Analytical applications of 2,6-diacetylpyridine bis-4-phenyl-3-thiosemicarbazone and determination of Cu(II) in food samples

New synthesized reagent 2,6-diacetylpyridine bis-4-phenyl-3-thiosemicarbazone (2,6-DAPBPTSC) is proposed as a sensitive and selective analytical reagent for the spectrophotometric determination of copper(II) at pH 3.0 to form a yellowish orange colored 1:1 chelate complex. The maximum absorbance was measured at 370 nm. This method obeys Beer’s law in the concentration range 0.63–6.30 g ml−1 and the correlation coefficient of Cu(II)–2,6-DAPBPTSC complex is 0.942, which indicates an adequate linearity between the two variables with good molar absorptivity and Sandell’s sensitivity, 0.847 × 104 l mol−1 cm−1 and 0.0075 g cm−2, respectively. The instability constant of complex calculated from Asmus′ method is 1.415 × 10−4 at room temperature. The precision and accuracy of the method is checked with calculation of relative standard deviation (n = 5), 0.777% and the detection limit value is 0.0056 g ml−1. The interfering effect of various cations and anions has also been studied. The method was successfully applied for the determination of Cu(II) in food samples. The performance of present method was evaluated in terms of Student ‘t’ test and Variance ‘f’ test, which is indicates the significance of present method is an inter comparison of the experimental values, using atomic absorption spectrometer (AAS).