探究了十六烷基溴化吡啶GFDA2（HPB）存在下铬天青B与维生素B₁₂的缔合反应，建立了测定药物中维生素B₁₂的高灵敏共振光散射（RLS）新方法。在pH 7.69的弱碱性溶液中，维生素B₁₂与铬天青B-HPB反应，以静电引力相互作用生成三元离子缔合物，使RLS信号明显增强，在最大RLS峰371 nm波长处，体系的RLS增强强度（ΔI_RLS）与0.003~2.71 mg/L范围内的维生素B₁₂的质量浓度呈很好的线性关系，检出限为0.002 5 mg/L。该方法简便、快速、准确、灵敏，用于药物中维生素B₁₂的测定，加标回收率为98.2%~102%，相对标准偏差RSD（n=5）为1.5%~1.8%。

The association reaction between chrome azure B and vitamin B₁₂ is studied in the presence of 1-hexadecylpyridinium bromide (HPB),and a highly sensitive and new resonance light scattering (RLS) method is established for the determination of vitamin B₁₂ in drugs.In a weak alkaline solution of pH=7.69,vitamin B₁₂ reacts with chrome azure B-HPB to form a ternary ionic associate complex by electrostatic attraction,which leads to a significant enhancement of RLS signals.At the maximum RLS peak of 371 nm wavelength,the system's RLS enhancement intensity (ΔI_RRS) shows a good linear relationship with the mass concentration of vitamin B₁₂ in the range of 0.003-2.71 mg·L^-1,and the detection limit is 0.002 5 mg·L^-1.This method exhibits simple,rapid,accurate and sensitive.As it is applied to the determination content of vitamin B₁₂ in drugs,the recovery of standard addition is 98.2%-102%,and the relative standard deviation RSD(n=5) is 1.5%-1.8%.

何树华(1971-),女,学士,教授,研究方向为分子光谱分析,heshuhua20182019@163.com