In this study,simple and sensitive spectrophotometric method for the determination of folic acid(VB9)in pharmaceutical formulations was reported.The proposed method was based on the reaction between folic acid and 1,2...In this study,simple and sensitive spectrophotometric method for the determination of folic acid(VB9)in pharmaceutical formulations was reported.The proposed method was based on the reaction between folic acid and 1,2-naphthoquine-4-sulphonate(NQS)at alkaline medium(pH 11)to form deep yellow product.Beer’s law was obeyed in the range of 0.75-10.5μg/mL of folic acid at maximum wavelength of 436 nm.Under optimized reaction conditions,linear regression equation of the calibration curve was y=0.048 x+0.038(μg/mL)with a linear correlation coefficient of 0.9988.The limit of detection(LOD)and limit of quantification(LOQ)were found to be 0.159μg/mL and 0.531μg/mL,respectively.The method was successfully applied to the determination of folic acid in pharmaceutical formulations.展开更多
利用动态差示扫描量热(DSC)实验初步研究了硝基胍的热分解特性,采用Kissinger和Ozawa法计算了其热分解活化能。运用中断回归实验研究了热履历对硝基胍热分解安全性的影响,并用等温DSC实验进行了验证。利用绝热量热仪(ARC)研究了硝基胍...利用动态差示扫描量热(DSC)实验初步研究了硝基胍的热分解特性,采用Kissinger和Ozawa法计算了其热分解活化能。运用中断回归实验研究了热履历对硝基胍热分解安全性的影响,并用等温DSC实验进行了验证。利用绝热量热仪(ARC)研究了硝基胍的绝热安全性,得到了其初始分解温度,温升速率。结果表明,硝基胍是熔融分解型含能材料,其热分解为自催化反应。热履历显著影响了硝基胍的热分解安全性,降低了其起始分解温度和峰温,使其在固态时就达到较高的热分解速率。在动态DSC实验中,其起始反应温度213.8~249.9℃,峰温215.0~255.2℃,表观活化能为111.6 k J·mol^(-1)和114.2 k J·mol^(-1)。在绝热实验中,其起始反应温度为170.6℃,最大温升速率为1.414℃·min^(-1)。展开更多
文摘In this study,simple and sensitive spectrophotometric method for the determination of folic acid(VB9)in pharmaceutical formulations was reported.The proposed method was based on the reaction between folic acid and 1,2-naphthoquine-4-sulphonate(NQS)at alkaline medium(pH 11)to form deep yellow product.Beer’s law was obeyed in the range of 0.75-10.5μg/mL of folic acid at maximum wavelength of 436 nm.Under optimized reaction conditions,linear regression equation of the calibration curve was y=0.048 x+0.038(μg/mL)with a linear correlation coefficient of 0.9988.The limit of detection(LOD)and limit of quantification(LOQ)were found to be 0.159μg/mL and 0.531μg/mL,respectively.The method was successfully applied to the determination of folic acid in pharmaceutical formulations.
文摘利用动态差示扫描量热(DSC)实验初步研究了硝基胍的热分解特性,采用Kissinger和Ozawa法计算了其热分解活化能。运用中断回归实验研究了热履历对硝基胍热分解安全性的影响,并用等温DSC实验进行了验证。利用绝热量热仪(ARC)研究了硝基胍的绝热安全性,得到了其初始分解温度,温升速率。结果表明,硝基胍是熔融分解型含能材料,其热分解为自催化反应。热履历显著影响了硝基胍的热分解安全性,降低了其起始分解温度和峰温,使其在固态时就达到较高的热分解速率。在动态DSC实验中,其起始反应温度213.8~249.9℃,峰温215.0~255.2℃,表观活化能为111.6 k J·mol^(-1)和114.2 k J·mol^(-1)。在绝热实验中,其起始反应温度为170.6℃,最大温升速率为1.414℃·min^(-1)。
