BS EN 62321-5-2014 pdf download.Determination of certain substances in electrotechnical products
Part 5: Cadmium, lead and chromium in polymers and electronics and cadmium and lead in metals by AAS, AFS, ICP-OES and ICP-MS.
e) Heating is continued until the carbon is completely oxidized and a clean ash is obtained.
f) Remove the crucible (5.2 g)) and Its contents from the furnace (5.2 m)) and allow to cool to ambient temperature. For AFS, see 7.1.2 h).
g) Add 5 ml of nitric acid (4.2 C) 1)), transfer the resulting solution to a 50 ml volumetric flask (5,2 h) 3)) and fill with water (4.2 a)) to the mark. This is the concentrate sample solution. Dilute the concentrate sample solution with water (4.2 a)) to the appropriate concentration level for each measurement apparatus. If an internal standard (4.2 w)) is to be used, it shall be added before filling. For a final volume of 50 ml. add 500 al of internal standard (4.2 w)) for ICP-OES and for ICP-MS (after a 1:1 000 dilution step) before filling.
h) Transfer the resulting solution to a 100 ml volumetric flask (5.2 h) 3)) and fill with water (4.2 a)) to the mark. Pipet a 2,50 ml portion of the solution to a 100 ml beaker (5.2 e) 2)). Place the beaker on an electric hot plate (5.2 I)). Heat at low temperature until the solution dries completely. Rinse the inside wall of the beaker with some water (4.2 a)), add either 1,0 ml (for determining Cd) or 1,5 ml (for determining Pb) of hydrochloric acid solution (4.2 d) 2)). Heat up slightly to dissolve the salts in the beaker. Cool down the solution to room temperature, and transfer it to a 50 ml volumetric flask (5.2 h) 3)). The solution in the 50 ml flask will be treated in the following steps respectively:
— For determination of Pb, fill with water (4.2 a)) to the mark and mix well.
— For determination of Cd, provided the sample is without impurities such as copper, iron, zinc or nickel etc., add 1,0 ml of cobalt solution (4.2 u)) and 5,0 ml of thiourea solution (4.2 s)) to the volumetric flask, If the sample contains those foreign-metal impurities, then substitute 5,0 ml of thiourea solution (4.2 s) by 10,0 ml of masking agent 2 (4.2 t) 2)). Fill with water (4.2 a)) to the mark and mix well.
If the sample contains significant amounts of halogen compounds (information may be available from previous screening experiments), the following steps shall be carried out:
I) Measure the sample into a crucible (5.2 g)).
j) Add 5 ml to 15 ml of sulfuric acid (4.2 b) 1)) and heat the crucible (5.2 g)) and its contents slowly on a hot plate or sand bath (5.2 I)) until the plastic melts and blackens.
k) After cooling, add 5 ml of nitric acid (4.2 c) 1)) and continue heating until the plastic degrades completely and white fumes are generated.
I) After cooling, the crucible (5.2 g)) is placed in a muffle furnace (5.2 m)) maintained at 550 °C ± 25 °C and the sample is evaporated, dried and ashed until the carbon has been completely incinerated.
m) After ashing, add 5 ml of nitric acid (4.2 c) 1)) and transfer the resulting solution to a 50 ml volumetric flask (5.2 e) 3)) and fill with water (4.2 a)) to the mark. The resulting solution is the concentrate sample solution. Dilute the concentrate sample solution with water (4.2 a)) to the appropriate concentration level for each measurement apparatus. If an internal standard is to be used, It shall be added before filling. For a final volume of 50 ml 500 d of internal standard (4.2 w)) for ICP-OES and ICP-MS (after a 1:1 000 dilution step) shall be added before filling.
7.1.3 Acid digestion method
This method is used to determine Cd arid Cr. It is not suitable for determining Pb. because the sulfuric acid can cause a loss of Pb in the sample due to the formation of PbSO4.
a) Measure the sample into a flask (5.2 e) 1)). Add 5 ml of sulfuric acId (4.2 b.1)) and 1 ml of nitric acid (4.2 c) 1)) and heat the flask until the sample ashes and white fumes are generated. After heating is stopped, nitric acid (4.2 C) 1)) is added in small quantities (approximately 0.5 ml) and heating is continued until white fumes are generated. The heating and decomposition with nitric acid (4.2 c) 1)) are repeated until the decomposed solution turns pale yellow.
b) Allow the sample to cool down for several minutes. Add hydrogen peroxide (4.2 k)) in small quantities, several millilitres at a time, and heat the sample until white fumes are generated. After cooling, transfer the solution to a 100 ml volumetric flask (5.2 e) 3)) and filled with water (4.2 a)) to the mark. The resulting solution is the concentrate sample solution. Dilute the concentrate sample solution with water (4.2 a)) to the appropriate concentration level for each measurement apparatus. If an internal standard Is to be used, it shall be added before filling. For a final volume of 100 ml, add 1 000 j.il of internal standard (4.2 w)) for ICP-OES and ICP-MS (after a 1:1 000 dilution step) before filling.
C) When general digestion is inadequate or when the sample contains significant amounts of Si, Zr. Hf, Ti, Ta, Nb , W (information may be available from previous screening) the following procedures shall be carried out:
— Measure the sample into a flask. Add 5 ml of sulfuric acid and 1 ml of nitric acid and heat the flask until the sample ashes and white fumes are generated. Heating is stopped, add nitric acid (4.2 C) 1)) In small quantities (approximately 0,5 I, and heat until white fumes are generated. The heating and decomposition with nitric acid (4.2 c) 1)) are repeated until the decomposed solution turns pale yellow.
— Allow the sample to cool for several minutes. Hydrogen peroxide is added in small quantities, several millilitres at a time, and heat the sample until white fumes are generated. After cooling, transfer the solution to PTFEIPFA beaker (5.2 h) 1). Add 5 ml of HF (4.2 e)) and heat the vessel until white fumes are generated. Add boric acid (4.2 j)) as desired to permit the complexation of fluoride for protection of the quartz plasma torch (if rio acid-resistant sample introduction system is available). After cooling, transfer the solution to a 100 ml PTFE/PFA volumetric flask (5.2 h) 3)) and fill with water (4.2 a)) to the mark. The resulting solution is the concentrate sample solution. Dilute the concentrate sample solution with water (4.2 a)) to the appropriate concentration level for each measurement apparatus. If an internal standard Is to be used it shall be added before filling. For a final volume of 100 I, add 1 000 p1 of internal standard (4.2 w)) for ICP-OES and ICP-MS (after a 1:1 000 dilution step) before filling.
d) Any sample residues shall be separated by a centrifuge or a filter. The residues shall be checked by appropriate measurements (e.g. XRF, alkali fusion method, other acid digestion methods, etc.) to confirm the absence of target elements. The instruction for XRF is given in IEC 62321-3-1.BS EN 62321-5-2014 pdf download.