• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>CHROMATOGRAPHY >Determination of Two-Steps Acid Dissociation Constants of L-Ascorbic Acid by Capillary Zone Electrophoresis
【24h】

Determination of Two-Steps Acid Dissociation Constants of L-Ascorbic Acid by Capillary Zone Electrophoresis

机译：毛细管区电泳测定L-抗坏血酸的两步酸解离常数

获取原文
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Two-steps acid dissociation constants of L-ascorbic acid (AA) were determined through the changes in the effective electrophoretic mobility in capillary zone electrophoresis. Although ascorbic acid is oxidatively degradable in an aqueous solution, especially in alkaline conditions, the effective electrophoretic mobility of AA was successfully measured in the pH range between 1.87 and 11.97. In the analysis of the first-step acid dissociation constant (pK _(a1)) at weakly acidic pH conditions, a coated capillary with 1,3-propanesultone and a pressure-assist were utilized to detect anionic AA. In the analysis of the second-step acid dissociation constant (pK _(a2)) at weakly alkaline pH conditions, AA was successfully detected at the pH range up to 11.97 with the help of Cu catalyst to remove the dissolved oxygen in the separation buffer. Acid dissociation constants were independently determined as pK _(a1) = 4.15±0.01 and pK _(a2) = 12.07±0.04 by non-linear least-squares analyses. AA did not fully dissociate at the weakly alkaline pH range, and the effective electrophoretic mobility of the dianion form of AA was extrapolated for the analysis.
机译：通过毛细管区电泳的有效电泳迁移率的变化测定L-抗坏血酸（AA）的两步酸解离常数。虽然抗坏血酸在水溶液中氧化地降解，但特别是在碱性条件下，AA的有效电泳迁移率在1.87和11.97之间的pH范围内成功测量。在弱酸性pH条件下的第一步骤酸解离常数（P K _（A1））的分析中，利用具有1,3-丙酮和压力辅助的涂层毛细管检测阴离子AA。在弱碱性pH条件下的第二步骤酸解离常数（P K _（A2））的分析中，在Cu催化剂的帮助下，在pH范围内成功地检测AA，以除去溶解的氧气在分离缓冲液中。通过非线性最小二乘分析将酸解离常数独立地确定为P k _（A1）= 4.15±0.01和P =（A2）= 12.07±0.04。 AA在弱碱性pH范围内并没有完全解散，并且外推的Dianion形式的AA的有效电泳迁移率为分析。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号