Chemical Vapor Generation: Atomic Absorption by Ag, Au, Cu, and Zn Following Reduction of Aquo Ions with Sodium Tetrahydroborate(III)

Abstract

Volatile species of Ag, Au, Cu, Zn, Cd, and As were generated at room temperature by the addition of sodium tetrahydroborate(III) to an acidified solution of the analytes. The vapor-phase species were rapidly transported to a heated quartz tube atomizer (QTA) for detection by atomic absorption spectrometry. A univariate approach was used to achieve optimized conditions and derive analytical figures of merit. The analytes are released from solution as molecular species (likely as metal hydrides) and are (partially) atomized in the QTA under nonoptimized conditions. Detection limits range from 1.8 (Zn) to 420 ng (Au). The efficiency of the generation process is estimated to be 92 ± 4% for Au. Loss of analyte during transport to the QTA was minimized through use of the minimum length of narrow-bore Teflon transfer line possible.