Beilstein test

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The Beilstein test is a simple qualitative chemical test for organic 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. The test does not detect fluorine/fluorides.

This test is no longer frequently used. One reason why it is not widely used 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.

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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.