JULY. 1950
0
A SPOT TEST FOR BISMUTH ALFRED 1. MOSES Iowa State College, Ames,Iowa
.' states that bismuth forms crystalline yellow phenolates from acid solutions. When an alkylated phenol, 6-tert-butyl-3-methylphenol is used as a reagent, in which several alkyl groups are substituted on the benzene ring, a very dark precipitate is obtained. The test is performed on spot paper, which has been treated with the reagent and allowed to dry. Application of the unknown bismuth-containing solution resnlt,s in a brown spot on drying. Tests were performed in the presence of a number of the metals in the first and second qualitative groups. As silver yields a black spot, its presence interferes with the test. Acid solutions containing 0.1 per cent of the metals in question as well as 0.2 per cent, 0.02 per cent, 0.01 per cent, and 0.005 per cent bismuth vere prepared and the limit of identification of bismuth in the presence of these metals established. See tabulated resultas: FEIGI,,FRITZ, "Chemistry of Specific, Selective, and Semit i n Reactions," Academy Press, New York, 1949, p. 377.
Ri
As
Sb
Cu
Cd
Ho
Pb
Sn
Result
It was noticed that where heating was resorted to in an effort to accelerate the reaction, a green color was first produced, which changed to brown on standing in air. The test is suitable for the confirmation of bismuth down to approximately 2.5 p, while in solutions containing other ions of the copper-arsenic groups the limit is somewhat higher. The author wishes to thank Dr. F. E. Brown for his encouragement and the Koppers Company of Pittsburgh for their contribution of the reagent.
