采用电位法测定氟苯尼考及其制剂的含量

Determination of Florfenicol Content by Potentiometric Titration

用电位法[1] 测定氟苯尼考的含量。将本品用乙醇溶解 ,加 50 %氢氧化钾溶液 2 0 ml,加热回流 4h,冷却 ,加水 1 0 0 ml稀释 ,用稀硝酸中和后 ,再加稀硝酸 7.5ml,照电位滴定法 ,用银 -玻璃电极 ,以硝酸银滴定液 ( 0 .1 mol/ L)滴定。测得氟苯尼考预混剂回收率为 99.0 %,RSD为 0 .41 %,注射液回收率为 1 0 0 .0 %,RSD为 0 .2 8%,该法准确度高 ,重现性好。

The principle of potentiometric titration to determine florfenicol is to measure the potential variation of indicator electrode caused by the combination of Cl - and Ag +. The Cl - is dissociated from florfenicol which is heated and refluxed in alkaline circumstance. Dissolve the sample in alcohol, add 20ml of 50% potassium hydroxide solution, heat and reflux for 4 hours, cool, dilute with 100ml of distilled water, neutralize with diluted nitric acid , add 7.5ml of diluted nitric acid, choice silver glass electrode and titrate with silver nitrate solution (0.1mol/L). The test result shows recovery 99.0% and RSD 0.41%for florfenicol premix; recovery 100.0% and RSD 0.28% for florfenicol injection. This assay approach is high in accuracy and well in reappearance.