选择正确的内部参考氧化物种,以克服在电压度 pH 测量中的参考电极漂移
Nafiz B Biswas1, Tania Read1, Katherine J Levey1,2
1Department of Chemistry, University of Warwick, Coventry CV4 7AL, United Kingdom.
概括
这项研究确定了最佳的内部参考物种 (IREF),六化酸盐,以尽量减少pH测量中的参考电极漂移. 这提高了像溶解二氧化碳传感器这样的应用的准确性.
科学领域:
- 电化学 电化学 电化学
- 分析化学 分析化学
- 传感器技术 传感器技术
背景情况:
- 参考电极 (RE) 漂移是长时间pH值测定的一个重大挑战,特别是在复杂矩阵中.
- 伏特度pH测量通常使用内部参考 (IREF) 氧化还原物种,通过测量潜在差异 (E_diff) 来减轻RE漂移.
研究的目的:
- 战略性地探索和识别最适合的IREF物种,用于使用子功能化胺合钻石 (BDD-Q) 电极进行电压学pH测量.
- 为IREF选择建立一个可操作的潜在窗口,考虑峰值分离和水电解潜力.
- 在实际应用中验证所选择的IREF的实用性,例如溶解二氧化碳 (CO2) 传感.
主要方法:
- 使用子功能化的胺合钻石 (BDD-Q) 电极进行pH检测,其pH值范围为4-9.
- 研究了各种IREF候选物,评估了峰值电位的分离和接近水电解电位的距离.
- 采用电压测量来测量溶解的二氧化碳,使用Stow-Severinghaus安排,比较E_diff和E_pH线性.
主要成果:
- 六化酸盐 (IrCl6^2-/3-) 被确定为最佳的IREF,显示最小的pH误差 (pH值比pH值4-9,降至pH值比pH值6-8的0.02).
- 为BDD-Q电极建立了一个可操作的潜在窗口,用于IREF选择.
- 溶解CO2测量的校准图表显示了使用E_diff的优异线性 (R^2 = 0.998),相当于E_pH.
结论:
- 六化是一种高效的IREF,用于减轻BDD-Q电极在电压测量pH测量的RE漂移.
- E_diff测量策略为Stow-Severinghaus系统中溶解CO2传感提供了准确可靠的数据.
- 这种方法对开发强大的,长期的通过皮肤溶解的二氧化碳传感器具有显著的前景.
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