1、DRAFT FOR DEVELOPMENT Lead and lead alloys Analysis by flame atomic absorption spectrometry (FAAS) or inductively coupled plasma emissions spectrometry (ICP-ES), after separation by Co-precipitation ICs 77.120.60 DD ENV 141 3 8:200 1 Wk - measurement of the absorption of the resonance line energy of
2、 the spectrum from the element at the relevant wavelength (absorbance) ; - comparison with that of calibration solutions of the same element. 3.2.2 Inductively coupled plasma emission spectrometry (ICP-ES) The anaiyte concentration in the test solution is obtained by : - nebulization of the test sol
3、ution into the plasma of an inductively coupled plasma optical emission spectrometer ; - measurement of the intensity of the emission signal from the spectrum of the element to be determined at the relevant wavelength ; - comparison with that of calibration solutions of the same element. 4 Apparatus
4、 4.1 General Use ordinary apparatus as available in a chemical laboratory. All glassware to be used shall be cleaned with diluted hydrochloric acid (5.3.2) and thoroughly rinsed with water. 4.2 Volumetric glassware 4.2.1 1042 class A. One-mark volumetric flasks of capacities 25 ml, 100 ml, 500 ml an
5、d 1 O00 ml in accordance with EN IS0 4.2.2 class A. One-mark pipettes of capacities 5 ml, 10 ml, 15 ml, 20 ml, 25 ml and 50 ml in accordance with IS0 648 4.3 Filtration system Vacuum filtration system with a filter membrane of PTFE, or other material inert to nitric acid, of about 5 pm porosity (fil
6、tering diameter 20 mm to 50 mm). 4.4 Instruments 4.4.1 Flame atomic absorption spectrometer Flame atomic absorption spectrometer (FAAS) equipped with laminar flow burners suitable for acetylene-air, hydrogen-air or acetylene-nitrous oxide flames, and with radiation sources such as hollow cathode lam
7、ps (HCL) or electrode-less discharge lamps (EDL) as appropriate to the element to be determined. The instrument shall be used in accordance with the manufacturers instructions and the performance checked (see also ISO/DIS 13204-2 and ISO/DIS 13204-3). DANGER exhausted externally. To avoid any risk t
8、o personnel due to emission of acid and lead fumes, the off-gas shall be 6 ENV 14138:2001 (E) 4.4.2 Inductively coupled plasma emission spectrometer Inductively coupled plasma emission spectrometer (ICP-ES), either a simultaneous instrument with the relevant wavelengths installed or a sequential ins
9、trument where a monochromator system allows the selection of wavelengths (see also ISO/DIS 12235-1). The instrument shall be used in accordance with the manufacturers instructions and the performances checked (see also ISO/DIS 12235-2). DANGER exhausted externally. To avoid any risk to personnel due
10、 to emission of acid and lead fumes, the off-gas shall be 5 Reagents 5.1 General For all stages of analysis, unless otherwise stated, use only reagents of recognised analytical grade, preferably with an actual analysis, suitable for trace analysis and only water of at least grade 2, as specified in
11、EN IS0 3696. Prepare all solutions using the same container of each reagent. 5.2 Nitric acid (“0,) 5.2.1 Concentrated nitric acid Nitric acid of high purity, which fio = 1,41 g/mI. 5.2.2 Nitric acid 1:l (VW) Add to one volume of water, in a suitable container, the same volume of concentrated nitric
12、acid (5.2.1) and mix thoroughly. 5.2.3 Nitric acid 1:2 (VW) Add 200 ml concentrated nitric acid (5.2.1) to 400 ml water in a 1 O00 ml beaker and mix thoroughly. 5.3 Hydrochloric acid (HCI) 5.3.1 Concentrated hydrochloric acid Hydrochloric acid of high purity, which p20 = 1 ,I 8 g/ml. 5.3.2 Hydrochlo
13、ric acid 1 :I (VW) Add 400 ml of concentrated hydrochloric acid (5.3.1) to 400 ml water in a 1 O00 ml flask. This acid is used to clean all glassware which should be soaked for at least 1 h prior to use, then rinsed thoroughly with water. 5.4 Ammonia solution Ammonia solution of high purity which p2
