Innovative Instrumentation Section, Real Time Systems Division, Electronics & Instrumentation Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102, Tamil Nadu, India.
Anal Chim Acta. 2010 Jun 11;669(1-2):17-24. doi: 10.1016/j.aca.2010.04.040. Epub 2010 May 14.
A simple but high performance potentiometric titration technique using pulsating sensors has been developed for assay of dissolved oxygen (DO) in water samples down to 10.0 microg L(-1) levels. The technique involves Winkler titration chemistry, commonly used for determination of dissolved oxygen in water at mg L(-1) levels, with modification in methodology for accurate detection of end point even at 10.0 microg L(-1) levels DO present in the sample. An indigenously built sampling cum pretreatment vessel has been deployed for collection and chemical fixing of dissolved oxygen in water samples from flowing water line without exposure to air. A potentiometric titration facility using pulsating sensors developed in-house is used to carry out titration. The power of the titration technique has been realised in estimation of very dilute solution of iodine equivalent to 10 microg L(-1) O(2). Finally, several water samples containing dissolved oxygen from mg L(-1) to microg L(-1) levels were successfully analysed with excellent reproducibility using this new technique. The precision in measurement of DO in water at 10 microg L(-1) O(2) level is 0.14 (n=5), RSD: 1.4%. Probably for the first time a potentiometric titration technique has been successfully deployed for assay of dissolved oxygen in water samples at 10 microg L(-1) levels.
已经开发出一种使用脉动传感器的简单但高性能的电位滴定技术，用于测定水样中的溶解氧（DO），直至 10.0μg L（-1）以下水平。该技术涉及常用于测定水中溶解氧的 Winkler 滴定化学，对其方法学进行了修改，即使在样品中存在 10.0μg L（-1）的 DO 时，也能准确检测终点。已经部署了一个国产的采样和预处理容器，用于收集和化学固定水样中的溶解氧，而无需暴露于空气中。使用国产的脉动传感器的电位滴定设备用于进行滴定。该滴定技术的强大之处在于可以估计碘的非常稀释溶液，相当于 10μg L（-1）的 O（2）。最后，使用这种新技术成功分析了 mg L（-1）至μg L（-1）水平的溶解氧的水样，具有出色的重现性。在 10μg L（-1）的 O（2）水平下测量 DO 的精度为 0.14（n=5），RSD：1.4%。可能首次成功地将电位滴定技术用于测定水样中的溶解氧，达到 10μg L（-1）的水平。
