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EVS-EN 62321-7-2:2017

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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Kehtiv alates 05.07.2017
Alusdokumendid
IEC 62321-7-2:2017; EN 62321-7-2:2017
Direktiivid või määrused
puuduvad
Standardi ajalugu
Staatus
Kuupäev
Tüüp
Nimetus
05.07.2017
Põhitekst
04.06.2009
Põhitekst
This part of IEC 62321 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.
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EVS-EN 62321-7-1:2015

Determination of certain substances in electrotechnical products - Part 7-1: Determination of the presence of hexavalent chromium (Cr(VI)) in colorless and colored corrosion-protected coatings on metals by the colorimetric method
Uusim versioon Kehtiv alates 05.01.2016
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EVS-EN 62321-2:2014

Determination of certain substances in electrotechnical products - Part 2: Disassembly, disjointment and mechanical sample preparation
Uusim versioon Kehtiv alates 05.06.2014
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EVS-EN 62321-3-1:2014

Determination of certain substances in electrotechnical products - Part 3-1: Screening - Lead, mercury, cadmium, total chromium and total bromine by X-ray fluorescence spectrometry
Uusim versioon Kehtiv alates 05.06.2014
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EVS-EN 62321-3-2:2014

Determination of certain substances in electrotechnical products - Part 3-2: Screening - Total bromine in polymers and electronics by Combustion - Ion Chromatography
Uusim versioon Kehtiv alates 05.06.2014