14、0 = 0,88 g/ml. 5.5 Pure lead For the determination of the recovery rate of the analyte (see 7.2), very pure lead (99,9999 % m/m) should be used. However, lead of lower purity may be used provided that the anaiyte is not present in an amount that could be significant to the determination required. 7
15、ENV 14138:2001 (E) 5.6 Manganese nitrate solution Dissolve (7,OO f 0,Ol) g of hydrated manganese nitrate (Mn(N03),4H20) in water, transfer to a 100 ml volumetric flask, make up to the mark with water and mix thoroughly. 5.7 Potassium permanganate solution Weigh (3,20 f 0,Ol) g of potassium permangan
16、ate (KMn04) into a 600 ml beaker, add 400 ml water and swirl until dissolved. Transfer into a 1 O00 ml volumetric flask, make up to the mark with water and mix thoroughly. 5.8 Standard solutions 5.8.1 Standard solutions (Igll) 5.8.1 .I General Either use commercially available certified standard sol
17、utions or prepare standard solutions as described in 5.8.1.2 to 5.8.1.6. 5.8.1.2 Solution for arsenic Dry approximately 5 g of arsenic oxide (AsO, 99,99 % m/m minimum purity) in an oven at (105 f 2) “C for two hours and allow to cool completely in a desiccator. Weigh (1,320 f 0,001) g of dried arsen
18、ic oxide and transfer into a 250 ml beaker, add 75 ml of nitric acid (5.2.3), cover with a watch glass, and swirl until dissolution is complete. Transfer into a 1 O00 ml volumetric flask (4.2.1) then make up to the mark with water and mix thoroughly. 5.8.1.3 Solution for antimony Dry approximately 5
19、 g of antimony oxide (Sb203, 99,99% m/m minimum purity) in an oven at (105 f 2) “C for two hours and allow to cool completely in a desiccator. Weigh (1,197 f 0,001) g into a 250 ml beaker, add 25 ml of water and 50 ml of concentrated hydrochloric acid (5.3.1), cover with a watch glass and swirl unti
20、l dissolution is complete. Transfer into a 1 O00 ml volumetric flask (4.2.1) then make up to the mark with water and mix thoroughly. 5.8.1.4 Solution for selenium Weigh (1,000 f 0,001) g of selenium (99,99 % m/m minimum purity) into a 250 ml beaker, add 100 ml of nitric acid (5.2.2), cover with a wa
21、tch glass, and heat gently to initiate the reaction of dissolution. Cool if the reaction proceeds too vigorously. Allow to cool, transfer to a 1 O00 ml volumetric flask (4.2.1) then make up to the mark with water and mix thoroughly. 5.8.1.5 Solution for tin Weigh (1,000 f 0,001) g of tin (99,99 % m/
22、m minimum purity) into a 250 ml beaker, add 100 ml of concentrated hydrochloric acid (5.3.1), cover with a watch glass and heat gently until dissolution is complete. Allow to cool, then transfer to a 1 O00 ml volumetric flask (4.2.1) then make up to the mark with water and mix thoroughly. 5.8.1.6 So
23、lution for tellurium Weigh (1,000 f 0,001) g of tellurium (99,99 % m/m minimum purity) into a 250 ml beaker, add 100 ml of nitric acid (5.2.2), cover with a watch glass and swirl until dissolution is complete, transfer into a 1 O00 ml volumetric flask (4.2.1) then make up to the mark with water and
24、mix thoroughly. 5.8.2 Standard solutions (100 mgll) Using a 50 ml pipette (4.2.2) transfer 50 ml of the relevant standard solution (5.8.1) into a 500 ml volumetric flask (4.2.1). Add 50 ml of concentrated hydrochloric acid (5.3.1) then make up to the mark with water and mix thoroughly. 8 ENV 14138:2
25、001 (E) 5.8.3 Standard solutions (1 O mgll) Using a 10 ml pipette (4.2.2), transfer 10 ml of the relevant standard solution (5.8.1) into a 1 O00 ml volumetric flask (4.2.1). Add 50 ml of concentrated hydrochloric acid (5.3.1), then make up to the mark with water and mix thoroughly. Each solution sha
