催化动力学分光光度法测定痕量甲醛

Catalytic Kinetic Photometric Determination of Trace Amounts of Formaldehyde

摘要: 在稀硫酸溶液中,甲醛对溴酸钾氧化罗丹明B的褪色反应有催化作用,研究了其动力学条件,建立了测定痕量甲醛的动力学分光光度法,该方法的线性范围为0.30~3.00 mg·L-1,检出限为0.15 mg·L-1,该法用于饮料中痕量甲醛的测定,标准加入回收率为95.5%~97.0%,RSD为1.8%~2.0%.

Abstract: In dilute H2SO4 medium,the color-fading oxidation of rhodamine B by KBrO3 was catalyzed by traces of formaldehyde.Linear relationship between the magnitude of decrease in absorbance measured at 540 nm and the concentration of HCHO was held in the range of 0.30-3.00 mg·L-1,with its detection limit of 0.15 mg·L-1.Kinetic conditions of the reaction were studied,and the proposed method was applied to the determination of trace amounts of HCHO in drinks.Recovery and precision of the method were tested,giving values of recovery and RSD′s (n=6) in the ranges of 95.5%-97.0% and 1.8%-2.0% respectively.