Sample evaporation from pierceable cups: still an important source of analytical error.
BACKGROUND
We illustrate the impact of sample evaporation on analytical results in laboratory practice and highlight preventive measures.


METHODS
Plasma (n=10) was analysed for glucose, Na(+), HCO(3)(-) and calcium on six different sample configurations at 5 time points within 2h.


RESULTS
With time glucose, Na(+) and calcium values increased and HCO(3)(-) values decreased in a clinically significant way.


CONCLUSIONS
Analytical error due to evaporation may be significant, but can be reduced with optimal sample handling. A pierceable cover does not prevent loss of HCO(3)(-).
Schouwers
Sofie
S
Laboratory for Clinical Chemistry and Toxicology, ZNA Stuivenberg, Antwerp, Belgium.
Cuypers
Eric
E
Vervaet
Sabine
S
Uyttenbroeck
Wim
W
Neels
Hugo
H
D001774:Blood Chemical Analysis / Q000592:standards*; D001786:Blood Glucose / Q000032:analysis; D001800:Blood Specimen Collection / Q000295:instrumentation* / Q000379:methods*; D002118:Calcium / Q000097:blood; D002254:Carbonates / Q000097:blood; D006801:Humans; D012964:Sodium / Q000097:blood; D013997:Time Factors
D001786:Blood Glucose; D002254:Carbonates; D012964:Sodium; D002118:Calcium