26、ll be prepared on the day of use. 5.8.4 Multi-element solutions (either 10 mgll or 100 mgll) For preparing multi-element solutions, transfer either 10 ml or 100 ml of each relevant standard solution (5.8.1) of the elements required into a 1 O00 ml volumetric flask (4.2.1). Add the appropriate volume
27、 of acid, then make up to the mark with water and mix thoroughly. Each multi-element solution (IO mg/l) shall be prepared on the day of use. 6 Sampling and sample preparation Sampling and preparation of the laboratory sample shall be carried out in accordance with EN 12402. 7 Procedure 7.1 Preparati
28、on of the test solution 7.1 .I Dissolution Weigh (20,OO f 0,Ol) g of the laboratory sample and transfer this test portion into a 250 ml tall-form beaker. Add 60 ml of nitric acid (5.2.3), cover with a watch glass. Heat gently on a hot plate until dissolution of the test portion is complete. Then mak
29、e up to the volume to about 250 ml with water. 7.1.2 Co-precipitation with manganese dioxide 7.1.2.1 using a pH meter. Add ammonia solution (5.4) dropwise to the beaker to adjust the pH of the solution to between 3 and 4 7.1.2.2 Add 2 ml manganese nitrate solution (5.6) and bring to the boil. While
30、still boiling, add 12 ml of potassium permanganate solution (5.7) in three approximately equal portions, boiling gently for 2 min to 3 min after each addition. Cover the beaker with a watch glass and allow to settle for 2 h at 50 OC to 60 OC. Filter the solution through the filter membrane, wash sev
31、eral times with warm water, then discard the filtrate. 7.1.3 Test solution Place a clean receiver back under the filter. With the suction off, add 3 ml of concentrated hydrochloric acid (5.3.1) onto the filter membrane and wait until the dissolution of the precipitate is complete. Apply suction unti
32、l the solution passes through. Repeat this operation using a further 2 ml of concentrated hydrochloric acid (5.3.1). Finally, rinse the filter twice with water, using not more than 10 ml in total. Transfer the filtrate into a 20 ml volumetric flask, make up to the mark with water and mix thoroughly.
33、 7.2 Preparation of the synthetic test solution This solution is used to determine the recovery rate of the anaiyte. Weigh (20,OO f 0,Ol) g of pure lead (5.5) and transfer into a 400 ml beaker. Add the appropriate volume of the relevant standard solution (5.8) to simulate the analyte content to be d
34、etermined in the lead sample. Add 60 ml of nitric acid (5.2.3), cover with a watch glass and heat gently until the dissolution is complete. Then proceed according to 7.1.2 and 7.1.3. 9 ENV 14138:2001 (E) EXAMPLE 1 0,0001 % m/m in the sample. Addition of 2 ml of the standard solution (IO mg/l) (5.8.3
35、) corresponds to a simulated analyte content of Calibration solution number Volume of analyte standard solution (IO mg/l) in the 200 ml flask (mi) Volume of analyte standard solution (100 mg/l) in the 200 ml flask (mi) Analyte concentration in the solution (mg/i) Corresponding analyte content in the
36、 sample (% m/m) EXAMPLE 2 0,0025 % m/m in the sample. Addition of 5 ml of the standard solution (100 mg/l) (5.8.2) corresponds to a simulated analyte content of O 1 2 O 5 10 O O O O O, 25 03 O 0,000025 0,00005 NOTE The recovery rate is normally over 0,9. 7.3 Preparation of the blank test solution 3
37、4 5 20 O O O 5 10 1 23 5 0,0001 0,00025 0,0005 Carry out a blank test in parallel with the preparation of the test solution, following the same procedure (7.1), but omitting the test portion. q? 7.4 Preparation of calibration solutions OP To each of six 200 ml volumetric flasks (4.2.1), labelled O t
