在pH 6.70的弱酸性溶液中，乙基紫与地奥司明反应生成一种二元配合物，在紫外光区345 nm处产生1个较强的正吸收峰，在可见光区594 nm处产生1个较强的负吸收峰，在此二波长处，地奥司明的质量浓度在0.3~15.2 mg/L范围内与吸光度的绝对值（|A|）呈线性关系并服从朗伯-比尔定律，其表观摩尔吸光系数（κ）为1.88×10⁴ L/（mol·cm）（正吸收）和3.81×10⁴ L/（mol·cm）（负吸收），检出限为0.24 mg/L （正吸收）和0.18 mg/L （负吸收）。当以负吸收为参比波长、正吸收为测定波长、用双波长法测定时，其线性范围不变，表观摩尔吸光系数（κ）为5.70×10⁴ L/（mol·cm），检出限为0.11 mg/L。由此建立了测定地奥司明的紫外-可见吸收光谱法。该方法可用于市售地奥司明药物中地奥司明的测定。

In a weak acidic solution with a pH of 6.70,ethyl violet can react with diosmin to form a binary complex,resulting in that a strong positive absorption peak is generated at 345 nm in the ultraviolet region,and a strong negative absorption peak is igenerated at 594 nm in the visible region.At these two wavelengths,the mass concentration of diosmin is linearly related to the absolute value of absorbance (|A|) in the range of 0.3 to 15.2 mg/L,which obeys lambert-beer's law.Their apparent molar absorption coefficients (κ) are 1.88×10⁴ L/(mol·cm) (positive absorption) and 3.81×10⁴ L/(mol·cm) (negative absorption) respectively.Their detection limits are 0.24 mg/L (positive absorption) and 0.18 mg/L (negative absorption).If the negative absorption wavelength is used as reference wavelength,the positive absorption wavelength is used as determination wavelength and a dual-wavelength absorption spectrometry is used to determine diosmin,its linear range remains unchanged,its apparent molar absorption coefficient (κ) is 5.70×10⁴ L/(mol·cm) and its detection limit is 0.11 mg/L.Based on this,the ultraviolet-visible absorption spectrometry is established for the determination of diosmin.The method can be applied to the determination of diosmin in commercially available diosmin drugs with the satisfactory results.

庞向东(1962-),男,理学学士,副教授,研究方向为分子光谱分析,cspxdfxsch123456@163.com