Study On Rapid Detection Of Sulfonamides Residues Based On The Electroanalytical Method

Sulfonamides(SAs) is a kind of broad-spectrum antibiotic, mainly used for clinical treatment and prevention of bacterial infectious diseases, but inproper utilization will cause the SAs residues in animal body and accumulation in the human body, which can cause allergic reactions, making urinary system damaged, inhibiting leukocyte generation and even cancer, posing a threat to health. Traditional detection methods of SAs are mainly based on chromatography technology, which has many advantages, such as high accuracy and sensitivity. However, rigorous technical requirements, expensive equipments and complicated sample pretreatment process limit the technology being used in rapid detection. Electrochemistry, which is simple, fast and has high sensitivity, can achieve the scence detection and has been used in rapid detection analysis. Multiwalled carbon nanotubes(MWCNTs) have many advantages, such as large specific surface area, good electrical conductivity and biological compatibility. Based on the modified glassy carbon electrode(GCE), homemade platinum microelectrode(PME) and embedded platinum powder microelectrode, we adopt electrochemistry to detect SAs, who has electrochemical activity. Reach contents are as follows:1. Reseach on modified materials: H2O-MWCNTs, DMF-MWCNTs and carboxyl DMF-MWCNTs were used to modify glassy carbon electrode and homemade platinum microelectrode to study the feasibility of the modified electrodes. H2O-MWCNTs/GCE, DMF-MWCNTs/GCE, carboxyl DMF-MWCNTs/GCE, H2O-MWCNTs/PME, DMF-MWCNTs/PME and carboxyl DMF-MWCNTs/PME were selected out; we used nafion-MWCNTs as functional materials to prepare the the embedded Nafion-MWCNTs/PME. The optimum electrodes were carboxyl DMF-MWCNTs/GCE and carboxyl DMF-MWCNTs/PME, and electrochemistry analysis was carried out based on the embedded Nafion-MWCNTs/PME;2. Optimization research: Experimental conditions for SAs were tested, results showed that the optimum condition was pH 2.0, scan rate was 100 mV/s and concentration of carboxyl MWCNTs was 1.0×10-4 g/m L, and the the quantity of carboxyl MWCNTs for GCE and PME were 3 μL, 1μL. The response of carboxyl DMF-MWCNTs/GCE to SAs was obvious with good repeatability and stability, coexisted substance did not significantly affect carboxyl DMF-MWCNTs/GCE; the peak currents approximately trends to be stable after 6 h and the influence of some coexisted substances(glucose) cannot be ingnored when it was used to detect real samples; embedded Nafion-MWCNTs/PME had good repeatability and should be considered the influence of some coexisted substances when it was used to detect real samples.3. Research on detection of SAs: Under the optimal conditions, the carboxyl DMF-MWCNTs/GCE presented linear response to SAs in the range of 5.0×10-7 mol L-1 to 1.1×10-4 mol L-1 of sulfonamide(SA), sulfamethazine(SDZ), sulfadiazine(SM2), sulfamethoxazole(SMZ) with the average recovery of 86 %~103 %; under the same experimental condition, carboxyl DMF-MWCNTs/PME presented linear response to SAs in the range of 9.9×10-5 mol L-1 to 9.1×10-4 mol L-1 of SA, SDZ, SM2, SMZ with the average recovery of 95 %~107 %; based on embedded Nafion-MWCNTs/PME, the average recovery was 87 %~106 %.