38、o 5, add 50 ml of concentrated hydrochloric acid (5.3.1). Then, using one-mark pipettes, add to the flasks respectively the volumes of the relevant standard solution of the analyte (5.8.1 to 5.8.4) given in Table 2 or Table 3. Make up to the mark with water and mix thoroughly. Volume of analyte stan
39、dard solution (100 mg/l) in the Volume of analyte standard solution (lg/l) in the 200 ml 200 ml flask (mi) flask (mi) O 5 10 20 O O O O O 5 Table 3 - Calibration solutions - analyte concentration 2,5 mgll to 50 mgll I Calibration solution number 101 112 I3 14 I Analyte concentration in the solution
40、(mg/i) IO12,51 5 110125 I Corresponding analyte content in the sample (% m/m) I O I 0,00025 I 0,0005 I 0,001 I 0,0025 5 O 10 50 0,005 8 Determination of elements by FAAS 8.1 General Optimise the spectrometer following the manufacturers manual (see also ISO/DIS 13204-2 and ISO/DIS 13204-3), using the
41、 wavelength and the type of flame listed for each anaiyte in Table 4. All the measurements shall be repeated at least twice. The average of these replicate values is the absorbance of the solution. Table 4 -Wavelength and type of flame used for each analyte I I Analyte Wavelength (nm) I Type of flam
42、e I nitrous oxide/acetylene, reducinga I 193,7 I As I I Sb I 206,8 I aidacetylene, oxidising I 10 ENV 14138:2001 (E) Se Sn 196,O nitrous oxide/acetylene, highly reducinga 224,6 nitrous oxide/acetylene, highly reducinga I Te I 214,3 I aidacetylene, oxidising I a precautions. Alternatively, an aidhydr
43、ogen flame may be used. In this case, follow all the special safety 8.2 Calibration and measurement of the test solution 8.2.1 For computerised spectrometers, enter the relevant parameters for the calibration solutions (7.4), the blank test solution (7.3), the test solution (7.1), and the synthetic
44、test solution (7.2). Aspirate the calibration solutions (7.4) in order of increasing concentration, the blank test solution (7.3), the test solution (7.1), and the synthetic test solution (7.2). Read the average analyte concentration of each test solution. 8.2.2 For manual spectrometers, aspirate th
45、e calibration solutions (7.4) in order of increasing concentration, the blank test solution (7.3), the test solution (7.1), and the synthetic test solution (7.2). Plot the calibration graph of absorbance against concentration (mg/i). Convert the absorbance value of each test solution into anaiyte co
46、ncentration using this graph. 8.3 Expression of results 8.3.1 Analyte recovery rate For computerised spectrometers, the analyte content (A % m/m) for the synthetic test solution (7.2) is given directly by the computer, in percentage by mass. For manual spectrometers, the analyte content measured for
47、 the synthetic test solution (7.2) is given by the following formula : V(U - b) A %(m/m) = mx104 where A is the measured anaiyte content, expressed in % (m/m) ; V is the volume of the synthetic test solution in millilitres (mi) ; U is the concentration of anaiyte in the synthetic test solution, in m
48、illigrams per litre (mg/i) ; b is the concentration of anaiyte in the blank test solution, in milligrams per litre (mg/i) ; m is the mass of the synthetic test portion (= 20 9). A Then the analyte recovery rate is : R = - C where C is the simulated anaiyte content expressed in % (m/m). 8.3.2 Analyte
49、 content in the sample a) For computerised spectrometers, the anaiyte content for the test solution given directly by the computer, in percentage by mass, shall be divided by the value of the analyte recovery rate (R) to give the anaiyte content in the sample ; b) for manual spectrometers, the anaiyte content in the laboratory sample is given by the following formula : 11 ENV 14138:2001 (E) V(U - b) A%(m/m) = mx104 XR where A is the anaiyte (endment to be determined) ; V is the volume of the test solution in millilitres (mi) ; U b is the concentration of analyte in the test solution,
