Journal of Applied Physiology, Vol 43, Issue 1 164-166, Copyright © 1977 by American Physiological Society
Preparation of matched reagents for use with the Scholander gas analyzer
R. G. Collins, V. W. Musasche and E. T. Howley
Scholander's method of gas analysis requires that the solutions for CO2
absorber, O2 absorber, and acid-rinse be matched in terms of water vapor
tension throughout the analysis. Any difference in vapor pressure between
either or both of the absorbing solutions and the indicator drop (composed
of acid-rinse) will produce a measurable volume change which cannot be
attributed to the presence of absorbable gases. This paper describes a
practical and quantitative method for preparing reagents whose vapor
pressures are matched. A fixed acid-rinse formulation was used throughout.
A CO2 absorber prepared from 1.35 N KOH and an O2 absorber prepared from
0.76 N KOH were both matched in terms of vapor pressure with Scholander's
acid-rinse solution. Analysis of atmospheric air provided a check on the
accuracy of the technique. The values obtained were O2 20.94%, CO2 0.03%,
and N2 (balance) 79.04%.
