Automatic On-line Solid-phase Extraction-Electrothermal Atomic Absorption Spectrometry Exploiting Sequential...

Area of Science:

• Analytical Chemistry
• Environmental Science
• Biomedical Analysis

Background:

• Accurate determination of trace heavy metals in biological samples is crucial for health monitoring.
• Existing methods for vanadium, cadmium, and lead analysis in urine can be time-consuming and complex.
• On-line preconcentration techniques can improve sensitivity and efficiency in trace element analysis.

Purpose of the Study:

• To develop a fully automated sequential injection column preconcentration method for on-line determination of trace vanadium, cadmium, and lead in urine.
• To optimize analytical parameters for efficient analyte retention and elution.
• To validate the method's accuracy and precision using certified reference materials and spiked samples.

Main Methods:

• Utilized electrothermal atomic absorption spectrometry (ETAAS) coupled with sequential injection analysis (SIA).
• Employed a handmade minicolumn packed with polyamino-polycarboxylic acid chelating resin (Nobias chelate PA-1) for preconcentration.
• Optimized parameters including sample pH, eluent concentration and volume, and flow rates for on-line analysis.

Main Results:

• Achieved effective on-line retention of vanadium, cadmium, and lead chelates at pH 6.0.
• Determined optimal elution using 1.0 mol L(-1) HNO3 in reverse phase.
• Obtained low detection limits (3.0 ng L(-1) for V, 0.06 ng L(-1) for Cd, 2.0 ng L(-1) for Pb) with good precision (1.9-3.7% RSD).
• Demonstrated high sampling frequency of 27 h(-1) for a 4.5 mL sample volume.

Conclusions:

• The developed automated SIA-ETAAS method provides a sensitive, accurate, and efficient approach for on-line determination of trace V, Cd, and Pb in urine.
• The method is suitable for routine analysis of real urine samples, contributing to toxicological and clinical diagnostics.
• This automated preconcentration technique enhances analytical throughput and reliability for heavy metal monitoring.