التقدير الطيفي بالحقن الجرياني للنحاس الثنائي والنيكل الثنائي باستخدام كـاشــف عضوي جــديد N”-[(3-methylthiophen-2-yl) thiocarbonohydrazide methylidene]

Flow injection Spectrophotometric Determination of Copper (II) and Nickel (II) Using a New Organic Reagent N''-[(3-Methylthiophen-2-yl) Methylidene] Thiocarbonohydrazide

this study included the use of two analytical techniques to determine copper and nickel (II). The first method is sensitive and accurate using the microspectral analysis technique, and the second method is more sensitive and accurate, which is flow injection analysis. A reagent (Schiff base) was prepared and characterized to estimate small amounts of heavy metal ions, nickel (II) and copper (II) by forming colored complexes with them. The reagent was characterized by ultraviolet-visible (UV-Vis) and infrared (FT-IR) spectra, as well as the proton nuclear magnetic resonance (1H-NMR) spectrum, while the complexes were characterized by ultraviolet-visible (UV-Vis) spectra.
Some physical properties of the complexes were also studied, such as solubility, melting point, and electrical conductivity. The best conditions for the formation of complexes were also determined, such as the effect of the acid function, the effect of the concentration of the reagent solution, and the effect of the time period for the stability of the complexes formed after 24 hours, which were almost constant, which proves that the complexes prepared under study have high stability.
The range of linear concentrations that obeyed the Beer-Lambert law was determined by calibration curves, which were within the range of (1-14) ppm for the nickel (II) complex, (0.1-11) ppm for the copper (II) complex by the spectrophotometric method, and (0.1-12) ppm for the copper (II) complex,( 0.5-9) for the nickel (II) complex by the flow injection method. From this, the molar absorption coefficient, Sandell’s sensitivity, and the correlation coefficient were determined for both methods.
The valency of the prepared complexes was also studied to find the ratio of the metal ion to the reagent using the molar ratio method. The results showed that the ratio was (1:1) (metal: reagent) for all complexes. The charge of the dissolved complexes was determined using the electrical conductivity device. The result was that the coordination sphere for nickel is uncharged and for copper is charged. From all of the above, the octahedral geometric shape was proposed for the complexes under study. The Precision, accuracy and sensitivity of the spectral analytical method and flow injection used were determined using standard solutions of selected ions with standard solutions of the detector at three different concentrations. From this, the standard deviation and the relative standard deviation (%) were calculated, the limits of which did not exceed(1.000%), the relative error (%) were calculated, the limits of which did not exceed (±1.000), and the recovery ratio was calculated. From this, we conclude that the used spectral methods have good accuracy, Precision and sensitivity. By means of the above results, we conclude that the proposed methods are fast, economical, environmentally friendly, easy to apply, with good accuracy, sensitivity and high selectivity