Validation of routine methods for serum progesterone determination using mass fragmentography

Area of Science:

• Endocrinology
• Analytical Chemistry
• Mass Spectrometry

Background:

• Accurate quantification of serum progesterone is crucial for diagnosing various endocrine disorders.
• Existing radioimmunoassay (RIA) techniques may lack the precision and specificity required for certain clinical applications.

Purpose of the Study:

• To develop and validate a mass fragmentographic reference method for serum progesterone determination.
• To compare the performance of this new method against established radioimmunoassay techniques.

Main Methods:

• A stable isotope-labeled internal standard ([4-14C]progesterone) was used.
• Serum samples were extracted with hexane and purified using thin-layer chromatography.
• Progesterone was derivatized to its dienol heptafluorobutyrate for gas chromatography-mass spectrometry (GC-MS) analysis.
• Quantification was achieved using a multiple ion detector (MID) by monitoring specific mass-to-charge ratios (m/e 510 and 512).

Main Results:

• The mass fragmentographic method demonstrated a relative standard deviation of 3.7% for serum progesterone concentrations between 10-70 nM.
• Comparison with two commercial RIA kits yielded correlation coefficients of 0.93 and 0.76, and regression coefficients of 0.93 and 1.05, respectively.
• The developed method provides a highly specific and reproducible assay for serum progesterone.

Conclusions:

• Mass fragmentography offers a robust and accurate reference method for serum progesterone measurement.
• This technique shows potential for improved diagnostic accuracy compared to certain RIA methods.
• The method's precision and specificity make it valuable for clinical laboratories and research.