Bismuth (Bi) is the fifth element in Group VA in the periodic table. It has an atomic number of 83, an atomic weight of 208.98, and valences of 3 and 5. The average abundance of Bi in the earth’s crust in 0.08 ppm; in streams it is <0.02 mg/L, and in groundwaters it is <0.1 mg/L. Bismuth occurs in association with lead and silver ores, and occasionally as the native element. 210Bi, 212Bi, and 214Bi are naturally occurring radioisotopes produced in the decay of uranium and thorium. The metal is used in alloys of lead, tin, and cadmium, and in some pharmaceuticals.
In natural water, Bi3+ ion will occur, and complex ions with nitrate and chloride also might form. The iodide and telluride compounds are toxic by ingestion or inhalation.
Perform analyses by the atomic absorption spectrometric method (Section 3111 B) or by the electrothermal atomic absorption method (Section 3113 B). The inductively coupled plasma mass spectrometric method (Section 3125) also may be applied successfully in most cases (with lower detection levels), even though bismuth is not specifically listed as an analyte in the method.