Anal. Chem. 2007, 79, 3020
Correction
A typographical error was found in equation (11). This equation should be replaced with
Determination and Modeling of Peptide pKa by Capillary Zone Electrophoresis
pKa ) pH - log
Raphae 1 l Plasson and Herve´ Cottet*
(
[Az-1 ]
[AHz]
xI)/(1+1.6405xI)
10[(z-1) -z ](-0.5085 2
2
) (11)
(Anal. Chem. 2006, 78, 5394-5402).
Equation 7 in the original manuscript should be replaced with
(
µ ) µ0
1+
1 Ka,1 [H+]
+
Ka,1Ka,2
-
[H+]2
)
1 [H ] [H+]2 1+ + Ka,2 Ka,1Ka,2 +
(7)
For a better understanding of the temperature dependence of ∞ ∞ , the pKa,i terms in eqs 25, 28, and 29 should be replaced pKa,i ∞ with pKa,i (0 °C). Thus, eqs 25, 28, and 29 should be replaced by the following
∞ pKa,i ) pKa,i (0 °C) -
This equation can also be written as
µ ) µ0
3.64(n - 1) + βi
+ Θi(T - 273.15) (25)
(
1 1 + 10pH-pKa,1 + 102pH-pKa,1-pKa,2 1 (7bis) pKa,2-pH 1 + 10 + 10pKa,1+pKa,2-2pH
)
Since in the pH zone corresponding to the first (with respect to the second) acidity, the 102pH-pKa,1-pKa,2 term (with respect to 10pKa,1+pKa,2-2pH term) can be neglected, as compared to the 10pH-pKa,1 term (with respect to 10pKa,2-pH term), eq 7bis leads to eq 8, given in the original paper:
(
Ci
)
1 1 µ ) µ0 pH-pKa,1 1 + 10 1 + 10pKa,2-pH
pK∞a,1 (0 °C) ) pKa,1Cterm + 1.00
(28)
pK∞a,2 (0 °C) ) pKa,2Nterm - 1.56
(29)
A typographical error of sign appeared in eq 31 that should be replaced with
pK′a,2 ) pKa,2Nterm - 1.56 - 0.019(T - 273.15) + 2.24 0.5085xI (31) 3.65(n - 1) + 1.1 1 + 1.6405xI
(8)
Equation 9 in the original manuscript should be replaced with AC062219N
pKa ) -log
(
)
( )
aAz-1aH+ aAz-1 ) pH - log aAHz aAHz
3020 Analytical Chemistry, Vol. 79, No. 7, April 1, 2007
(9)
10.1021/ac062219n Published on Web 02/28/2007
10.1021/ac062219n CCC: $37.00
© 2007 American Chemical Society Published on Web 02/28/2007
