Simultaneous quantitation of urine aldosterone and tetrahydroaldosterone in healthy Chinese subjects using a validated LC-MS/MS method.

Aldosterone (ALD) is excreted in urine mainly as glucuronide conjugates of ALD and tetrahydroaldosterone. Measuring these urinary metabolites might be an alternative screening test to plasma ALD for primary aldosteronism. We report a validated LC-MS/MS method to measure both analytes simultaneously.

Chinese normotensive and essential hypertensive reference intervals for plasma aldosterone and renin activity by liquid chromatography-tandem mass spectrometry.

Objectives: The renin-angiotensin-aldosterone system (RAAS) regulates blood pressure. Plasma renin activities (PRA) and plasma aldosterone concentrations (PAC) are biomarkers related to RAAS. Liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based measurements for PRA and PAC have become popular.

Quantitation of plasma angiotensin II in healthy Chinese subjects by a validated liquid chromatography tandem mass spectrometry method.

Quantitation of plasma angiotensin (Ang) II, the active mediator of the renin-angiotensin system, is challenging owing to its low physiological concentration. We report a validated liquid chromatography-mass spectrometry (LCMS) method to overcome this challenge. Ang II was extracted from EDTA plasma by an offline solid-phase extraction procedure with a Waters MAX μElution plate.

Influence of isotopically labeled internal standards on quantification of serum/plasma 17α-hydroxyprogesterone (17OHP) by liquid chromatography mass spectrometry.

Objectives Our recent survey of 44 mass spectrometry laboratories across 17 countries identified variation in internal standard (IS) choice for the measurement of serum/plasma 17α-hydroxyprogesterone (17OHP) by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The choice of IS may contribute to inter-method variations. This study evaluated the effect of two common isotopically labeled IS on the quantification of 17OHP by LC-MS/MS.