[Objectives]This study was conducted to compare the accuracy and detection speed of high performance liquid chromatography for determining the content of doxycycline hydrochloride in doxycycline hydrochloride soluble ...[Objectives]This study was conducted to compare the accuracy and detection speed of high performance liquid chromatography for determining the content of doxycycline hydrochloride in doxycycline hydrochloride soluble powder under different chromatographic conditions, in order to improve the level of laboratory testing. [Methods] Four sets of experiments were designed through a cross-test method. The contents of doxycycline hydrochloride in the raw materials of doxycycline hydrochloride and doxycycline hydrochloride soluble powder were determined by changing the chromatographic column and mobile phase conditions, and the feasibility and practicability of the four methods were judged by comparing the detection results through data and chromatographic signal processing. [Results] The content of doxycycline hydrochloride in finished doxycycline hydrochloride soluble powder and the raw materials of doxycycline hydrochloride could be accurately determined under the four chromatographic conditions, of which the experimental group using Agilent C18 column and the mobile chromatography conditions of finished doxycycline hydrochloride soluble powder had the shortest retention time. [Conclusions] The high performance liquid chromatography method using Agilent C18 chromatographic column and mobile phase chromatographic conditions of finished doxycycline hydrochloride soluble powder products can quickly and accurately determine the content of doxycycline hydrochloride in doxycycline hydrochloride soluble powder.展开更多
Effects of column temperature and flow rate on separation of organic acids were studied by determining nine low-molecular-weight organic acids on reversed- phase C18 column, using high performance liquid chromatograph...Effects of column temperature and flow rate on separation of organic acids were studied by determining nine low-molecular-weight organic acids on reversed- phase C18 column, using high performance liquid chromatography (HPLC) with a wavelength of UV (ultraviolet) 214 urn and a mobile phase of 18 mmol L-1 KH2PO4 buffer solution (pH 2.1). The thermal stability of organic acids was determined by comparing the recoveries of organic acids in different temperature treatments. The relationships between column temperature, flow rate or solvent pH and retention time were analyzed. At low solvent pH, separation efficiency of organic acids was increased by raising the flow rate of the solvent because of lowering the retention time of organic acids. High column temperature was unfavorable for the separation of organic acids. The separating effect can be enhanced through reducing column temperature in organic acid determination due to increasing retention time. High thermal stability of organic acids with low concentrations was observed at temperature of 40 ℃-45℃. Sensitivity and separation effect of organic acid determination by HPLC were clearly improved by a combination of raising flow rate and lowering column temperature at low solvent pH.展开更多
文摘[Objectives]This study was conducted to compare the accuracy and detection speed of high performance liquid chromatography for determining the content of doxycycline hydrochloride in doxycycline hydrochloride soluble powder under different chromatographic conditions, in order to improve the level of laboratory testing. [Methods] Four sets of experiments were designed through a cross-test method. The contents of doxycycline hydrochloride in the raw materials of doxycycline hydrochloride and doxycycline hydrochloride soluble powder were determined by changing the chromatographic column and mobile phase conditions, and the feasibility and practicability of the four methods were judged by comparing the detection results through data and chromatographic signal processing. [Results] The content of doxycycline hydrochloride in finished doxycycline hydrochloride soluble powder and the raw materials of doxycycline hydrochloride could be accurately determined under the four chromatographic conditions, of which the experimental group using Agilent C18 column and the mobile chromatography conditions of finished doxycycline hydrochloride soluble powder had the shortest retention time. [Conclusions] The high performance liquid chromatography method using Agilent C18 chromatographic column and mobile phase chromatographic conditions of finished doxycycline hydrochloride soluble powder products can quickly and accurately determine the content of doxycycline hydrochloride in doxycycline hydrochloride soluble powder.
文摘Effects of column temperature and flow rate on separation of organic acids were studied by determining nine low-molecular-weight organic acids on reversed- phase C18 column, using high performance liquid chromatography (HPLC) with a wavelength of UV (ultraviolet) 214 urn and a mobile phase of 18 mmol L-1 KH2PO4 buffer solution (pH 2.1). The thermal stability of organic acids was determined by comparing the recoveries of organic acids in different temperature treatments. The relationships between column temperature, flow rate or solvent pH and retention time were analyzed. At low solvent pH, separation efficiency of organic acids was increased by raising the flow rate of the solvent because of lowering the retention time of organic acids. High column temperature was unfavorable for the separation of organic acids. The separating effect can be enhanced through reducing column temperature in organic acid determination due to increasing retention time. High thermal stability of organic acids with low concentrations was observed at temperature of 40 ℃-45℃. Sensitivity and separation effect of organic acid determination by HPLC were clearly improved by a combination of raising flow rate and lowering column temperature at low solvent pH.
