Optimization of Castor Oil-Based Ion Selective Electrode (ISE) with Active Agent 1,10-Phenanthroline for Aqueous Pb2+ Analysis

Abstract

This research has successfully fabricated ion selective electrode (ISE) for Pb2+ using castor oil (Ricinus communis L.)-based polyurethane (PU) membrane with 1,10‒phenanthroline as the active agent. The sensitivity of the Pb2+ ISE obtained is 27.25 mV/decade with a linear range of [Pb(NO3)2] of 10−10–10−5 M and a coefficient of determination (R2) of 0.959. The system response reaches stability after 25 s of measurement. The Pb2+ has a detection limit of 10−10 M and gives a stable response at pH 7–8 with a 15-day lifetime. The investigation of the selectivity of the ISE was performed using the mixed solution method with log Kij values of <1. The selectivity order of Pb2+ ISE against the foreign ions is Ag2+ > Ca2+ > K+ > Mg2+ > Cu2+ > Fe3+ > Cr3+> Zn2+ > Cd2+. The Pb2+ ISE shows acceptable reproducibility and repeatability with standard deviation values of 0.065 and 0.0079, respectively. Fourier transform infrared (FT-IR) spectra confirmed that 1,10‒phenanthroline was responsible for the formation of the Pb2+ ion entrapment via complexation. Other characterizations (crystallinity, micro-surface morphology, and mechanical strength) suggest the degradation of the membrane structure integrity after the application. The analysis results of Pb levels using the Pb2+ ISE in artificial and wastewater samples were not significantly different from the atomic absorption spectroscopy (AAS) measurement.

Assessment of Al3+ Ion Selectivity Coefficient (Kij) in Polyurethane Membranes Derived from Castor Oil (Ricinus communis. L) via Separated Solution Method

“…The dope solution was prepared using 3.5 grams of commercial castor oil of the Ricinus communis L. mixed with 10 mg of 1,10-phenanthroline in a 50 mL Beaker glass and stirred for 3 hours until homogeneous solution obtained and then reacted with 1.75 grams of TDI followed by heating for 15 minutes at 60 o C. The solution obtained is a clear yellowish dope solution. The same results have also been reported by [11].…”

Ion Selective Electrode (ISE) Method for Determination of Total Fluorine and Total Organic Fluorine in Packaging Substrates

“…Moreover, several studies have shown the use of ISE on the determination of total fluorine on different matrices, such as foams, fuels, lubricants, and organic materials [ 12 , 13 , 14 ]. Additionally, the successful fabrication of ISE from a polyurethane membrane for lead analysis was reported in several research studies [ 15 , 16 , 17 ]. An overview of common analytical techniques for the evaluation of TF/TOF and PFAS [ 18 ] is described in Table 1 .…”