automated plasma urea analysis automated plasma urea nitrogen analysis 2022-04-07T15:11:21Z MMO:0000840 This is a method using a device designed to follow a predetermined sequence of individual operations repeatedly and essentially without external influence or control to measure the amount of nitrogen present in plasma, the clear liquid that separates from blood after cells and platelets have been removed. Urea is the chief nitrogenous end product of protein metabolism and is formed in the liver from amino acids and from ammonia compounds and is found in urine, blood, and lymph. measurement_method_ontology slaulede