Norm

IEC 62321-7-2:2017 en;fr

Bepaling van bepaalde stoffen in elektrotechnische producten -Deel 7-2: Zeswaardig chroom - Bepaling van zeswaardig chroom Cr (VI) in polymeren en elektronica door colorimetrie

83,09

Over deze norm

Status Definitief
Aantal pagina's 35
Commissie Milieuaspecten van elektrotechnische apparaten en onderdelen
Gepubliceerd op 01-03-2017
Taal Engels, Frans
IEC 62321-7-2¬†describes procedures to measure hexavalent chromium, Cr(VI), quantitatively in samples of polymers and electronics. This method employs organic solvent to dissolve or swell the sample matrix, followed by an alkaline digestion procedure to extract Cr(VI) from samples. Studies have shown that organic/alkaline solution is more effective than acidic solution in extracting Cr(VI) from soluble and insoluble samples. Minimal reduction of Cr(VI) to Cr(III) or oxidation of Cr(III) to Cr(VI) occurs under alkaline conditions. For soluble polymers consisting of ABS (Acrylonitrile- butadiene-styrene), PC (Polycarbonate) and PVC (poly(vinyl chloride)), the samples are first dissolved in an appropriate organic solvent and Cr(VI) is then extracted by an alkaline extraction solution. For insoluble/unknown polymers, or electronic materials that do not contain antimony (Sb), the samples are digested in a toluene/alkaline solution at 150 °C to 160 °C. Then the organic phase in the extracts are separated and discarded; the inorganic phase is retained for Cr(VI) analysis. The Cr(VI) concentration in the extract is determined by its reaction under acidic conditions with 1,5-diphenylcarbazide. Cr(VI) is reduced to Cr(III) in the reaction with diphenylcarbazide which is oxidized to diphenylcarbazone. The Cr(III) and diphenylcarbazone form a red-violetcoloured complex in the reaction. The complex solution is measured quantitatively by a colorimeter or a spectrophotometer at 540 nm.

Details

ICS-code 31.020
71.040.50
Nederlandse titel Bepaling van bepaalde stoffen in elektrotechnische producten -Deel 7-2: Zeswaardig chroom - Bepaling van zeswaardig chroom Cr (VI) in polymeren en elektronica door colorimetrie
Engelse titel Determination of certain substances in electrotechnical products - Part 7-2: Hexavalent chromium - Determination of hexavalent chromium (Cr(VI)) in polymers and electronics by the colorimetric method
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