5/1/2023 0 Comments Hexavalent chromium exposure![]() Neither test can be used to determine unambiguously whether the concentration in a homogeneous material is over 0.1%, but they can be used to detect the presence of chromium(VI). A screening boiling test where the piece is extracted for some time in de-ionised water at near-boiling point temperatures.A spot test where chromium(VI) is dissolved in a drop of test liquid directly on the piece or in a white weighing boat.Two methods are based on the corresponding methods described in IEC 62321. In order to test for chromium(VI) in the passivation layer it is necessary to dissolve chromium(VI) in the test liquid and to ensure that chromium(VI) is not oxidised to chromium(III) before the colour reaction occurs. The screening method can be used to determine chromium(VI) in passivation layers on metal pieces.Īs mentioned above, the method is based on a colour reaction in a test liquid. ![]() The test conditions most suited for a simple and quick screening method to be used without access to a fully equipped analysis laboratory have also been examined.īased on the development work, the following section describes a test procedure and provides instructions as to the interpretation of test results. The experiments, which are described in further detail in Annex 2, examine the sensitivity of the method in relation to different test materials. 4.1 Development workĪ number of experiments have been conducted in order to examine the possibilities and limitations of a screening test method based on visual colorimetric determination. Spectroquant® test kits are available from VWR - Bie & Berntsen A/S, among others. An example is the Chromate Cell Test from Spectroquant®, which follows the US standards method 3500-Cr D. The colorimetric method is also used to determine chromium(VI) in other media, and commercial test kits are available for drinking water and waste water analyses, among others, that are capable of testing for chromium(VI) in liquid volumes of 5-10 ml in special test tubes. 540 nm.įor a precise determination of the intensity of the red colour, and thus the chromium content in the test liquid, a spectrophotometer is required, but the red colour can also be observed with the naked eye, and the screening method developed is based on that principle. It is based on the reduction of chromium(VI) to chromium(III) in a reaction with 1.5 diphenylcarbazide oxidised to 1.5 diphenylcarbazone.ġ.5 diphenylcarbazone yields a characteristic reddish purple colour with an absorption maximum of approx. ![]() The method is based on a colorimetric determination of the chromium(VI) content in a test liquid (colorimetry = determination by colour reaction). This standard provides a method to determine levels of chromium(VI) (for further information about the method, see Chapter 5). The International Electrotechnical Commission published an international standard in January 2009, including procedures for the determination of levels of regulated substances in electrotechnical products, IEC 62321. In order to determine whether a piece contains chromium in a particular oxidation state (in this case hexavalent chromium, in the following referred to as chromium(VI)), it is necessary to use methods based on redox reactions that are specifically sensitive to the oxidation state in which chromium is present. ![]() | Front page | | Contents | | Previous | | Next |ĭevelopment and use of screening methods to determine chromium (VI) and brominated flame retardants in electrical and electronic equipment 4 Screening method to determine hexavalent chromium in surfaces 1292 2009 – Development and use of screening methods to determine chromium (VI) and brominated flame retardants in electrical and electronic equipment 4 Screening method to determine hexavalent chromium in surfaces – Environmental Project No. ![]()
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