摘要
在稀盐酸介质中 ,维多利亚蓝B(VBB)的最大吸收峰位于 6 13nm ,当与NO- 2 反应后发生颜色变化 ,最大吸收峰红移 ,以试剂空白为参比 ,可观察到在 6 39nm处出现一新的最大吸收峰 ,同时在 5 6 0nm处发生褪色反应 ,最大褪色波长和最大吸收波长处吸光度均与溶液中NO- 2 的浓度成正比 ,其线性范围在 0～ 2 0 μg/ 2 5mlNO- 2 ,摩尔吸光系数分别为ε56 0 =2 .96× 10 4 L·mol- 1·cm- 1,ε6 39=3.2 3× 10 4 L·mol- 1·cm- 1,用双波长叠加法ε56 0 +6 39=6 .19× 10 4 L·mol- 1·cm- 1,相关系数为 0 .9999。由于显色反应在较强的酸性介质中进行 ,方法具有良好的选择性 ,用于环境水中微量NO- 2 的测定 ,结果满意。
An absorption maximum at 613nm was observed for victoria blue B (abbreviated as VBB) in a dilute hydrochloric acid medium. When VBB was reacted with NO - 2, the absorption maximum was shifted to 639nm ( vs . reagent blank), and simultaneously an obvious color fading of VBB was observed at 560nm. Linear relationships between the variation of absorbances and the concentrations of nitrite ion (0～20μg per 25ml of solution) were obtained both at 639nm and 560nm, with molar absorptivities of 3.23×10 4L·mol -1 ·cm -1 and 2.96×10 4L·mol -1 ·cm -1 respectively. By applying the method of double wavelength measurement, the molar absorptivity ( ε 560,639 ) was raised to 6.19×10 4L·mol -1 ·cm -1 . The corelation coefficient was found to be 0.9999. Since the reaction was carried out in an acidic medium (0.02mol·L -1 HCl), satisfactory selectivity was achieved. The proposed method has been used satisfactorily in the determination of NO - 2 in environmental water samples.
出处
《理化检验（化学分册）》
CAS
CSCD
北大核心
2002年第5期217-219,222,共4页
Physical Testing and Chemical Analysis(Part B:Chemical Analysis)
