Synthesis and analytical application of a novel tetradentate N(2)O(2) 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 9.5x10(4)lmol(-1)cm(-1) at 430nm. Beer's low is obeyed over the range 0-1.0x10(-5)M of nickel with a detection limit of 1.36x10(-8)M. The relative standard deviation for measurement of 3.41x10(-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.