Optimised separation of endogenous urinary components using cyclodextrin-modified micellar electrokinetic capillary...

Area of Science:

• Analytical Chemistry
• Biochemistry

Background:

• Micellar electrokinetic capillary chromatography (MEKC) is crucial for bioanalyte separation.
• Native and modified cyclodextrins (CDs) can improve MEKC performance.
• Human urine analysis presents complex separation challenges.

Purpose of the Study:

• To evaluate native and chemically modified cyclodextrins as buffer additives in MEKC.
• To optimize MEKC conditions for enhanced separation of endogenous urine bioanalytes.
• To assess the efficacy of cyclodextrin-enhanced MEKC in clinical samples.

Main Methods:

• Investigated various cyclodextrins (alpha, beta, gamma-CDs; hydroxypropyl-alpha-CD, hydroxypropyl-beta-CD, methylated beta-CD, sulphated beta-CD, sulphobutyl ether-beta-CD, hydroxypropyl-gamma-CD) as MEKC buffer additives.
• Compared separations with and without cyclodextrin additives.
• Conducted a four-factor, three-level full factorial design to optimize voltage, temperature, pH, and sulphated beta-CD molarity.
• Applied optimized conditions to analyze a human urine pool and clinical samples.

Main Results:

• Sulphated beta-cyclodextrin demonstrated the most significant improvement in peak resolution and separation of urine components.
• Optimized conditions (25 mM sodium tetraborate, pH 9.5, 75 mM sodium dodecyl sulphate, 6.25 mM sulphated beta-CD) resolved 70 peaks within 12 minutes.
• The optimized MEKC method proved effective for analyzing clinical urine samples.

Conclusions:

• Sulphated beta-cyclodextrin is a highly effective additive for improving MEKC separations of human urine bioanalytes.
• The developed optimized MEKC method offers high resolution and efficiency for complex biological samples.
• The method shows promise for routine clinical analysis of urine samples.