| After processing to the carbon paste electrode, the pre-anodized inlaying ultra-thin carbon paste electrode(PAIUCPE), a kind of electrode emerging in recent years, was constructed, in recent years, the research on this was active. The PAIUCPE was concerned by electrochemistry and electroanalytical chemistry workers, due to its wide potential window, good electrical conductivity, simple preparation method, easy to update and low cost. It has been developing rapidly since PAIUCPE appeared, it has been used in medicine, food, biological, environmental and other industries. So the study on the electrochemical behavior of material in PAIUCPE and the reaction mechanism had great significance, the development of new PAIUCPE was a big challenge for us. 316L-PAIUCPE was constructed using 316 L stainless steel as a matrix, applied cyclic voltammetry to determine simultaneously various drugs, perfect results were gained, and the reaction mechanism was studied. For the material difficult to separate, by adding hexadecylpyridinium chloride(CPC), it is a kind of cationic surfactant, to realize the material separation. using the electrode, we did the following a series of work: 1. Simultaneous determination dopamine, uric acid and tryptophan at pre-anodized ultra-thin carbon paste nickel chromium molybdenum alloy electrodeIn this paper, the pre-anodized inlaying ultra-thin carbon paste electrode was made using nickel chromium molybdenum alloy as a matrix, a new way to simultaneously determine dopamine(DA), uric acid(UA) and tryptophan(Trp) was found by means of the electrode. And explored the mechanism of acidity on the DA, UA and Trp oxidation peak currents. The test results show that, on different p H conditions, the intensity of hydrogen bonding or electrostatic interactions between different acid-base species of DA, UA, Trp and the negatively-charged oxygen-containing functional groups at the surface of IV 316L-PAIUCPE resulted in that the size of their oxidation peak currents varied with the p H. In addition, it was also discussed that how the reaction on the working electrode was influenced by the reaction on the auxiliary electrode. Under the optimized experimental conditions, the oxidation peak currents were proportional to the concentrations of DA, UA and Trp in the range of 0.40~200μmol·L-1, 0.50~150μmol·L-1 and 0.10~200μmol·L-1 with the detection limits of 0.08μmol·L-1, 0.05μmol·L-1 and 0.14μmol·L-1 in PBS buffer solution(p H=5.0), respectively. This method presented was successfully employed for determination the contents of DA in injection, UA in human urine and Trp in human serum. 2. Simultaneous determination levodopa, xanthine and adenine at pre-anodized ultra-thin carbon paste nickel chromium molybdenum alloy electrodeThe pre-anodized inlaying ultra-thin carbon paste electrode was made using nickel chromium molybdenum alloy as a matrix(316L-PAIUCPE). A strategy for simultaneous determination of levodopa(LD), xanthine(Xa) and adenine(A) was reported based on 316L-PAIUCPE. The charge properties of active groups on electrode surface, hydrogen bond formation and catalysis, the reaction on auxiliary electrode, molecular configuration, distribution of different species and the changes of oxidation peak potential with p H were used to discuss in detail the effect of acidity on the oxidation peak currents. Their linear ranges were 0.65~104μmol·L-1, 0.10~100μmol·L-1and 0.30~90μmol·L-1, the detection limits were 0.13μmol·L-1, 0.08μmol·L-1 and 0.09μmol·L-1 in PBS buffer solution(p H=3.0), respectively. This method presented was successfully employed for determination the contents of LD, Xa and A in different samples. 3. Pre-anodized ultra-thin carbon paste nickel chromium molybdenum alloy electrode for simultaneous determination of uric acid and paracetamol in the presence of surfactantThe pre-anodized inlaying ultra-thin carbon paste electrode was constructed using nickel chromium molybdenum alloy as a matrix(316L-PAIUCPE), in the present of cationic surfactant hexadecylpyridinium chloride(CPC), the various signal response of uric acid(UA) and acetaminophen(AC) were explored by 316L-PAIUCPE and the effect mechanism of CPC on their electrical signals were discussed in detail. The test results show that, in the present of CPC, the oxidation potential separation of UA and AC increased by 144 m V, the separation and determination of the two can be realized, and CPC have an inhibitory action on the oxidation peak current of UA and AC. In addition, the reasons for the increase of oxidation peak potential separation and the decrease of oxidation peak current were explained in detail. Based on the optimization of CPC concentration, p H, scan rate, a new strategy was found for simultaneous determination of UA and AC. The result show that the oxidation peak currents were increased linearly with the concentrations of UA and AC in the range of 0.30~100μmol·L-1 and 0.50~100μmol·L-1 with the detection limits of 0.06μmol·L-1 and 0.08μmol·L-1 in PBS buffer solution(p H=6.0), respectively. This method was successfully used to determine the contents of UA in human urine, AC in medicine. 4. Pre-anodized ultra-thin carbon paste nickel chromium molybdenum alloy electrode for simultaneous determination of etamsylate and acetaminophen in the presence of surfactantElectrochemical behaviors of etamsylate(ETM) and acetaminophen(AC) were researched in the pre-anodized ultra-thin carbon paste nickel chromium molybdenum alloy(316L-PAIUCPE) by cyclic voltammetry. In the present of cationic surfactant hexadecylpyridinium chloride(CPC), electrochemical behavior of UA and AC was researched in the pre-anodized ultra-thin carbon paste nickel chromium molybdenum alloy(316L-PAIUCPE). The oxidation potential separation of them increased by 68 m V, and CPC has a strong sensitizing effect to the oxidation peak current of ETM and an inhibitory action on the oxidation peak current of AC. In addition, the reasons for the change of the peak potential separation and the peak currents were explained in detail. Based on the optimization of CPC concentration, p H, scan rate, a new way was found for the simultaneous determination of ETM and AC. The oxidation peak currents were and the concentrations of ETM and AC have a linear realationship in the range of 0.30~100μmol·L-1 and 0.50~200μmol·L-1 with the detection limits of 0.18μmol·L-1, 0.06μmol·L-1 in PBS buffer solution(p H=5.0), respectively. This method was successfully employed to determine the contents of ETM and AC in medicine. |
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