Development of Extracting Solution for Soil Chemical Analysis Suitable to Integrated Ion-selective Micro-electrodes
2009
Shiin, K.S., Hankyong National University, Ansung, Republic of Korea | Lim, W.J., Hankyong National University, Ansung, Republic of Korea | Lee, S.E., Hankyong National University, Ansung, Republic of Korea | Lee, J.S., Kwangwoon University, Seoul, Republic of Korea | Cha, G.S., Kwangwoon University, Seoul, Republic of Korea
The primary goal of this research was to develop an optimized analytical procedure for soil analysis based on ion-selective microelectrodes for agricultural purposes, which can perform on-site measurement of various ions in soil easily and rapidly. For the simple and rapid on-site diagnosis, an analysis of soil chemicals was performed employing a multicomponent-in-situ-extractant and an evaluation of ionselective microelectrodes were conducted through the regressive correlation method with a standard analytical approach widely employed in this area. Examination of sensor responses between various soil nutrient extractants revealed that 0.01M HCl and 1M LiCl provided the most ideal Nernstian response. However, 1M LiCl deteriorated the selective response for analytes due to high concentration (1M) of lithium cation. Thus, employing either 0.1M HCl as an extractant followed by 10 times dilution, or 0.01M HCl as an extractant without further dilution was chosen as the optimal extractant composition. A study of regressive correlation between results from ion-selective microelectrodes and those from the standard analytical procedure showed that analyses of K+, Na+, Ca²+, and NO₃- showed the excellent consistency between two methods. However, the response for NH₄+ suffered the severe interference from K+. In addition, the selectivity for Mg²+ over Ca²+ was not sufficient enough since available ionophores developed so far do not provide such a high selectivity for Mg²+. Therefore, as an agricultural on-site diagnostic instrument, the device in development requires further research on NH₄+ analysis in the soil sample, development of Mg²+-selective ionophore, and more detailed study focused on potassium, one of the most important plant nutrients.
显示更多 [+] 显示较少 [-]