تحضير وتشخيص مشتقات الداي ثايو كاربامات الجديدة واستخدامها في التقدير الطيفي لكميات ضئيلة للأيونات الفلزية

Preparation and Characterization of New Dithiocarbamate Derivatives and Using them for Spectrophotometric Determination of Micro Amounts of Metal ions

abstract

The first part of this work includes preparation new three reagents, N-methyl-N-((((4-nitrophenyl)diazenyl)thio)carbonothioyl) aniline [R1], N-methyl-N-((((4-chlorophenyl)diazenyl)thio)carbonothioyl) aniline [R2], and N-methyl-N-((((4-bromophenyl)diazenyl)thio)carbonothioyl)aniline [R3]. The new reagents were prepared by the reaction of diazonium salts with a compound (sodium N-methyl-N-phenyl dithiocarbamate). They were characterized by elemental analysis technique, infrared spectroscopy, proton nuclear magnetic resonace spectroscopy, 13C nuclear magnetic resonace spectroscopy, mass spectroscopy, and ultraviolet-visible spectroscopy that were used to identify the structures compounds. Fe(II) and Zn(II) ions complexes with reagent (R1), Mn(II) and Fe(II) ions complexes with reagent (R2), and Cr(II) and Cd(II) ions complexes with reagent(R3) were prepared and characterized by the previous techniques and additional electrical molar conductivity, and magnetic susceptibility measurements. Stoichiometry can be determined by using analytical and spectroscopic information. It was found to be [1:2] metal to a reagent for every complexes. The spectral data confirm the good coordination of the dithiocarbamate reagent with the metal through sulfur atoms of the dithiocarbamate moiety. The molar conductivity of complexes were measured using dimethyl formide as a solvent. This indicated that the complexes of Fe(II), Zn(II), Mn(II), Cr(III), and Cd(II) were ionic. According to the results of spectroscopic measurements and elemental analyses, the tetrahedral shape of the prepared complexes was proposed.
The second part tackles, cloud point extraction which was developed for the preconcentration and separation of Fe(II) and Zn(II) with reagent(R1), Mn(II) and Fe(II) with reagent(R2), and Cr(II) and Cd(II) with reagent(R3) in drug samples. ultraviolet-visible absorption and flame atomic absorption were used to measure at λmax (494 and 484 nm), (436 and 635 nm), and (536 and 525 nm), respectively. The main factors such as pH, concentrations of reagent and Triton X-114, type of surfactant, salt out effect, interference effect, equilibrium temperature, and time that affect the efficiency of cloud point extraction are optimized. The calibration curve of (Fe(II) and Zn(II) with R1), (Mn(II) and Fe(II) with R2) and (Cr(III) and Cd(II) with R3) were identified in the extent from (1-15 mg L-1 and 0.6 -10 mg L-1), (0.1-1 mg L-1 and 0.2-1 μg. mL-1), and (0.3 – 2 mg L-1 and 0.1 – 1 mg L-1), respectively. The values of R2 were found to be (0.9877 and 0.9905), (0.9860 and 0.9962),and (0.9888 and 0.9907) for (Fe(II) and Zn(II) with R1), (Mn(II) and Fe(II) with R2) and (Cr(III) and Cd(II) with R3), respectively. The detection limit was (0.9273, 0.0975, 0.1164, 0.0504, 0.0397, and 0.0296 mg L-1) and the quantification limit was ( 2.8102, 0.2956, 0.3529, 0.1530, 0.1205, and 0.0899 mg L-1 ) separately. This method was also compared with one of the standard methods, which is fame atomic absorption spectroscopy for estimating both drugs. Through the results obtained which are based on statistical tests (paired t-test, known t-test and f-test), it is shown that the new method can be used as an alternative method.