Beilstein test

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The Beilstein test is a simple chemical test used in chemistry as a qualitative test for halides. It was developed by Friedrich Konrad Beilstein.[1]

A copper wire is cleaned and heated in a Bunsen burner flame to form a coating of copper(II) oxide. It is then dipped in the sample to be tested and once again heated in a flame. A positive test is indicated by a green flame caused by the formation of a copper halide.

This test is little used nowadays; one reason why it is not popular is that it is possible to generate the highly toxic chloro-dioxins if the test material is a polychloroarene.[2]

An alternative wet test for halide is the sodium fusion test — this test converts organic material to inorganic salts include the sodium halide. Addition of silver nitrate solution causes any halides to precipitate as the respective silver halide.

[edit] References

  1. ^ F. Beilstein (1872). "Ueber den Nachweis von Chlor, Brom und Jod in organischen Substanzen". Ber. Dtsch. chem. Ges. 5 (2): 620-621. doi:10.1002/cber.18720050209. 
  2. ^ Barbara M. Scholz-Böttcher, Müfit Bahadir, Henning Hopf (1992). "The Beilstein Test: An Unintentional Dioxin Source in Analytical and Research Laboratories". Angewandte Chemie International Edition in English 31 (4): 443 - 444. doi:10.1002/anie.199204431.