共振散射光谱法测定痕量的美他环素

在pH为11.82的B-R缓冲溶液中,美他环素与溴化十六烷基吡啶反应形成离子缔合物,导致体系的共振散射强度急剧增强,并在300nm、429nm处产生两个新的散射峰。研究了体系的光谱特征、反应的适宜条件和共存物质的影响。在最强散射波长429nm处,美他环素的浓度在0.02—12.0μg·mL^-1范围内与体系的散射强度呈现良好的线性关系,其回归方程为ΔI429nm=8.845C＋1.600（μg·mL^-1,r=0.9969）,检出限为7.5ng·mL^-1（3σ）,据此,建立了一种测定痕量美他环素的共振散射光谱法。该方法操作简便、灵敏度高,已用于美他环素胶囊和片剂的快速检测,结果满意。

Determination of Trace Metacycline by Resonance Scattering Spectrometry

In the pH11.82 B-R buffer solution,metacycline reacts with cetylpyridinium bromide to form association particles,which enhanced resonance scattering（RS）signals greatly,and produce two new RS peak at 300nm and 429nm.The spectrum character of metacycline-cetylpyridinium bromide have been investigated.The optimum reaction conditions and the effect of the foreign substances for the determination of metacycline were also studied. The RS intensity is linear to the concentration of metacycline in the range of 0.02-12.0μg·mL^-1 at the strongest RS wavelength 429nm with a regress equation of ΔI429nrn=8.845C＋1.600（μg·mL^-1,r=0.9969） and the detection limit of 7. 5ng ·mL^-l （3σ）. A new RS resonance scatterin spectrum method was described for determination of trace Metacycline. The method has high sensitivity, good selectivity,simplicity,and was applied to determination of metacycline rapidity in gelatin capsule and tablets,with satisfactory results.