Differential pulse adsorptive stripping voltammetric determination of ceftriaxone at a static mercury dropping electrode.

Ceftriaxone is a member of the "third generation" of cephalosporin antibiotics which adsorbs strongly onto a mercury electrode. By using this phenomenon and by accumulating this compound at a static mercury dropping electrode prior to differential pulse voltammetric measurements, very high sensitivities can be readily achieved. The influence of several variables (including accumulation time, modulation amplitude, rest period, scan rate, and drop size) on the adsorptive stripping response has been evaluated. Peak currents were measured with a hanging mercury dropping electrode at -0.78 V versus an Ag/AgCl reference electrode in pH 3.0 Britton-Robinson buffer. The linear calibration range was 3.31 x 10(-11) to 2.17 x 10(-6) M.