Determination of Cadmium in Seawater by Vapor Generation Atomic Fluorescence Spectrometry After Online Preconcentration with a Novel Alkyl Phosphinic Acid Resin

Abstract

Vapor generation atomic fluorescence spectrometry (VG‐AFS) coupled with online preconcentration on a short column (4.6 mm×50‐mm length) packed with a newly synthesized alkyl phosphinic acid resin (APAR) was developed for the determination of trace Cd in seawater. During the online preconcentration process, Cd in seawater was concentrated on the column while the matrix of seawater was separated flowing out of the column. Cd concentrated on the column was then eluted effectively from the column with 0.1 mol L⁻¹ tartaric acid within 40 s. When the sample volume was 200 mL, an enrichment factor 189 was achieved. The detection limit of this proposed method for Cd is 2.67 ng L⁻¹. The recovery of Cd is 96.6% obtained by spiking the correspondence standard, and the precision (RSD) is 4.34% (n=6). The established APAR/VG‐AFS was applied to the determination of soluble Cd in the seawater around Xiamen Island, China.

Keywords:

• Alkyl phosphinic acid resin
• atomic fluorescence spectrometry
• cadmium
• online preconcentration
• seawater

Acknowledgments

This work was financially supported by the National Natural Science Foundation of China (20475046, 20535020) and the National Basic Research Program of China (2003CD415001, 2003CCA00500). We thank Prof. Benli Huang for continual encouragement and Mr. Dong Yan for assistance with ICP‐MS determination. The loan of the Shimadzu HPLC 2010 and the BRAIC AF‐601A is gratefully acknowledged.

Notes

The authors were invited to contribute this paper to a special issue of the journal entitled “Undergraduate Research and Education in Spectroscopy.” This special issue was organized by Associate Editor David J. Butcher, Professor of Chemistry at Western Carolina University, Cullowhee, North Carolina, USA.