Preparations And Applications Of Fluorine Ion-Selective Electrode In Fluoroquinolone Drug's Determination

Fluoroquinolone Drug is a new kind of anti-inflammation drugs. Because of their wide clinical use, more and more concerned analytical methods were reported. However, oxygen flask combustion-fluorine ion selective electrode and a novel kind of PVC wire-coated membrane electrode were not reported. Then we have studied these two methods.Part ⅠDetermination of Fluorine in Fluoroquinolone Drugs by Means of Oxygen Flask Combustion and Fluorine Ion Selective Electrode Objects: To determine the content of fluorine in fluoroquinolone.Methods: Prepare fluorine reference solution whichF-concentration is 5.0×10-2mol/L and TISAB.The samples were organically broken up by oxygen flask combustion method. NaOH solution (0.1%) was used to absorb HF. The end of ashless filter paper was ignited. Insert it in flask quickly to make the plunger tight. The flask was revolved and sloped 45°to seal the solution with the plunger. Then shake the flask vigorously and keep it in room temperature for 15min. Add a drop of bromocresol purple indicator in the absorptive solution and adjusted it to become yellow (pH5.3). The solution was added TISAB 25mL, and then added water to 250mL.Stepwise diluted F- reference solution to 1.0×10-2~1.0×10-7mol/L. The sample solution was used to the battery: F--ISE/sample solution/SCE. The potentials were regarded as ordinate and the concentrations of F- as abscissa to prepare standard curve. Prepare reference solutions (10-3,10-4,10-5mol/L) to carry out precision test. Prepare reference solution (10-4mol/L) to undergo stability test. The recovery test was determined by adding sample recovery.The potentials of sample were determined by the same method of F- reference solutions content determination. The contents of fluorine and drugs were calculated by standard curve eqation.Results: The content of fluorine in norfloxacin material was 4.635% by this method and 4.225% by Chinese Pharmacopoeia (2000 edition, the second part).Those in ciprofloxacin hydrochloride material were 4.905% and 4.653% respectively. Those in enoxacin material were 5.969% and 5.619% respectively. Those in sparfloxacin material were 9.676% and 8.855% respectively.Conclusions: The means of oxygen flask combustion and fluorine ion-selective electrode are sensitive, accurate, stable, easy and can be used to determine the content of fluorine in fluoroquinolone.Part ⅡDetermination of Fluoroquinolone Drugs by Means of Oxygen Flask Combustion and Fluorine Ion-Selective electrode Objects: To determine the content of fluoroquinolone in material and the preparations including norfloxacin, ciprofloxacin hydrochloride, enoxacin and sparfloxacin.Methods: Determine the contents of fluoroquinolone in material and preparations according to the methods ofPart Ⅰ.Results: The method of oxygen flask combustion and fluorine ion-selective electrode (the content of preparations was the percents of their labelled weighs) : The contents of norfloxacin in material and capsules(three batches) were 99.86%, 101.6%, 101.7%, 101.4% and 99.91%, 101.8%,101.4%, 102.2% by Chinese Pharmacopoeia method. Those in ciprofloxacin hydrochloride material and tablets (three batches) were 99.73%, 100.2%, 100.5%, 100.9% and 99.51%, 101.6%, 101.1%, 100.5% respectively. Those in enoxacin material and tablets (three batches) were 99.98%, 99.40%, 102.1%, 101.0% and 99.65%, 98.51%, 103.5%, 100.8% respectively. Those in sparfloxacin material and tablets (three batches) were 99.76%, 100.0%, 100.8%, 99.84%, and 99.41%, 99.51%, 101.6%, 100.8% respectively.Conclusions: The contents of fluoroquionolone in material and preparations by means of oxygen flask combustion and fluorine ion-selective electrode are comply with by Chinese Pharmacopoeia (2000 edition, the second part) method.Part ⅢStudy and Application of Novel Wire-Coated ElectrodeObjects: To prepare a novel PVC wire-coated membrane eletrode and determine the cnntents of fluoroquinolone in preparations.