DEVELOPMENT OF AN AUTOMATIC TITRATION SYSTEM FOR DETERMINATION OF Ca and Mg MACRO PLANT NUTRIENTS IN THE SOIL
Project Funding : TAGEM (% 100) – General Directorate of Agricultural Research amd Policies
Project No: TAGEM-15/AR-GE/68
Duration: 24 months – 15.07.2015 – 15.07.2017
Macro (N, P, S, K, Ca, Mg) and micro (Fe, Zn, Mn, Cu, W, Mo) plant nutrients are essential elements that plants must have in order to grow properly. In their absence the plant is unable to complete a normal life cycle; therefore the quality and yield of the product decrease significantly. In case of Ca and Mg, determination of these elements is extremely important both for the need of a balanced fertilization advice and for a good product. There are two main methods used for the determination of Ca and Mg elements:
1) Standard method : Manual titration by using EDTA in the laboratory
2) Spectroscopic devices : Inductively coupled plasma atomic emission spectroscopy (ICP-OES) and Atomic Absorption Spectroscopy (AAS)
Despite their frequency of usage, the first method is manual therefore has some disadvantages depending on the person doing the analysis while the second one is quite expensive due to the properties of the device. In this project, an automated titration system for the determination of Ca and Mg nutrients will be developped. As an alternative to the manual titration, this method will have considerable superiorities such as ease of use, labor and time saving. On the other hand comparing to the spectroscopic devices, our system will be portable and cheaper. In this context, the most important innovation in the project is using a camera in order to see and save the turning point (change of colour) during titration. In the manuel method, the person doing the anaysis see it and stop the experiment while in other automated systems ion selective electrodes (ISE) are used. The lifetime of these electrodes are usually 2-3 months while the camera in our system can be used for 2-3 years and the cost of the device reduces significantly.
Thus in the new system, sample prepreparation, adding titrant and indicator within the determination of color turning point will be automatic. Except for certain processes, this device will be working independently from the human factor while performing 24 (12 Ca-Mg and 12 Ca) analysis at the same time. The time for each experiment will be shortened by automatical injection of the water, indicator, buffer simultenously and slow EDTA addition into the sample by using multichannel pumps during titration.