Automated isotope dilution liquid chromatography-tandem mass spectrometry with on-line dilution and solid phase extraction for the measurement of cortisol in human serum sample

作者：Kawaguchi Migaku^*; Eyama Sakae; Takatsu Akiko

来源：Journal of Pharmaceutical and Biomedical Analysis, 2014, 96: 220-223.

DOI：10.1016/j.jpba.2014.03.015

• Isotope dilution mass spectrometry
• Cortisol
• Liquid chromatography-tandem mass spectrometry (LC-MS/MS)
• On-line dilution
• On-line solid phase extraction (SPE)

A candidate reference measurement procedure involving automated isotope dilution coupled with liquid chromatography-tandem mass spectrometry (ID-LC-MS/MS) with on-line dilution and solid phase extraction (SPE) has been developed and critically evaluated. We constructed the LC-MS/MS with on-line dilution and SPE system. An isotopically labelled internal standard, cortisol-d(4), was added to serum sample. After equilibration, the methanol was added to the sample, and deproteination was performed. Then, the sample was applied to the LC-MS/MS system. The limit of detection (LOD) and limit of quantification (LOQ) were 0.2 and 1 ngg(-1), respectively. Excellent precision was obtained with within-day variation (RSD) of 1.9% for ID-LC-MS/MS analysis (n = 6). This method, which demonstrates simple, easy, good accuracy, high precision, and is free from interferences from structural analogues, qualifies as a reference measurement procedure.

• 出版日期2014-8-5