THE PREPARATION AND EVALUATION OF ULTRAMICRO-SENSOR MODIFIED POLYMETHACRYLOYLACETC

研制了一种用于金属离子检测的聚甲基丙烯酰丙酮(PMAA)多孔超微电极。在铂微电极的尖端填充了一种多孔碳材料，该电极的顶部有一个空腔。将多孔超微电极浸泡在含有PMAA和邻苯二甲酸二乙基己酯的四氢呋喃溶液中，在室温下烘干过夜。在最佳条件下考察了金属离子浓度与氧化峰电流的关系。铁离子浓度在0.01 mm~1 mm范围内与峰面积呈线性关系。校正曲线可用方程Y=2.42X-0.414表示，其中Y为NA的氧化峰电流，X为MM的铁离子浓度，回归系数为0.999。用该电极还可测定铜、铅、钼等离子。由于两种离子的最佳测定条件相似，因此只有铜(II)和铅(II)的混合离子才能同时测定。电极在pH 6.0的磷酸盐缓冲溶液中室温保存。用修饰电极测定的分析值在至少3个月内是恒定的

A porous ultramicro-electrode with immobilized polymethacryloylacetone(PMAA) was developed for measuring metal ions. A porous carbon material was packed into the tip of the platinum micro-electrode with a cavity at the top. The porous ultramicro-electrode was dipped in the coating tetrahydrofuran solution with PMAA and di-2-ethylhexyl phthalate and dried overnight at room temperature. The relationship between the metal ion concentrations and oxidation peak current were examined under the optimum conditions. A linear relationship was obtained in the range of 0.01 mM - 1 mM iron ion. The calibration curve could be represented by the equation Y = 2.42X -0.414, where Y is the oxidation peak current in nA and X is the iron ion concentration in mM.The regression coefficient was 0.999. By use of this electrode, Cu(II), Pb(II), and Mo(V) ions could also be deternined. The simultaneous determination was possible only for the mixture of Cu(II) and Pb(II) ions because the optimal conditions for these ions were similar to each other. The electrode was stored in a pH 6.0 phosphate buffer solution at room temperature. Analytical values determined with the modified electrode was constant for at least 3 months