| 邻氨基苯甲酸电化学修饰电极及其铅的测定 |
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| 中文关键词 铅 玻碳电极 邻氨基苯甲酸 |
| 英文关键词 glassy carbon electrode anthranilic acid modification determination of trace lead |
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| 中文摘要 |
| 本文提出用电化学方法制作邻氨基本甲酸修饰玻碳电极,修饰液为50ml水溶液,内含邻氨基苯甲酸0.3g,36%甲醛0.3g,NaOH 0.3g;扫描的电位范围为-0.1—+1.3V(vs.SCE);扫速100mV/s和扫描时间5min.研究了铅在该电极上的阳极溶出伏安特性,铅在该电极上的氧化还原过程是不可逆反应.电极对铅的测定灵敏度比未修饰玻碳电极大大提高,重现性也好,测定12次的相对标准偏差为1.8%,电极可用于水中痕量铅的测定,最佳的测定条件是:底液为0.05mol/L KCl(pH=2—8),富集电位-0.9V(vs.SCE),富集时间2min.常见离子不干扰铅的测定.铅(Ⅱ)浓度为1—3ng/ml时,测定回收率为96—102%,定量测定的下限是0.2ng/ml. |
| 英文摘要 |
| Reported in this paper is a method for preparation of a glassy -carbon electrode modified with anthranilic acid electrochcmically. The modification wag carried out in a 50 ml of aqueous solution containing 0.3g anthranilic acid, 0.3g formaldehyde and 0.3g NaOH, by -sweeping the glassy carbon 'electrode potential between 0.1 and + 1.3 V (vs SCE) with scan rate of 100 mV/s for 5 min under stirring. The behaviour of lead on this electrode was also investigated by anodic stripping voltammetry. The redox process of the lead on this modified electrode was irreversible. The sensitivity of, this electrode for lead was much higher than that of immodified one. The modified electrode showed excellent reproducibility with a relative standard deviation of ca. 1.8%(n=12). It was applied to determination of trace lead(II) in water and the optimal conditions were 0.05mol/L KG (pH= 2-8) as supporting electrolyte, -0.9V (vs.SCE) and 2 min for pre-electrolysis. The determination of lead didnot be interfered by common ions, and obtained a 96-102% recovery for 1-3 ng/ml of lead(Ⅱ). The lower limit of the quantitative determination of lead was 0.2 ng/ml. |
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