March 8, 2010
School of Arts and Sciences, Amritapuri
Few people may have perhaps heard of neodymium, a rare earth metal. The most abundant of all rare earth metals, neodymium is used extensively in the automotive industry in the fabrication of starter motors, brake systems, seat adjusters and car stereo speakers.
Now a new electrochemical sensor fabricated at Amrita for trace-level determination of neodymium ions in solution is receiving much attention. This new sensor is cost effective and simple to operate.
“The conventional methods for determination of neodymium ions are spectrophotometry, X-ray fluorescence (AAS), neutron activation analysis, isotopic dilution method and inductively coupled plasma atomic emission spectroscopy (ICP AES),” explained Ms. Beena S. of the Amrita School of Arts and Sciences, who led the study.
“But these methods require preparation of multiple samples and also infrastructure backup and are not so convenient,” she added. “Our work involves the fabrication of a PVC membrane type ion selective electrode. Ion selective electrodes (ISE) are potentiometric electrochemical sensors.”
Ms. Beena presented her work as a paper titled New PVC Membrane Sensor For Neodymium (III) Based on N1, N2 Bis (Salicylidine) Butane-1, 4-Diamine at the 15th National Convention of Electrochemists, recently concluded at VIT, Vellore. The paper received the best paper award at the conference.
“This work details fabrication of a PVC membrane sensor impregnated with N1, N2-bis (salicylidine) butane-1,4-diamine as ionophore for the determination of neodymium,” the paper abstract stated. “The optimized membrane composition that gave the best response in terms of slope, concentration range and response was found to be 3:32:62:3 (SAB: PVC: plasticizer: NaTBP ) (w/w %).”
“The sensor showed nernstian response over a wide concentration range of 1×10-6 to 1×10-2 M with a slope of 20.6mv/decade. Detection limit was found to be 8.7×10-7 M. The response time of the sensor is < 15s and shelf life was found to be 7 weeks. It was found that in the pH range 3.1-7.5, the response behavior of the sensor was independent of pH.”
“The electrode showed good selectivity for Nd (III) ion with respect to most common cations, including alkali, alkaline earth, transition, and other lanthanide ions. The newly developed sensor was employed as an indication electrode in the potentiometric titration of neodymium with EDTA and also applied in the direct monitoring of neodymium from binary mixtures.”