Simultaneous determination for toxic ractopamine and salbutamol in pork sample using hybrid carbon nanotubes

Hybrid carbon nanotubes (CNTs) and Nafion (NF) composites have been successfully prepared on an electrode surface with background current ratio as 3:4:16 for single-walled CNTs (SWCNT), multi-walled CNTs (MWCNT), and hybrid single-walled and multi-walled CNTs (SMWCNT), respectively. The SMWCNT shows good electrocatalytic properties to ractopamine and salbutamol, and the 1:1 is the optimized SWCNT:MWCNT ratio for SMWCNT preparation. This synergistic effect might be caused by more compact structure between SWCNT and MWCNT resulting in higher electroactive CNTs concentration on the electrode surface. When the results of using differential pulse voltammetry (DPV) with that of UV-visible spectroscopy are compared, DPV is more suitable for simultaneous determination of target species. High sensitivity of 86,917 mu A mM(-1) cm(-2) and 65,842 mu A mM(-1) cm(-2); low detection limit of 0.05 mu M and 0.1 mu M (S/N = 3); was estimated by amperometry for ractopamine and salbutamol, respectively. Simultaneous determination of ractopamine and salbutamol was taken in pork samples with the average recoveries of 98.7% and 97.1%, respectively. It is stable without significant change at room temperature for the observation more than 30 days. (c) 2012 Elsevier B.V. All rights reserved.