التقدير الطيفي لأيوني Co(II) و Cr(III) بأستخدام مشتق قاعدة شف الجديد

Spectrophotometric Determination of Co(II) and Cr(III) ions Using a New Schiff Base Derivetives

ABSTRACT

This study dealt with the preparation of a Schiff base reagent from condensation method from (8-aminoquinoline) with 4,4′-dimethoxybenzil to create reagent (BMPQYE1).The reagent was characterized by spectrophotometry techniques such as FT-IR, ultraviolet,1HNMR and 13CNMR, mass spectrometry.and conducting. A preliminary test was done for a number of 11 elements, and the Cobalt and Chromium ions were chosen to form complexes with the reagent. The maximum absorption of the reagent dissolved in ethanol was (λmax = 467 nm). Additionally, the best conditions for the reaction were studied, such as the pH function, the effect of time, temperature, volume of the reagent, and the effect of addition, and the calibration curves for both complexes were shown, which it was obyed the Beer’s law in the range of the Cobalt(II) and Chromium(III) complexs with the concentration range (1-12)μg/5mL,(1 -8)μg/10mL with the linearity coefficient(R2=0.9998), (R2 = 0.9999) sequentially and the absorbance value.The molar absorptivity (ε)of cobalt was equal to(2.9×103 L. moL-1.cm-1) and Sandal’s sensitivity was equal to (0.102μg/cm2),value of the Chromium molar absorptivity (ε) was equal (1.1×104 L.moL-1.cm-1) ,Sandal’s sensitivity equal (0.25μg/cm2) . Using the Job method and the mole ratio method for the Cobalt (II) and Chromium (III) complexes, the ion-to-reagent ratio (M:L) was determined. The stability constant (Ksta) for the cobalt (II) and chromium (III) complexes were (Ksta = 3.749 × 108). and (Ksta = 3.332 × 1010), respectively. Also, the thermodynamic functions (ΔH, ΔG and ΔS) were calculated, as it was shown through the results that the reaction of the formation of the Cobalt (II) complex was endothermic and that the Chromium (III) complex was exothermic .The study demonstrated interference of the presence of a number of cations
and anions as potential interactions when estimating the Cobalt(II) and Chromium(III) ions and the addition of appropriate masking agents was studied, as it was found that these ions interact to varying degrees depending on the nature and concentration of the interfering ion, and some of them did not show any effect.By measuring the conductivity, the charge of the two complexes was determined, where the Cobalt complex was uncharged and the Chromium complex was charged. The accuracy and precision of the analytical method were determined using five different concentrations. Relative Standard Deviation (RSD%) for the cobalt(II) ion ranged between (0.598%-1.567%) and the relative recovery ranged between (98.49% -101.19%), the values of the relative standard deviation (RSD%) for the Chromium(III) ion values ranged between (0.661% – 0.887%) and the relative recovery ranging between (99.98% – 101.16%), through which the detection limit was found for the Cobalt(II) and Chromium(III)ions(0.449μg/5mL),(0.769μg/10mL), respectively,which shows the sensitivity of the spectral technique using this ligand (BMPQYE1).Determining physical properties such as solubility ,melting point, and molar conductivity, the sedimentation of the reagent and the two complexes have also been investigated. The method was used to determine the amounts of Cobalt(II) and Chromium(III) ions in the pharmaceutical and hair sample. The method found a high in sensitivity and accuracy.