Calculating freezing point of NaH2PO4-K2HPO4 mixed electrolyte solution with semi-empirical hydration model
10.16438/j.0513-4870.2019-0431
- VernacularTitle:采用半经验水化模型计算NaH2PO4-K2HPO4混合电解质溶液冰点
- Author:
Jie GAO
1
;
Xian-cheng ZHAN
2
Author Information
1. Department of Pharmacy, Fifth Affiliated Hospital of Xinjiang Medical University, Urumqi 830000, China
2. Key Laboratory of Drug Targeting and Drug Delivery Systems, Ministry of Education, West China School of Pharmacy, Sichuan University, Chengdu 610041, China
- Publication Type:Research Article
- Keywords:
freezing point;
semi-empirical hydration model;
cooling curve cryoscopy;
air humidity cryoscopy
- From:
Acta Pharmaceutica Sinica
2019;54(11):2089-2092
- CountryChina
- Language:Chinese
-
Abstract:
The methods for determination of freezing point include cooling curve cryoscopy and air humidity cryoscopy. These methods are usually influenced by many factors, such as instrumentation, environment and operators. Despite the numerous experimental methods, precise freezing point values are challenging to obtain due to time-consuming procedures, limited sample size and extensive manual work. In this study, a semi-empirical hydration model (SEHM) was developed to calculate freezing point of NaH2PO4-K2HPO4 mixed electrolyte solution. According to SEHM, the water activity of mixed electrolyte solution was calculated by molality of solutes. Then the freezing point of solution was calculated. The calculated results were compared with those obtained by cooling curve cryoscopy and air humidity cryoscopy. The results indicate that the SEHM calculations are comparable to the measurements of cooling curve cryoscopy and air humidity cryoscopy.
