Frans_M_Everaerts_Isotachophoresis_378342.pdf

280 QUANTITATIVE ASPECTS
10.4.2. Calibration constant
In Tables 10.3-10.5, the results are shown of analyses with nitrate, chlorate and
acetate. In addition to the pure components, mixtures of them were also injected. The
concentration was chosen such that a 0.5-pl volume could be injected each time. The
current was stabilized at 70 MA. Glutamic acid was applied as the terminator, at a
concentration of 0.01 N. The average results of two experiments are given.
The actual concentrations of the ionic species in the zones, in the steady state,
moving behind the leading electrolyte were again calculated with the computer program
given in Chapter 4. As expected, a linear relationship between zone length and amount of
component injected was found at low concentrations.
For the calculation of the calibration constant, an average of the values listed in
TABLE 10.3
ZONE LENGTHS FOUND EXPERIMENTALLY AT A CONCENTRATION OF 0.0125NIN THE
SYSTEM HISTIDINE/HISTIDINE HYDROCHLORIDE WITH A CONDUCTIVITY DETECTOR
Ion I. * K,,, .1 o4
NO,- 13.5 - - 14.1 - 13.8 14.1 0.448
Cl0,- - 13.5 - 13.8 14.1 - 13.8 0.461
CH, COO- - - 15.6 - 15.9 16.2 16.2 0.462
TABLE 10.4
ZONE LENGTHS FOUND EXPERIMENTALLY AT A CONCENTRATION OF 0.025NIN THE
SYSTEM HISTIDINE/HISTIDINE HYDROCHLORIDE WITH A CONDUCTIVITY DETECTOR
Ion L* K,d’ lo4
NO,- 21.9 - - 28.2 - 21.9 28.2 0.448
(30,- - 28.5 - 28.2 21.9 - 28.2 0.451
CH, COO- - - 32.1 - 31.8 31.8 31.8 0.459
TABLE 10.5
ZONE LENGTHS FOUND EXPERIMENTALLY AT A CONCENTRATION OF 0.05 N IN THE
SYSTEM HISTIDINE/HISTIDINE HYDROCHLORIDE WITH A CONDUCTIVITY DETECTOR
Ion L* K,~, 104
NO,- 51.3 - - 56.1 - 56.1 51.3 0.443
Cl0; - 56.1 - 51.3 51.6 - 51.9 0.452
CH,COO- - - 63.6 - 62.1 62.1 64.8 0.460