Determination of 2,4-dinitrophenylhydrazine using carbon paste modified with nanoparticles by cyclic voltammetry, high-performance liquid chromatography and spectrophotometry methods

The research deals with the manufacture of an electrode using modified carbon paste to determine 2,4-dinitrophenylhydrazine (2,4-DNPHZ), The modified carbon paste electrode (NiO-NCQD/g-C3N4/MCPE). The results show the presence of oxidation and reduction peaks, and it is subject to a quasi-reversible system; the best value ​​of pH is (1) using sulfuric acid with a concentration of (0.1M), and scan rate is 100 mv sec-1, it was linearity range of (1-1000) µM for oxidation, and (100-1000) µM for reduction, with correlation coefficient (R2=0.9717) and (R2=0.9914) for each of them, respectively. The proposed electrochemical method was compared with two methods they are spectrophotometry at a wavelength 360) nm( and high-performance liquid chromatography (HPLC) at wavelengths (340 and 250) nm. It turned out that the electrochemical method (NiO-NCQD/g-C3N4/MCPE) was superior to the spectrophotometry method in terms of the detection limit. It turns out that there is no significant difference between (HPLC) and (NiO-NCQD/g-C3N4/MCPE) in terms of accuracy. The proposed electrochemical method is a new analytical method characterized by accuracy, repeatability, and reliability.