Development and Application of a Hydride Generation Laser Induced Fluorescence Method for Measurements of Bismuth

Abstract

A hydride generation laser induced fluorescence (HG LIF) approach has been investigated for trace level measurements of bismuth. The technique uses a tunable dye laser operating at 306.7 nm as the excitation source and bismuth fluorescence is measured at 472 nm. The optimized HCl and NaBH₄ concentrations for bismuth measurements were 1.2 M and 2.0%, respectively. The current technique has a limit of detection of 0.03 ppb and 0.01 ppb for blank measurements performed with the laser tuned on and off the bismuth excitation wavelength, respectively. Measurements of bismuth in different sample matrices have demonstrated the effectiveness of thiourea and ascorbic acid as masking agents for measuring samples containing interfering ions. Measurements of bismuth have been performed in reference materials, a bismuth-containing medication, and tea leaves. The results demonstrate that the HG LIF approach has feasibility for measuring bismuth in various samples at environmentally relevant concentrations.

Keywords:

• Bismuth
• HG LIF
• Hydride generation
• Laser induced fluorescence
• Tea leaves

Acknowledgments

The authors gratefully acknowledge Advanced Monitoring Inc. for the loan of the instrumentation used in these studies and for research support from the Department of Chemistry and the School of Graduate Studies at Youngstown State University. Muhsin Ezer also acknowledges support from the Council of Higher Education of Turkey for his visit to Youngstown State University.

Notes

^a Corresponds to blank measurements performed with laser tuned on/off Bi excitation wavelength.