Development and validation of a method using supported liquid extraction for aldosterone determination in human...

Area of Science:

• Clinical Chemistry
• Analytical Chemistry
• Mass Spectrometry

Background:

• Accurate aldosterone quantitation is crucial for primary aldosteronism diagnosis.
• Existing methods may lack simplicity or sensitivity.
• A need exists for a robust plasma aldosterone assay in clinical settings.

Purpose of the Study:

• To develop and validate a simple, sensitive method for plasma aldosterone measurement.
• To utilize supported liquid extraction (SLE) with liquid chromatography-tandem mass spectrometry (LC-MS/MS).
• To establish a reliable assay for clinical use.

Main Methods:

• Plasma samples were processed using supported liquid extraction (SLE) with methyl-tert-butyl-ether (MTBE).
• Separation was achieved on a Luna C18 (2) column with methanol-water gradient elution.
• Detection utilized negative electrospray ionization in multiple reaction monitoring (MRM) mode.

Main Results:

• The assay demonstrated linearity up to 3265 pmol/L with a lower limit of quantitation (LOQ) of ~40 pmol/L.
• High precision (<10% CV) and recovery (>97.7%) were observed, with minimal matrix effects (<4%).
• Comparison with another LC-MS/MS method showed excellent correlation (r²=0.974).

Conclusions:

• The developed method is reliable and simple for plasma aldosterone measurement.
• It is suitable for routine clinical laboratory use.
• This assay facilitates accurate screening and diagnosis of primary aldosteronism.