Microscale modification of a cation exchange column procedure for plasma ammonia

V. G. Oberholzer, K. B. Schwarz, C. H. Smith, D. N. Dietzler, T. L. Hanna

Research output: Contribution to journalArticlepeer-review

8 Scopus citations


A column cation exchange resin procedure for plasma ammonia was modified to require only 100 μl of plasma per determination. Mean analytical recovery of standard from resin (six samples) was 98% (range, 94-100%) as compared to a mean of 63% (range, 58-70) for nine samples when a batch cation exchange procedure was used. Absorbance was proportional to sample concentration up to 800 μmol/liter. Analytical recovery of standard from plasma (six samples) was complete (mean, 103%; range, 90-113). Thirteen aliquots of a specimen of fresh plasma from a single adult individual gave a mean value of 20 μmol/liter (range, 11-26). The mean plasma venous ammonia concentration for 27 adults was 16 μmol/liter (range, 0-39), and for 15 newborns it was 60 (range, 34-102). Values for capillary plasma measured at the same time were higher, and the authors discuss possible explanations for this. Values are given for infants and children from one month to 14 years of age. Effects of storage time and temperature on plasma ammonia concentration are discussed.

Original languageEnglish (US)
Pages (from-to)1976-1981
Number of pages6
JournalUnknown Journal
Issue number12
StatePublished - 1976
Externally publishedYes

ASJC Scopus subject areas

  • Clinical Biochemistry
  • Biochemistry, medical


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