催化光度法测定微量亚硝酸根的研究  

Kinetic Spectrophotometric Determination of Trace Nitrite

作　　者：曹秀云 

机构地区：[1]江西省化学工业学校,江西南昌330000

出　　处：《江西化工》2012年第2期77-82,共6页Jiangxi Chemical Industry

摘　　要：基于在0.4 mol/L硫酸介质中,亚硝酸根对溴酸钾氧化乙基橙褪色反应的催化作用,建立了一种在恒温水浴50oC下测定亚硝酸根含量的新方法。在508 nm处,亚硝酸根的含量在0.013～0.2μg/mL范围内与乙基橙吸光度的减小(lgA0/A)呈线性关系,检出限为0.02μg/mL。研究发现温度仅对反应的初始速率有较大的影响,但在8～15 min反应时间范围内,ΔA的值趋于恒定,温度及时间几乎无影响,克服了实验中ΔA随时间和温度变化的影响。本方法简便快速,灵敏度及选择性较高,用于环境水样中痕量NO2-的测定,结果满意。A simple sensitive and selective kinetic spectrophotometric method for the determination of trace nitrite at constant temperatμre（50 ℃） was developed,based on its catalytic effect in the reaction between Ethyl orange and potassiμm bromate.The reaction is followed spectrophotometrically by measμring the change in absorbance at 508 nm at a fixed time of 10 min from initiation of the reaction.The linear range and the limit of detection is 0.02 ~0.3μg·mL-1and 0.02 μg·mL-1.The reaction temperatμre and time had significant effects on the initial reaction rate,but the value of ΔA remained constant dμring 8 min to 15min.The method is simple,rapid,sensitive and selective.It has been applied to the direct determination of nitrite in water samples with satisfactory results.

关 键 词：亚硝酸根 乙基橙 溴酸钾 催化光度法 

分 类 号：O657.3[理学—分析化学]