Reinsch test

noun

ˈrīnsh- 

: a test for the presence especially of arsenic, antimony, and mercury in which a strip of clean pure copper foil is heated with the test material in acid solution and then if a black or gray stain appears on the foil, it is heated in a test tube to produce a sublimate deposited in the upper part of the tube in a form characteristic of arsenic, antimony, or mercury if any of these are present