Simple, selective, and sensitive spectrophotometric method for determination of trace a mount of cobalt (II), cadmium (II), lead(II), with a new reagent 1-[(3-methylthiophen-2-yl) methylene]-2-phenylhydrazine

In the present work the substrate phenyl hydrazine reacted with selected 3-methylthiophene-2-carbaldehyde in absolute ethanol and a few drops of glacial acetic acid to give Schiff’s base derivatives as show in Fig. 2. A selective and sensitive reagent of 1-[(3-methylthiophen-2-yl)methylene]-2-phenylhydrazine (MMPH) was synthesized and studied for the spectrophotometric determination of cobalt, cadmium, lead in detail, At a pH value of 9.0, 8.0, 6.0 respectively, which greatly increased the selectivity, Co2+, Cd2+, Pb2+ reacted with (MMPH) to form a 1:2 complexes, with absorption peaks at 404nm for cobalt, 398nm for cadmium and 408 nm for lead. under the optimal conditions, Beers law was obeyed over the ranges of(0.14—5.8, 0.28—11, 0.51—20.72) mg/L respectively. The apparent molar absorptivity and sandell s sensitivities were 59960 ، 52×103 ، 51960 L.mol−1.cm−1 straight, and 9.8287×10−4, 2.16181×10−3, 2.04811×10−3 µg.cm−2, respectively. the detection limits were found to be 1.5461×10−2, 1.982×10−2,4.2229×10−2 µg/ml consecutively.