摘要
紫外光对NO_3^-水溶液有很强的还原作用,能定量生成NO_2^-。该还原作用与光源强度、光照距离、照射时间、酸度、温度、共存物质等因素有关。选择合适条件能在10分钟内100%还原NO_3^-为NO_2^-。建立了优越得多的紫外光还原法代替镉柱还原法,成功地测定了水样中NO_3-。所得结果与镉柱还原法相符,相对标准偏差±1%,标准回收率98～99%。
Nitrate in aqueous solution can be intensely reduced by irradiation with a high-pressuremercury-arc lamp. Under suitable conditions, nitrate may be quantitative into nitrite within10 minutes Factors affecting the reduction are discussed. A better photochemical reduction methodhas been developed to replace the cadmium-reduction method for determination of nitrate inwater. The method gives results comparable to those obtained by the official method The rela-tive standard deviations were±1% and the standard recoveries, 98-99%.
关键词
硝酸根
还原作用
紫外线
水
光度法
mitrate
nitrite
ultraviolet irradiation
reduction
nitrate determination
