Abstract
A novel ion-selective chemically modified carbon paste sensor (CMCPs) for Cr(III) ions based on N-[4-(dimethylamino)benzylidene]-6-nitro-1,3-benzothiazol-2-amine (DMBNA) as a new ionophore was prepared and optimized. The best performance was observed for the paste composition, including 50: 37.5: 12.5 (wt%) graphite: TCP: DMBNA. The electrode showed a good Nernstian slope of 19.9 +/- 0.2 mVdecade(-1) in a concentration range from 1.0x10(-6) to 1.0x10(-1) mol L-1 Cr(III) with detection limit of 2.8x10(-7) mol L-1. The fabricated sensor exhibited a fast response time (9 s) and could be used for about 16 weeks in the pH range of 2.0-7.0. The electrode showed good selectivity for Cr(III) ion towards wide variety of metal ions. The proposed sensor was applied for the determination of Cr(III) ion in different real water samples. The results obtained were compared well with those obtained using inductively coupled plasma atomic absorption spectrometry (ICP-AES).