Selective determination of lithium in biological fluids using flow injection analysis

Area of Science:

• Analytical Chemistry
• Environmental Chemistry

Background:

• Accurate determination of lithium ion is crucial in clinical diagnostics and environmental monitoring.
• Traditional methods for lithium analysis can be time-consuming and require complex sample preparation.

Purpose of the Study:

• To demonstrate automated extraction methods for lithium ion determination using flow injection analysis.
• To evaluate the efficacy of crown ethers and cryptands in selective lithium ion extraction.

Main Methods:

• Ion-pair extraction utilizing cryptand 211 and resazurin for lithium ion determination.
• Chromogenic crown ether-based extraction for lithium ion analysis.
• Flow injection analysis (FIA) for automated sample processing.

Main Results:

• The cryptand 211 method showed a linear range for lithium ion from 70 ppb to 2.1 ppm, tolerating up to 1000 ppm sodium ion.
• The chromogenic crown ether method exhibited a linear range for lithium ion from 0.3 to 2 ppm, with tolerance for 230 ppm sodium ion.
• Both automated methods demonstrated good agreement with established atomic absorption values for lithium in blood serum and urine.

Conclusions:

• Automated flow injection analysis coupled with crown ether or cryptand extraction provides a robust and selective method for lithium ion determination.
• These developed methods are suitable for routine analysis of lithium in biological matrices like blood serum and urine.
• The high tolerance for sodium ions enhances the applicability of these methods in complex sample matrices.