摘要
利用醛基与羟胺在酸性条件下的加成反应产物乙醛酸肟和乙二醛二肟的不同紫外吸收峰,用双波长法同时测定溶液中的乙醛酸和乙二醛。结果表明,乙醛酸在 0.03~0.156 g·L-1范围内符合比耳定律,其回归方程为 y=0.109 4x-0.003 7,r=0.999 9(n=5),乙二醛在 0.1~0.5 g·L-1范围内符合比耳定律,其回归方程为y=0.223 11x-0.023 5,r=1.000 0(n=5)。乙醛酸和乙二醛质量比大于1,乙醛酸的回收率为 96.2%~101.5%,乙二醛的回收率为 101.6%~106 8%。方法操作简便、经济、精密度较好。
In the preparation of glyoxylic acid, the yield and quality of the objective product are qualified by the determination of contents of glyoxylic acid and glyoxal in the reaction mixture. Based on the respective formation of glyoxylic acid oxime (HON=CH-COOH) and glyoxime (HON=CH-CH=NOH) by the addition reaction with hydroxylamine and on the different absorption of the two products in the UV spectral region, a simultaneous indirect dual-wavelength spectrophotometric determination of glyoxylic aicd and glyoxal was proposed. Linearity for the determination of glyoxylic acid and glyoxal were found in the ranges of 0.03~0.156 g·L^(-1) and 0.1~0.5 g·L^(-1) respectively and their regression equations were also calculated as follows: y=0.109 4x-0.003 7, r=0.999 9, n=5 (for glyoxylic acid), and y=0.223 1x-0.023 5, r=1.000 0, n=5 (for glyoxal). In case the ratio of mass of glyoxylic acid to glyoxal is larger than 1, no interference was found each other in the determination. Under the optimum conditions, recoveries for glyoxylic acid were in the range of 96.2%~101.5%, and for glyoxal in the range of 101.6%~106.8%.
出处
《理化检验（化学分册）》
CAS
CSCD
北大核心
2005年第3期199-202,共4页
Physical Testing and Chemical Analysis(Part B:Chemical Analysis)
关键词
紫外吸光光度法
加成反应
乙醛酸
乙二醛
乙醛酸肟
乙二肟
UV-spectrophotometry
Addition reaction
Glyoxylic acid
Glyoxal
Glyoxylic acid oxime
Glyoxime
