冻干白蛋白中水分含量检测方案(卡氏水分测定)

Weekly Application Note Category Coulometric Karl Fischer Titrator AQ series Pharmaceuticals Water content in lyophilized albumin by Solvent extraction method & Cosmetics Outline Water contained in lyophilized albumin is extracted into anhydrous methanol and is determinedaccurately by Coulometric KF titration method using the AQUACOUNTERQ AQ-2200 or AQ-300Titrator. Reagents Anode solution HydranalQ Coulomat AG Cathode solution HydranalQ Coulomat CG (Not necessary when F or E type is used.) Extraction solvent Dehydrated methanol *Hydranal@ series KF reagents are available from Sigma-Aldrich Co. http：//www.sigmaaldrich.com. Instruments Models High-end Coulometric KF Titrator AQ-2200S/F or E Or Compact Coulometric KF Titrator AQ-300 人AQ-300 AQ-2200F Procedure ① Measure water content in dehydrated methanol to be used as extraction solvent.(... A ppm) ②Weigh the total weight of the vial containing the sample. (...T) ③ Inject approx.4mL of the dehydrated methanol into the vial and weigh it. (... S) ④ Obtain the size of the methanol injected by subtracting Tfrom S. (... B) ⑤SShake the vial to accelerate extraction of the water. After leaving for an hour， draw thesupernatant liquid (extraction liquid) into a glass syringe. ⑥ Weigh the syringe， touch the：SAMPLEkey and inject the extraction liquid into the cell. ⑦TTouch theTITRATIONkey to start a measurement. The end point is determined according tothe Interval Time set to 20 seconds. ⑧Weigh the syringe again. The difference between before/after injection is the weight of theliquid added. Touch theSizekey to enter the size. 9 After finishing the measurement， wash and dry the vial and then weigh it. (...E) The size of albumin contained in the vial is obtained by extracting E from T. (... C) Condition parameters Cal Mode 7 Interval Timer 20 sec Current MEDIUM Points In order to increase the precision of measurement， well-dehydrated solvent should be used asextraction solvent. 本实验采用库伦法对冻干白蛋白中所含的水进行测试，将样品溶解于甲醇中，样品中的水分被提取到无水甲醇中，并使用AQ系列进行测试。