Adsorptive stripping voltammetric technique for the rapid determination of tobramycin on the hanging mercury electrode

A linear sweep adsorptive stripping voltammetric method (AdS-LSV) for the determination of tobramycin (TOB) has been proposed for the first time. The method is based on the formation of the voltammetrically active iso-butyraldehyde derivative of TOB and the electrochemical behavior of TOB iso-butyraidehyde derivative has been studied. TOB iso-butyraidehyde derivative exhibits a sensitive cathodic peak at -1.40 V (versus SCE) in a medium of B-R buffer (pH 9.8) with a scan rate of 90 mV s(-1) after a preconcentration period of 120 s at - 1.10 V (versus SCE). The linear concentration range of application was 6.87 x 10(-9)-3.44 x 10(-7) mol L-1 of TOB, with a relative standard deviation of 4.4% (for a level of 1.0 x 10(-7) mol L-1) and a detection limit of 3.44 x 10(-9) mol L-1. The method was applied to the direct determination of TOB in injectable formulations and spiked urine and serum samples. (c) 2005 Elsevier B.V. All rights reserved.