Analytical Sciences

Abstract − Analytical Sciences, 22(1), 51 (2006).

Minicolumn Field Sampling-Preconcentration of Trace Zinc from Seawater and Its Laboratory Detection by Flow Injection Flame Atomic Absorption Spectrometry
Department of Analytical Chemistry, Nutrition and Bromatology, Faculty of Chemistry, University of Santiago de Compostela, 15782-Santiago de Compostela, Spain
A simple field sampling-preconcentration method for zinc determination in seawater is described. Seawater was collected in situ by pumping it through a minicolumn packed with a chelating resin (Chelite P) connected to a field flow preconcentration system (FFPS). These packed minicolumns retain the dissolved zinc, and once are loaded with the analyte, they are returned to the laboratory where they are sequentially inserted into a flow injection system for on-line zinc elution with diluted hydrochloric acid and flame atomic absorption spectrometric detection. A factorial design has been used to optimize the FFPS and the flow injection elution process. The proposed method has a linear calibration range from 0.07 to at least 9.4 µg L-1 of zinc, with a detection limit of 0.02 µg L-1 and a throughput of 26 samples h-1. Validation was carried out against certified reference water samples. This procedure has been successfully applied to the determination of Zn in seawater samples from Galicia (Spain).