Iohexol in serum determined by capillary electrophoresis

Area of Science:

• Analytical Chemistry
• Clinical Chemistry

Background:

• Iohexol is a nonionic compound utilized as a contrast medium in angiography.
• It also serves as a key indicator for assessing glomerular filtration rate.
• Accurate quantification of iohexol in biological samples is crucial for clinical diagnostics.

Purpose of the Study:

• To develop and validate a capillary electrophoresis (CE) method for quantifying iohexol in human serum.
• To compare the efficiency and accuracy of CE with established methods like high-performance liquid chromatography (HPLC).
• To assess the suitability of CE for routine clinical laboratory analysis of small molecules.

Main Methods:

• Serum samples were analyzed using capillary electrophoresis with UV detection at 254 nm.
• Two sample preparation techniques were evaluated: acetonitrile deproteinization and direct dilution with borate buffer.
• 3-isobutyl-1-methylxanthine was employed as the internal standard for quantification.

Main Results:

• Capillary electrophoresis provided comparable results to HPLC, with a high correlation (slope 0.96, intercept 0.005 g/L).
• Acetonitrile deproteinization yielded higher sensitivity compared to direct sample dilution.
• The method demonstrated good precision, with between-run coefficients of variation (CVs) of 4.7-6.7% and within-run CVs of 2.5-3.2%.
• Analytical recoveries ranged from 95-105%.

Conclusions:

• Capillary electrophoresis is a viable, rapid, and simple technique for the quantification of iohexol in serum.
• The CE method offers high accuracy and precision, suitable for clinical applications.
• This study highlights the broad potential of CE for the analysis of various small molecules in biological matrices.