Rapid determination of ammonia in a perchloric acid supernate from blood, by use of an ammonia-specific electrode.

A simple,rapidmethod was developed foraccurate determinationof ammonia inwhole blood.Blood proteins were precipitated with perchioric acid (8 g/dl) and the free ammonia liberatedinthe supernateon alkalinization was measured directlywithan ammonia-specific electrode after adjusting the sample temperature to 25 #{176}C. Some variablesaffectingprecision,accuracy, and electrodeperformance were studied.Sensitivity, specificity, and interferences are discussed.The tentativenormal range is28 ± 14 g of ammonia nitrogenper deciliter. The coefficient of variationwas 4.8% in the “normal,”3.6% in the “abnormal” range. Abnormal values were correlated with clinicalstatus.Recoveries averaged 99.3%. Correlationwithan establishedion-exchangemethod forplasma ammonia was 0.994.Totaltime required fora complete assay is15 mm.