56
using three simultaneous equations and was found to be
5332^ M 'cm ^ at 405 nm.
Concentrations of free 3-aminoacridinium cation,
[BH], and bound monocation, [BHP], were calculated from
absorptiometric data assuming simple additivity of the
absorbances of the two species at the analytical wave
length
A = eBH£[BH] + ?BHptBHP] (2-1)
and considering the mass balance expression
Ct = [BH] + [BHP] (2-2)
where
A = the total absorbance of the solution at a given
wavelength.
e = the molar absorptivity of the free species,
.bn
1.413 x 103 M-1cm_1.
£BHP = mo^ar absorptivity of the bound complex,
8.49£ x 103 M ^cm ^.
H = pathlength of light in the cell.
= the total concentration of free and bound species.
[BH] = the molar concentration of free 3-aminoacridinium
cation.
[BHP] = the molar concentration of bound 3-aminoacridinium-
DNA complex.
Solving equation (2-2) for [BH], substituting into equation
(2-1), and rearranging yields