Ammonia is a product of amino acid metabolism and the major source of circulating
ammonia is the gastrointestinal tract. 2 It is neurotoxic, possibly due to its effect on the …

Urea is an essential molecule usually detected using spectroscopy, particularly ultraviolet
and visible spectroscopy (UV-vis). However, its detection represents a not always fully …

The history of clinical and biological sciences is to a great extent that of the development of
different methodologies. Sooner or later, most biological problems lead to experimental …

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

Creatinine is isolated from lyophilized serum or urine with added [15N2] creatinine by high-
performance liquid chromatography. It is converted to the di-trifluoroacetate of the (2 …

This paper presents the development of a simple, low cost, the new type of urea sensor, and
suitable for water quality monitoring. Here, urease is immobilized on the electrodes using …

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 …

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 …

Exhaled breath condensate (EBC) provides a relatively easy, non-invasive method for
measuring biomarkers of inflammation and oxidative stress in the airways. However, the …

Serum from patients was pooled, filtered, dispensed, and frozen. This pooled specimen was
used for accuracy control in 64 participating laboratories in Sweden. Mean values (" state-of …