Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand; Center of Excellence for Innovation in Analytical Science and Technology, Chiang Mai University, Chiang Mai 50200, Thailand.
Talanta. 2013 Oct 15;115:258-62. doi: 10.1016/j.talanta.2013.04.039. Epub 2013 May 3.
Miniaturized coulometric titration in a liquid drop has been investigated. Assays of ascorbic acid and thiosulfate with iodine titration were chosen as models. Constant volumes of falling liquid drops containing sample or reagent are manipulated via gravimetrical force to move along a slope hydrophobic path and directed to stop or to move out from an electrode. Such manipulation is useful for delivery of sample and reagents, in a way of flow without tubing. Electrochemical generation of titrant, in this case, iodine, is started at the electrode and micro coulometric titration can be performed in a drop by applying constant current. Timing in the titration can be made via naked eye with a stopwatch or via recording with a webcam camera connecting to a computer to detect the change due to the blue color complex of the excess iodine and starch.
已研究了在液滴中的微型库仑滴定。选择碘滴定法测定抗坏血酸和硫代硫酸盐的分析作为模型。通过重力操纵含有样品或试剂的恒体积下落液滴沿着疏水斜坡移动，并引导其停止或从电极处移出。这种操作对于输送样品和试剂非常有用，不需要使用管道进行流动。在这种情况下，通过在电极处开始电化学生成滴定剂（例如碘），并通过施加恒电流，可以在液滴中进行微库仑滴定。通过使用秒表进行肉眼计时或通过使用连接到计算机的网络摄像头进行记录以检测由于过量碘和淀粉的蓝色络合物而引起的变化，可以进行滴定定时。
