Real Sample Analysis by ETA-LEAFS with Background Correction: Application to Gold Determination in River Water

Abstract

Laser-induced fluorescence has been demonstrated to be a very powerful technique for ultratrace analysis in liquid samples. This paper presents results obtained for gold analysis in river water. Single-step excited direct line fluorescence is performed in a commercial graphite furnace tube atomizer. A specially designed dual monochromator setup is used to correct background fluorescence resulting from a high concentration of molecular species in the matrix. Sensitivity is illustrated by detection limits obtained in pure water (4 fg for cobalt and 10 fg for gold), and the background correction efficiency is demonstrated by the analysis of gold in river water at 300 fg level with a 15% precision.