An Isotope dilution mass spectrometrlc (ID/MS) method for serum urea Is described. The
method utilizes urea-180 as the labeled Internal standard and Involves Isolation of urea from …

A new Isotope dilution mass spectrometrlc method for uric acid Is described. A known weight
of [1, 3-1sN2] urlc acid Is added to a known weight of serum, and the mixture Is allowed to …

Background: A reference measurement procedure is needed to demonstrate the traceability
of results of urea measurements in human serum. We developed a measurement procedure …

The study of urea metabolism In humans necessitates sen-sitive methods, so that very low
Isotopic enrichments of plasma or urinary urea can be measured. A stable derivative of urea …

A method for the measurement of uric acid in human serum by isotope dilution-mass
spectrometry is described. The analytical procedure consists of the following Steps:(1) …

A selected ion-monitoring method, incorporating an internal standard, was developed to
allow the direct and simultaneous measurement of stable isotopelabelled urea and …

A calibration method for isotope dilution mass spectrometry is presented that fully accounts
for non‐linearity of calibration functions, caused by the interference of the analyte on the m/z …

A mass fragmentographic method of high accuracy for determination of serum urea is
described. A fixed amount of [15N 2] urea is added to a fixed amount of serum, then the urea …

A method using a combination of high-performance liquid chromatography and stable-
isotope dilution-mass spectrometry is described for the specific quantitation of uric acid in …

Abstract A GC-MS determination of urea in serum or spent dialysate is described, using 13 C
15 N 2-labelled urea and assaying the area ratio of labelled to natural urea by mass …