摘要
基于溴酸钾在硫酸介质中可氧化苯酚红，甲醛的加入催化该氧化反应的进行，从而使溴酸钾氧化苯酚红的速度明显加快，据此建立了测定食品中痕量甲醛的新催化动力学分光光度法，并研究了该催化褪色反应的最佳动力学条件和参数。在测定波长380 nm下，测定方法的线性范围0.02～0.32滋g/mL，检出限为6.10×10^-9 g/mL。催化反应为动力学零级反应，表现活化能为38.87 kJ/mol，催化反应速率常数k=9.1×10^-4s^-1。运用所建立的方法测定食品中痕量甲醛，相对标准偏差小于3.9%，回收率在96.3%～105.5%，表明该方法测得的结果与乙酰丙酮光度法所测结果一致。
A catalytic spectrophotometric method for the determination of trace formaldehyde is established based on the inhibitory effect of formaldehyde on the oxidation of phenol red by potassium bromate in H2SO4 medium. The optimum kinetic condition of the catalytic reaction has been investigated. The wavelength for the determination is 380 nm, and the linear range for determination of formaldehyde is 0.02~0.32 μg/mL with the detection limit of 6.10×10^-9 g/mL.v The results from the studies suggest that the catalytic reaction is zero-or-der and the apparent activation energy of this reaction is 38.87 kJ/mol,and the apparent rate constant is k=9.1×10^-4s^-1. The procedure has been used to determine formaldehyde in foods, with the relative standard devi-ation of below 3.9%and the average recovery of 96.3 %~105.5 %. Results obtained by this method are con-sistent with the results found by the acetylacetone photometry.
出处
《南通职业大学学报》
2015年第3期72-75,共4页
Journal of Nantong Vocational University
关键词
催化动力学
光度法
甲醛
苯酚红
溴酸钾
catalytic kinetic
spectrophotometry
formaldehyde
phenol red
potassium bromate
