Paper Title
A New Nitrate-Selective Electrode Based on Bis-Thiourea Xanthene Spacer Derivative

Abstract
A new nitrate selective electrode has been developed. This electrode uses a derivative of bis-thiourea as ionophore. Bis-thiourea derivatives obtained from the reaction between bis (aminomethyl) benzene with nitrophenylisothiocyanate. Nitrate selective electrode showed near Nerstian values -54.7 3.5mV/dec with RSD value is 6.5% . Meanwhile, the linear range is 0.1 M - 10-5 M and the sensor has a detection limit is 4.1 x 10-6 M. In this study, Log Kpota,b values are given for each interference ion is Cl- -1.36 0.12, HPO42- -2.80 0.24, Br- -0.58 0.10, CrO42- -1.32 0.21, SO42- -2.42 0.31. Artificial samples, fish pond and soil used as real samples. Nitrate sensors give a similar results with commercial sensor. Keywords- Nitrate-selective electrode, Bis (aminomethyl) benzene, Nitrophenylisothiocyanate, Bis-thiourea.