|Values are valid only on day of printing.|
Sodium is performed by flame emission spectrometry/indirect ion-selective electrode (ISE).
Aldosterone is performed by liquid chromatography-tandem mass spectrometry (LC-MS/MS).
Samples are spiked with deuterated internal standard and are hydrolyzed overnight with acid. Samples are then neutralized and extracted by solid phase extraction (SPE). The extracts are dried, reconstituted, and analyzed by LC-MS/MS.(Taylor RL, Singh RJ: Validation of liquid chromatography-tandem mass spectrometry method for analysis of urinary conjugated metanephrine and normetanephrine for screening of pheochromocytoma. Clin Chem 2002 Mar; 48:533-539)
Aldosterone: Monday, Thursday; 3 p.m.
Sodium: Monday through Sunday; Continuously