《BS-6068-2.29-1987 ISO-8288-1986.pdf》由会员分享，可在线阅读，更多相关《BS-6068-2.29-1987 ISO-8288-1986.pdf（16页珍藏版）》请在三一文库上搜索。
1、BRITISH STANDARD BS 6068-2.29: 1987 ISO 8288:1986 Water quality Part 2: Physical, chemical and biochemical methods Section 2.29 Determination of cobalt, nickel, copper, zinc, cadmium and lead: flame atomic absorption spectrometric methods ISO title: Water quality Determination of cobalt, nickel, cop
2、per, zinc, cadmium and lead Flame atomic absorption spectrometric methods UDC 556.11 + 614.777 + 628.1/.3 + 663.63:53/54 Licensed Copy: sheffieldun sheffieldun, na, Tue Dec 05 01:29:35 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 6068-2.29:1987 This British Standard, having been prepared under the
3、direction of the Environment and Pollution Standards Committee, was published under the authority of the Board of BSI and comes into effect on 27 February 1987 BSI 06-1999 The following BSI references relate to the work on this standard: Committee reference EPC/44 Draft for comment 85/50076 DC ISBN
4、0 580 15655 9 Amendments issued since publication Amd. No.Date of issueComments Licensed Copy: sheffieldun sheffieldun, na, Tue Dec 05 01:29:35 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 6068-2.29:1987 BSI 06-1999i Contents Page National forewordii 1Scope1 2Field of application1 Section 1. Method
5、 A Direct determination by flame atomic absorption spectrometry 3Principle2 4Reagents2 5Apparatus2 6Sampling and samples2 7Procedure2 8Expression of results3 9Test report3 Section 2. Method B Determination by flame atomic absorption spectrometry after chelation (APDC) and extraction (MIBK) 10Princip
6、le4 11Reagents4 12Apparatus4 13Sampling and samples4 14Procedure4 15Expression of results5 16Test report5 Section 3. Method C Determination by flame atomic absorption spectrometry after chelation (HMA-HMDC) and extraction (DIPK-xylene) 17Principle7 18Reagents7 19Apparatus7 20Sampling and samples7 21
7、Procedure7 22Expression of results8 23Test report9 Annex A Pretreatment of the sample when determining total metals10 Annex B Checking complete extraction (Method C)10 Table 11 Table 21 Table 31 Table 43 Table 53 Table 65 Table 76 Table 89 Licensed Copy: sheffieldun sheffieldun, na, Tue Dec 05 01:29
8、:35 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 6068-2.29:1987 ii BSI 06-1999 National foreword This Section of BS 6068, which has been prepared under the direction of the Environment and Pollution Standards Committee, is identical with ISO 8288-1986 “Water quality Determination of cobalt, nickel,
9、 copper, zinc, cadmium and lead Flame atomic absorption spectrometric methods”. The international standard was prepared by subcommittee 2, Physical, chemical and biochemical methods, of Technical Committee 147, Water quality, of the International Organization for Standardization (ISO) as a result of
10、 discussion in which the UK participated. This British Standard is being published in a series of Parts subdivided into Sections that will generally correspond to particular international standards. Sections are being, or will be, published in Parts 1 to 6, which together with Part 0, are listed bel
11、ow. Part 0: Introduction; Part 1: Glossary; Part 2: Physical, chemical and biochemical methods; Part 3: Radiological methods; Part 4: Microbiological methods; Part 5: Biological methods; Part 6: Sampling. Terminology and conventions. The text of the international standard has been approved as suitab
12、le for publication as a British Standard without deviation. Some terminology and certain conventions are not identical with those used in British Standards; attention is drawn especially to the following. The comma has been used as a decimal marker. In British Standards it is current practice to use
13、 a full point on the baseline as the decimal marker. In British Standards it is current practice to use the symbol “L” for litre (and in its submultiples) rather than “l”, and to use the spelling “sulphur”, etc., instead of “sulfur”, etc. Wherever the words “this International Standard” appear, refe
14、rring to this standard, they should be read as “this Section of this British Standard”. NOTETypographical errors. In 18.6, paragraph 1, line 1, and paragraph 3, line 1, “solutions” should be read as “solution”. In 22.3, paragraph 3, line 1, “neutral” should be read as “natural”. A British Standard d
15、oes not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an in
16、side front cover, pages i and ii, pages 1 to 10 and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Licensed Copy: sheffieldun sheffieldun, na, Tue Dec 05 01:29:35 GMT
17、+00:00 2006, Uncontrolled Copy, (c) BSI BS 6068-2.29:1987 BSI 06-19991 1 Scope This International Standard specifies three methods for the determination of cobalt, nickel, copper, zinc, cadmium and lead in water by flame atomic absorption spectrometry: Section 1: method A, for direct determination b
18、y flame atomic absorption spectrometry; Section 2: method B, for determination by flame atomic absorption spectrometry after chelation (APDC) and extraction (MIBK); Section 3: method C, for determination by flame atomic absorption spectrometry after chelation (HMA-HMDC) and extraction (DIPK-xylene).
