immediately. 5.3 Safety precautions ALL PIPETT
33、E OPERATIONS SHALL BE PERFORMED WITH A PIPETTE BULB OR PLUNGER PIPETTE. THIS IS A CRITICAL SAFETY WARNING! Safety glasses shall be worn for all laboratory work. 6 Materials and reagents 6.1 General 6.1.1 Handling and labelling Reagents shall be handled in conformity with health and safety precaution
34、s as shown on containers or as given in other sources of such information. Proper labelling of 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
35、 to applicable environmental regulations. 6.1.2 Purity Reagents used in the test procedures shall be certified reagent-grade chemicals and shall meet appropriate standards or be chemicals of a purity acceptable for the analysis. For details, see ISO 6353-1, ISO 6353-2 and ISO 6353-3. 6.1.3 Water Whe
36、never water is specified without other qualifiers in the test procedures, only distilled water or water of equivalent purity shall be used. ISO 7760:2001(E) 4 ISO 2001 All rights reserved 6.1.4 Strength of solutions 6.1.4.1 Acids and ammonium hydroxide are full strength unless otherwise specified. 6
37、.1.4.2 When a standardized solution is required, its amount-of-substance concentration is expressed in moles per litre. The number of significant figures to which the molarity 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 st
38、andardized 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 is to be diluted, its dilution is indicated by x + y, meaning that x volumes of reagent, or concentrated solution, are to be diluted
39、with y volumes of water (6.1.3). 6.2 Reagents 6.2.1 Sodium hydroxide solution, c(NaOH) 1 mol/l. Dissolve 20,0 g of sodium hydroxide (DANGER: C ) in 400 ml of water. Cool, then transfer to a 500 ml one-mark volumetric flask and dilute to the mark with water. 6.2.2 Sodium hydroxide solution, c(NaOH) 0
40、,25 mol/l. Dilute 50 ml of the 1 mol/l sodium hydroxide (6.2.1) to 200 ml in a 200 ml one-mark volumetric flask. 6.2.3 Citric acid buffer solution Dissolve 53 g of citric acid monohydrate (C 6 H 8 O 7 H 2 O) in about 70 ml of 0,25 mol/l sodium hydroxide (6.2.2). Transfer to a 100 ml one-mark volumet
41、ric flask and dilute to the mark with 0,25 mol/l sodium hydroxide. 6.2.4 Water/methanol mixture (DANGER: S ). Mix 60 ml of water with 90 ml of methanol (DANGER: S ) and cool. 6.2.5 1-Ethylquinaldinium iodide solution, 2 g/l. Dissolve 0,2 g of 1-ethylquinaldinium iodide in 100 ml of the water/methano
42、l mixture (6.2.4) ( S ). Store in a dark glass bottle and discard after 24 h. 6.2.6 1-Pentanol, CH 3 CH 2 CH 2 CH 2 CH 2 OH (DANGER: F ). 6.2.7 Hydrochloric acid solution, HCl 1 + 4 (DANGER: C ). Dilute 40 ml of concentrated hydrochloric acid (DANGER: B C ) to 200 ml. 6.2.8 Hydrochloric acid solutio
43、n, c(HCl) 0,01 mol/l. Add 1,65 ml of concentrated hydrochloric acid ( B C ) to 2 litres of water and mix. 6.2.9 Hydroquinone stock solution, C 6 H 4 (OH) 2(1 ml contains 100 g of hydroquinone). Dissolve 100 mg 1 mg of hydroquinone (DANGER: S ) in about 800 ml of 0,01 mol/l hydrochloric acid (6.2.8).
44、 Transfer to a 1 litre one-mark volumetric flask and dilute to the mark with 0,01 mol/l hydrochloric acid. Store in a dark glass bottle. Prepare a fresh solution each day. ISO 7760:2001(E) ISO 2001 All rights reserved 56.2.10 Hydroquinone standard solution (1 ml contains 5 g of hydroquinone). Pipett
45、e 10 ml of the hydroquinone stock solution (6.2.9) into a 200 ml one-mark volumetric flask and dilute to the mark with 0,01 mol/l hydrochloric acid (6.2.8). Store in a dark glass bottle. Prepare a fresh solution each day. 6.2.11 pH indicator paper, with a pH range of 4 to 5. 7 Apparatus 7.1 General
46、All glassware subject to heating shall be of heat-resistant borosilicate glass 1) .All glassware should be cleaned with hot 1 mol/l hydrochloric acid ( C ) and rinsed thoroughly before use. Pipettes and other volumetric glassware shall meet the requirements specified in ISO 10349-1. 7.2 Spectrophoto
47、meter, for measurements at a wavelength of 675 nm and fitted with two matched silica cells of 1 cm optical path length. 7.3 Micro-pipette, of capacity 0,1 ml. 7.4 Separatory funnels, of capacity 125 ml. 7.5 One-mark volumetric flasks, of capacity 25 ml, 100 ml, 200 ml, 500 ml and 1 litre, conforming
48、 to Class A of ISO 1042 where applicable. 7.6 Pipettes, of capacity 10 ml and 50 ml, conforming to Class A of ISO 648, and 0 ml to 20 ml graduated pipettes. 8 Sampling and sample preparation Hydroquinone S readily undergoes aerial oxidation. In the presence of sulfite or bisulfite (which are common
49、photographic processing effluents), the initial oxidation products are sulfonates which will not respond to this test method. The sample container should therefore be filled to the top to minimize dead air space and should be refrigerated if the analysis cannot be run immediately. Filtration of the sample may be necessary. It is necessary that the analysis be done on a representative sample. The sampling of a process effluent o
