Flameless atomic absorption determination of beryllium in the presence of various anions and cations

A method for determining trace amounts of beryllium in the presence of various anions and cations is described. The method involves use of a Perkin-Elmer Model 503 spectrophotometer equipped with an HGA-2100 graphite furnace. The absorption signal from 20 ng/ml of beryllium varies significantly from acid to acid, and both 5 percent (V/V) nitric acid and 5 percent (V/V) sulfuric acid were studied as possible analysis solvents. Absorption signal enhancement and suppression caused by the presence of other chemicals appears similar in either solvent. Concentrations of more than 0.1M hydrochloric and hydrofluoric acid suppress the signal in both solvents. Group II cations, lanthanum, cerium, chromium, molybdenum, tungsten, manganese, aluminum, and silicon, when present in concentrations of 100 μg/ml, enhance the beryllium signal. The addition of 100 μg/ml of lanthanum increases the signal over two fold and masks the signal enhancement caused by the other listed elements; however, hydrochloric and hydrofluoric acids still interfere. The recovery of 20 ng/ml of beryllium in the presence of 100 μg/ml of lanthanum and in the presence of 100 μg/ml each of thirty elements tested is 20 μg/ml with a relative standard deviation of 4 percent and a range of 19 to 22 ng/ml. The presence of lanthanum permits direct detection of less than 1 ng/ml of beryllium in urine