19、 2 Field of application 2.1 Method A is particularly applicable when concentrations of elements to be analysed are relatively high and when there are no interferences. When the samples are of a complex or unknown nature or when they contain high concentrations of dissolved solids (brines or brackish
20、 waters) method A is not applicable and either method B or C should be selected. The concentrations of elements which can be determined by method A may vary according to the characteristics of the atomic absorption spectrometric apparatus used but are generally in the ranges indicated in Table 1. Ta
21、ble 1 If the concentrations are greater than the upper limits indicated in the table, the sample may be diluted before analysis. 2.2 Methods B and C are applicable when concentrations of elements to be analysed in the sample (or dilution of the sample) are greater than 0,5 4g/l. 2.2.1 Method B The c
22、oncentrations of the elements which can be determined by method B may vary according to the characteristics of the atomic absorption spectrometer used but are generally in the ranges indicated in Table 2. Table 2 2.2.2 Method C With a ratio of test portion to extraction solution of 20 to 1 by volume
23、 as indicated in 21.2, the concentrations of elements which can be determined by method C vary as indicated in Table 3. Table 3 Lower concentrations may be determined by choosing a higher ratio of test portion to extraction solution. A ratio of 50 to 1 by volume is possible since the organic solvent
24、 mixture is only very slightly soluble in water. With method C, separation of the aqueous and the organic phases is faster. The metal chelates, especially the Cd-chelate, are more stable in the organic solvent mixture. NOTE 1When determining total metals, it is necessary to pretreat the sample befor
25、e analysis (see examples of procedures in Annex A). NOTE 2Methods B and C are not applicable when the chemical oxygen demand (COD) of the samples (or diluted samples) is greater than 500 mg/l. Element to be determined Range of determination (mg/l) Cobalt Nickel Copper Zinc Cadmium Lead 0,1 to 10 0,1
26、 to 10 0,05 to 6 0,05 to 2 0,02 to 2 0,2 to 10 Element to be determined Range of determination (4g/l) Cobalt Nickel Copper Zinc Cadmium Lead 1to 200 1to 200 1to 200 0,5 to50 0,5 to50 5to 200 Element to be determined Range of determination (4g/l) Cobalt Nickel Copper Zinc Cadmium Lead 0,5 to 100 0,5
27、to 100 0,5 to 100 0,2 to50 0,2 to50 2to 200 Licensed Copy: sheffieldun sheffieldun, na, Tue Dec 05 01:29:35 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 6068-2.29:1987 2 BSI 06-1999 Section 1. Method A Direct determination by flame atomic absorption spectrometry 3 Principle Aspiration into the flam
28、e of an atomic absorption spectrometer of a test portion of the acidified filtrate of the sample (or diluted sample). Direct determination of the concentration of each element, either from the specific absorbance of each element using a spectrometer fitted with a continuous background correction sys
29、tem, or, in the absence of such a system, after having carried out a correction for a non-specific absorbance. 4 Reagents All reagents shall be of recognized analytical grade so that their use does not affect the accuracy of the determination. The water used shall be deionized water or distilled wat
30、er containing no detectable concentration of the metals being determined when analysed by a blank test. 4.1 Nitric acid, A = 1,4 g/ml. 4.2 Nitric acid, c(HNO3) 1,5 mol/l. Add 100 ml of nitric acid (4.1) to 600 ml of water and dilute to 1 000 ml. 4.3 Nitric acid, c(HNO3) 0,03 mol/l. Add 1 ml of nitri
31、c acid (4.1) to 400 ml of water and dilute to 500 ml with water. 4.4 Metals, standard solutions corresponding to 1,000 g of metal per litre.1) For each element to be determined, weigh 1,000 g of pure metal and dissolve it in nitric acid (4.1), heating to effect complete dissolution. Allow to cool an
32、d transfer each solution quantitatively to a 1 000 ml one-mark volumetric flask, dilute to the mark with water and mix. For preparing standard solutions, it is also permissible to use metal salts of accurately known composition. Store each of the standard solutions in either polyethylene or borosili
33、cate glass containers. 1 ml of each of these standard solutions contains 1,00 mg of the respective metal. 5 Apparatus Usual laboratory equipment, and Atomic absorption spectrometer, fitted with hollow cathode lamps for the appropriate metals or electrodeless discharge lamps, and with a suitable devi
34、ce for allowing for the correction of the non-specific absorbance and with a nebulizerburner with an acetylene-air flame. Follow the manufacturers instructions for adjusting all instrument parameters. NOTE ON CLEANING OF GLASSWARE All the glassware shall be carefully soaked in nitric acid (4.2) then
