Trace element analysis in biological samples by using XRF spectrometry with secondary radiation

Area of Science:

• Analytical Chemistry
• Biophysics
• Materials Science

Background:

• Accurate in vitro trace element analysis is crucial for biological and medical research.
• Existing X-ray fluorescence (XRF) methods require optimization for sensitivity and accuracy in complex biological matrices.

Purpose of the Study:

• To develop and optimize an X-ray fluorescence (XRF) method for sensitive in vitro trace element analysis in biological samples.
• To identify key parameters for enhancing the sensitivity and reliability of the XRF technique for biological applications.

Main Methods:

• Utilized a monoenergetic radiation source from an X-ray tube with secondary targets.
• Employed 'infinitely thin' specimens and optimized geometrical configurations, including collimators.
• Investigated the impact of high-purity materials for collimators and sample supports.
• Applied preconcentration techniques for biological liquids and tissues to minimize matrix effects.

Main Results:

• Achieved typical sensitivities of 1.6 ng cm-2 for Iron (Fe) and 1.5 ng cm-2 for Rubidium (Rb) within a 1000-second counting time.
• Demonstrated the critical importance of high-purity collimators and thin sample supports for method sensitivity.
• Showcased the effectiveness of a collimator placed between the specimen and detector in reducing unwanted scattering.
• Validated the method's application through successful analysis of blood serum samples.

Conclusions:

• The optimized XRF method provides high sensitivity for in vitro trace element analysis in biological samples.
• Careful selection of materials, geometrical setup, and sample preparation are essential for maximizing XRF performance.
• This technique is suitable for the quantitative analysis of trace elements in complex biological matrices like blood serum.