Computerized data treatment for an HPLC-GFAAS system for the identification and quantification of trace element...

Area of Science:

• Analytical Chemistry
• Spectroscopy
• Chromatography

Background:

• Quantifying trace element compounds using liquid chromatography and graphite furnace atomic absorption spectrometry is prone to error due to subjective signal interpretation.
• Existing methods often involve manual judgment for discontinuous spectrometer signals within chromatographic bands, leading to inaccuracies.

Purpose of the Study:

• To develop and validate a computer-controlled system for enhanced quantification of trace element compounds.
• To improve the accuracy and reduce errors in analyzing signals from coupled liquid chromatography and atomic absorption spectrometry.
• To establish precise detection limits for specific selenium species.

Main Methods:

• A high-performance liquid chromatograph was interfaced with a graphite furnace atomic absorption spectrometer using a flow-through cup and autosampler.
• A custom-built interface enabled computer control over aliquot introduction and analysis sequences.
• Spectrometer signals were digitized and processed using selectable algorithms, including data smoothing and various integration methods (Gaussian, spline, trapezium, Simpson).

Main Results:

• The system successfully separated and determined selenite and selenate in aqueous solutions.
• Achieved absolute detection limits of 23 ng Se for selenite and 16 ng Se for selenate (at 3 sigma).
• Demonstrated the system's capability for accurate and reliable trace element quantification.

Conclusions:

• The developed computer-controlled system significantly enhances the accuracy of trace element compound quantification in chromatographic analyses.
• This automated approach minimizes human judgment and reduces errors associated with signal processing.
• The system is adaptable to other spectrometers, offering a versatile tool for trace element analysis.