Based On Carbon Nanotubes Or Poly P-aminobenzene Sulfonic Acid Modified Graphite Electrode For The Detection Of Ractopamine Or Salbutamol

Salbutamol and ractopamine are belongs to the compounds of’lean meat’. They are often used illegally because they can reduce animal fat. People will appear symptoms of poisoning, and even cause death after eating a higher amount of salbutamol or ractopamine residues in animal products. Therefore, it is necessary for them to establish a sensitive, rapid, low cost and simple detection method. In this paper, the cheap graphite electrode was modified by carbon nanotubes or poly p-aminobenzene sulfonic acid, and it was applied to detect salbutamol or ractopamine. The main researches are as follows:1. Sensitive detection of salbutamol on the carbon nanotubes modified graphite electrode (MWNTs/SG)The carbon nanotube was prepared by CVD and it was dispensed on graphite electrode surface to obtain the modified electrode of MWNTs/SG. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used to analyse salbutamol quantitatively. The results indicated that a sensitive oxidation peak appeared at+0.62 V for salbutamol, and the peak current was linear to its concentration in the range of 8.00×l0-7～0.20×l0-5 mol/L under the optimal conditions of the preparation of carbon nanotubes and in the phosphate buffer solution of pH 7.00. The linear regression equation was ipc(μA)=4.204+1.704×c (μmol/L) with the correlation coefficient of 0.992 and the determination limit was as low as 5.00×10-7 mol/L. In addition, the modified electrode of MWNTs/SG was applied to the determination of actual samples with the recovery of 90.0～106.0%.2. The detection of ractopamine on the poly p-aminobenzene sulfonic acid modified graphite electrode (PABSA/SG)The poly p-aminobenzene sulfonic acid modified graphite electrode was prepared by cyclic voltammetry and the preparation conditions were optimized in detail. The electrochemical behavior of ractopamine on modified electrode was studied by differential pulse voltammetry (DPV). The results indicated that a oxidation peak at appeared at+0.55V for ractopamine in the PBS of pH 7.50, and the peak current was linear to its concentration in the range of 5.00×10-7～5.00×10-5 mol/L. The linear regression equation was ipc(μA)= 15.026+0.402xc (μmol/L) with correlation coefficient of 0.998 and the determination limit was as low as 5.00×10-7 mol/L. In addition, the modified electrode showed excellent reproducibility and stability, and it could be applied to the determination of actual samples with the recovery of 92.5～108.7%.