Clinical Chemistry AACC Online Job Center
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Clinical Chemistry 36: 217-224, 1990;
This Article
Right arrow Full Text (PDF)
Right arrow Submit an electronic Letter to
the Editor about this paper
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Rattenbury, J. M.
Right arrow Articles by Townsend, J. C.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Rattenbury, J. M.
Right arrow Articles by Townsend, J. C.

Clinical Chemistry, Vol 36, 217-224, Copyright © 1990 by American Association for Clinical Chemistry

Establishment of an external quality-assessment scheme for amino acid analyses: results from assays of samples distributed during two years

JM Rattenbury and JC Townsend
Department of Chemical Pathology, Children's Hospital, Sheffield, UK.

Ten different samples of lyophilized plasma and two of liquid urine were distributed during two years to 26 laboratories performing quantitative amino acid analyses in a scheme designed to provide external quality assessment. After each distribution, statistical summaries and performance scores based on delta standard deviations and percentage biases from the all-laboratory trimmed means were returned to participants, who also received annual performance summaries based on their accumulated results. Coefficients of variation calculated from returns across all the samples ranged from 13% for glycine to 65% for methionine. Automated ion-exchange amino acid analyzers with ninhydrin detection appeared to perform better than other methods, although there was no clearly superior method and no model of analyzer clearly outperformed the others. These exercises demonstrate that there is room for improvement in the performance of quantitative amino acid analyses and that individual expertise may be more important in maintaining good performance than the choice of method or analyzer.




HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 1990 by the American Association for Clinical Chemistry.