35、 rinsed with water. 6 Sampling and samples 6.1 Polyethylene or borosilicate glass containers which have been previously cleaned with nitric acid (4.2) then rinsed with water, shall be used for sampling. 6.2 If total metals are to be determined, samples shall be treated by the addition of nitric acid
36、 (4.1) immediately after collection in order to obtain a pH between 1 and 2 (usually 2 ml of acid per litre of sample is sufficient). Note the amount of acid added and use the same volume in the preparation of the blank (7.2). If only dissolved metals are to be determined, filter the sample as soon
37、as possible after collection through a membrane filter of nominal pore diameter 0,45 4m and acidify the filtrate immediately with nitric acid (4.1) in order to obtain a pH between 1 and 2. Before use, filters shall be thoroughly washed with nitric acid (4.2) and rinsed with water. 7 Procedure 7.1 Te
38、st portion Into a 100 ml one-mark volumetric flask, place a test portion of the acidified sample (6.2) such that it contains 0,2 to 1 mg of metal (see Table 1 for the upper limits corresponding to each element). Make up to the mark with water. 7.2 Blank test Carry out a blank test in parallel with t
39、he determination, by the same procedure, using the same quantities of all the reagents as in the sampling and determination, but replacing the test portion by water. 7.3 Preparation of the sets of calibration solutions Before each batch of determinations, prepare from each of the standard solutions
40、(4.4) at least four calibration solutions covering, for each element, the range of the concentrations to be determined. Prepare these calibration solutions by diluting standard solutions (4.4) with nitric acid (4.3). 1) Standard solutions are commercially available. Licensed Copy: sheffieldun sheffi
41、eldun, na, Tue Dec 05 01:29:35 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 6068-2.29:1987 BSI 06-19993 7.4 Calibration and determination Proceed as follows for each metal being determined. Before carrying out the spectrometric measurements, set up the spectrometer according to the manufacturers in
42、structions by aspirating a calibration solution (7.3) of the particular metal being determined and using the information in Table 4. Optimize the aspiration and flame conditions (aspiration rate, nature of the flame, position of the optical beam in the flame). Adjust the response of the instrument t
43、o zero absorbance with water. Table 4 For each metal being determined, aspirate the set of calibration solutions (7.3) and, as zero member, the blank solution (7.2). Plot a graph having the metal contents, in milligrams per litre, of the calibration solutions as abscissae and the corresponding value
44、s of absorbance as ordinates. It is advisable that the calibration graph be checked, for example by measuring the absorbance of a calibration solution every 5 samples. Aspirate the test portion (7.1) into the flame of the burner. Measure the absorbance of the metal being determined and after each me
45、asurement aspirate the nitric acid (4.3) in order to rinse the nebulizer system. NOTE ON CORRECTION FOR NON-SPECIFIC ABSORPTION If the spectrometer used is not fitted with a background correction system which supplies automatically a signal corresponding to the specific absorbance A of the metal to
46、be determined, it is necessary to measure the non-specific absorbance A0. To do this, proceed as follows. Choose a spectral line in the proximity of that of the metal to be determined in order to ensure that the difference between the wavelengths of the two spectral lines does not exceed 1 nm. Use a
47、 spectral line of the gas contained in a hollow cathode lamp (argon or neon), or a spectral line emitted by a zirconium or deuterium hollow cathode lamp (see Table 5). Measure the absorbance A0 corresponding to this spectral line by reaspirating the test portion. Calculate the specific absorbance A
48、= A1 A0 where A1 is the total absorbance at the wavelength of analysis. The flame conditions and the energy assigned to the lamps shall remain unchanged throughout the measurements of the absorbances A1 and A0. Table 5 7.5 Check test Carry out check tests in order to reveal any matrix effect. To do
49、this, use the method of standard additions. If a matrix effect is found to be present, the method is not applicable: recommence the determination using either method B or method C or use the results obtained by the method of standard additions. 8 Expression of results By reference to the calibration graph, determine, for each metal, the concentrations corresponding to the absorbances of the test portion (7.4) and of the blank (7.2). For each metal being determined, the concentration, expressed in milligrams per litre, of the sample is