Gros Natasa
Faculty of Chemistry and Chemical Technology, University of Ljubljana, Askerceva 5, SI-1000 Ljubljana, Slovenia.
Talanta. 2005 Feb 28;65(4):907-12. doi: 10.1016/j.talanta.2004.08.025.
A spectrometric microtitrator was developed from a spectrometer with a microreaction chamber and a tri-colour light-emitting diode (LED) as the light source. A novel, vertical, optical geometry of the spectrometric microtitration chamber was introduced and tested. This novel geometry also required a new method for mixing the titrated solution. A laboratory-made 50mul syringe pump was used for the addition of the titration reagent. The 10-channel module for light effects, which makes possible a low-cost hardware approach to changing the titration protocols, was used for coordinating the operation of the microtitration set up. The system, with 10 channels and a regulated speed of operation, is flexible enough to allow an operator to generate different titration protocols. The performance test showed that the speed of titration-reagent addition can be regulated in the range from 0.87 to 21.8mulmin(-1). The smallest achievable volume addition is equal to 35nl. The mixing rate can be continuously regulated by an electrical pulse that initiates the mixing cycle. The quickest rate is every 1.6s, and the slowest rate is every 4.8s. The spectrometric microtitration set up was successfully tested for several different real-life spectrometric titrations, including an iodometric titration, a determination of CO(2) in deionised water, and EDTA titrations of copper(II) ions with no indicator. The volume of the examined solution can be as small as 220mul. The titration-reagent consumption is usually between 10 and 35mul. Coefficients of variation of the end point volume determination (n = 5) at different experimental conditions and different average volumes of consumed reagents (7.06, 12.17 and 22.88mul) were 2.4, 1.3 and 1.2%, respectively. The novel geometry of the spectrometric microtitration chamber proved to be useful for real-life applications.
一种光谱微量滴定仪由一台带有微反应室的光谱仪和一个三色发光二极管（LED）作为光源制成。引入并测试了一种新型的、垂直的光谱微量滴定室光学几何结构。这种新型几何结构还需要一种混合滴定溶液的新方法。使用实验室自制的50微升注射泵添加滴定剂。用于光效应的10通道模块用于协调微量滴定装置的操作，它使低成本硬件方法改变滴定方案成为可能。该系统有10个通道且操作速度可调，足够灵活，允许操作员生成不同的滴定方案。性能测试表明，滴定剂添加速度可在0.87至21.8微升/分钟（-1）范围内调节。可实现的最小添加体积等于35纳升。混合速率可通过启动混合循环的电脉冲连续调节。最快速率为每1.6秒一次，最慢速率为每4.8秒一次。该光谱微量滴定装置已成功用于几种不同的实际光谱滴定测试，包括碘量滴定、去离子水中二氧化碳的测定以及无指示剂时铜（II）离子的EDTA滴定。被检测溶液的体积可小至220微升。滴定剂消耗量通常在10至35微升之间。在不同实验条件和不同平均消耗试剂体积（7.06、12.17和22.88微升）下，终点体积测定的变异系数（n = 5）分别为2.4%、1.3%和1.2%。光谱微量滴定室的新型几何结构被证明对实际应用有用。
