【摘要】 研究了在稀H2SO4介质中,痕量甲醛催化KBrO3氧化乙基橙褪色反应的适宜条件和影响因素,建立了测定痕量甲醛的动力学光度法。方法采用固定时间法于507 nm波长处测量体系的吸光度,在适宜条件下,ΔA与甲醛质量浓度具有良好的线性关系,方法的线性范围为0~0.24 mg/L,检出限为0.004 mg/L。该方法用于饮料、废水和废气中痕量甲醛的测定,测定结果的相对标准偏差RSD≤3%(n=6),回收率为102%。更多还原

【Abstract】 A kinetic spectrophotometric method for the determination of trace formaldehyde was proposed, which is based on the kinetic effect of formaldehyde on the discoloring reaction of ethyl orange oxidized by potassium bromate in the dilute sulfuric acid solution. Under the optimum conditions, the decrease in absorbance was measured at 507 nm at a fixed time interval, and the linear range for formaldehyde is 0～0.24 mg/L with a detection limit of 0.004 mg/L. The method was applied to the determination of trace formaldehyde in drink and waste water and air samples with satisfactory results of RSD less than 3%(n=6) and recovery of 102%.更多还原