Pam. Farias et al., Ultratrace determination of adenine in the presence of copper by adsorptive stripping voltammetry, TALANTA, 55(2), 2001, pp. 281-290
An electrochemical stripping procedure for ultra-trace measurements of aden
ine is described based on the adsorption of the adenine-copper complex on a
static mercury drop electrode. Cyclic voltammetry was used to characterize
the interfacial and redox behavior. Optimum experimental conditions were f
ound when using a 0.005 M NaOH solution containing 0.4 ppm of copper, an ac
cumulation potential of -0.30 V, a scan rate of 100 mV s(-1) and a linear s
can mode. There is a linear response to adenine concentration in the range
of 0.1-1.0 ppb and the detection limit for 6 min accumulation time was of 4
.0 ppt (3.0 x 10(-11) M). Proper conditions for measuring the adenine in pr
esence of guanine, thymine and cytosine were also investigated. The method
was applied for the determination of adenine in a sample of single-stranded
calf thymus DNA. (C) 2001 Elsevier Science B.V. All rights reserved.