甲基橙和乙基橙结构高度相似, 双组分体系中甲基橙和乙基橙浓度的分析比较困难。 本文研究了双组分染料体系中甲基橙(MO)和乙基橙(EO)浓度的分光光度测定方法, 研究结果表明, 在λ=429.00和469.50 nm, pH 12的条件下, 采用双波长分光光度法可以快速、 准确测定体系中MO和EO的浓度, 并考察了溶液中共存Na+和Cl－对测定的影响。 线性相关方程为: A429=0.003 47+0.061 cM+0.056 46 cE; A469.50=0.002 8+0.074 37 cM+0.083 94 cE, 加标回收率基本大于95%, 相对标准偏差小于2%。 NaCl的加入对该方法的加标回收率和相对标准偏差影响较小。

The high similarity of MO and EO made it difficult to measure concentration of MOD and EOD. In this paper, dual wavelength spectrophotometry was used to determinate the concentration of MOD and EOD, which was proved to be fast and accrate. 429.00 nm and 469.50 nm were selected as deternination wavelengthes at pH 12. And the influences of Na+ and Cl- on determination of MOD and EOD were surveyed. The standard equations were A429=0.003 47+0.061 cM+0.056 46 cE and A469.50=0.002 8+0.074 37 cM+0.083 94 cE. Recovery of standard additions of MOD and EOD were larger than 95%, and relative standard deviation of standard equations were less than 2%. The addition of NaCl has little effect on recovery of standard additions and relative standard deviation of this method.