Synthesis and analytical application of a novel tetradentate N2O2 Schiff base as a chromogenic reagent for determination of nickel in some natural food samples

A novel sensitive chromogenic reagent, N,N '-bis(3-methylsalicylidene)-ortho-phenylene diamine (MSOPD), has been synthesized and used in the spectrophotometric determination of nickel. At pH 8, MSOPD can react with nickel ion at room temperature to form a 1: 1 complex. The apparent molar absorptivity is 9.5 x 10(4) l mol(-1) cm(-1) at 430 nm. Beer's low is obeyed over the range 0-1.0 x 10(-5) M of nickel with a detection limit of 1.36 x 10(-8) M. The relative standard deviation for measurement of 3.41 x 10(-6) M nickel is 1.3% (n = 10). The method has successfully been applied to determination of trace amounts of nickel in some natural food samples. (c) 2004 Elsevier B.V. All rights reserved.