丙二醇、甘油中水分含量检测方案(卡氏水分测定)

Inspire the Next HITACHI HIRANUMAAPPLICATION DATA Karl Fischer Titrator Data No. KF10V Water contents Drugs and Medicines -KF Volumetry Direct-Injection Propylene glycol andGlycerin 1.Abstract Water contents of drugs and medicines could be determined by Karl Fischer volumetric titrator. In volumetric titration， titrant have a titer whichmeans the capacity to react with water per 1 mL of titrant. Factor is pre-determined before sample measurement and water content of sample iscalculated from consumed titrant volume within sample measurement. When the sample is liquid， generally sample is measured by direct injection into the cell. Dehydrated methanol is used for titration solvent. Thetitration solvent may change to a composition suitable for dissolving the sample. Examples for water contents measurements of propylene glycol and glycerin performed by direct injection method are introduced here. Themeasurement method was determined with reference to Japanese Pharmacopeia. Reference 1) Japanese Pharmacopoeia Seventeenth Edition 2. Apparatus and Reagents (1)Apparatus Titrator ：Hiranuma Karl Fischer Volumetric titrator AQV-series Electrolytic cell ：Standard Cell (2)Reagents Titrant ：HYDRANAL Composite 5 (Honeywell) Titration solvent ：HYDRANAL Methanol (Honeywell) 3. Procedure (1) Fill 50 mL of titration solvent into the titration cell as shown in Fig.3.1. (2) Start blanking to attain stable background. (3) Wash the syringe with sample. (4) Draw the sample into syringe and then weigh the syringe. (5) Inject sample from rubber septum of titration cell as shown in Fig.3.2. (6) Start titration. Measurement parameter is shown in Table 4.1. (7) Weigh the syringe again and then set the difference of weight to sample size. Titration solvent Fig.3.1 Preparation of the reagents Fig.3.2 Injection of sample 4.Parameters and results Table 4.1 Parameters Condition File Cal Mode 0：Sample weight(net) X=(H-b)xFx1000/SIZE Interval Time 30 sec Max Volume 20 mL Min Feed Vol. 0.01 mL S.Timer 0 min KF Factor 5.7614 mg/mL KF Buret No. 1 KF Speed(OUT) 12 mL/min KF Speed(IN) 24 mL/min Blank Ground OFF Sample Size Input Every Time Blank Value 0 mL Unit Mode AUTO E.P Detection mV Solvent S，O，CE C.P Level 150 mV E.P Level 1 Auto Interval 0 g Table 4.2 Results of water content measurement in drugs and medicines Sample Titrant Water Water Science for a better tomorrow 日立 Propylene glycol 2.0482 0.30 1.728 843.7 Avg. 860.9 ppm KF Factor 2.0517 0.31 1.786 870.5 SD 14.9 ppm 5.7614 mg/mL 1.9240 0.29 1.671 868.5 RSD 1.73% Glycerin 6.9553 1.27 7.259 1043.7 Avg. 1047.6 ppm KF Factor 7.0613 1.29 7.374 1044.3 SD 6.3 ppm 5.7160 mg/mL 7.1525 1.32 7.545 1054.9 RSD 0.60% 5.Note (1) Sampling tools should be dried up well before use. (2) Purge and fill the titrant homogeneously into the buret. Organic solvents which have relatively high volume expansion coefficient are used as a constituent of titrant. For accurate measurement， factor titration and sample(3) measurement should be performed at the same room temperature as much as possible. Keywords：Karl Fischer， Volumetric titration， Pharmacopeia Science fora better tomorrow日立科学仪器(北京)有限公司热线电话： 热线电话：立科学仪器(北京)有限公司 本实验通过直接注入对丙二醇、甘油样品进行水含量的测定。