Synthesis of the rhodamine derivative dyes, determination of some heavy metal using fluorimetric method in the food and environmental samples

In this study,some dyes compound containing xanthan ring, which were named Rhodamine B, Rhodamine 6G and Fluorescein were converted the hydrazides to use the condensation reaction according to the literature. The reactions that some aldehyde groups containing of the reagents with the dye compounds increasing nucleophilic property were performed. IR, 1H-NMR, 13C-NMR and elemental analysis were characterized. The synthesized 3',6'-bis(diethylamino)-2-{[(1E)-(2,4-dimethoxyphenyll)methylene]amino}spiro-[isoindol-1,9'-xanthan]-3(2H)-one (BDAS) reagents were used as ligands and the complex formation with the metal ions were examined using fluorescence spectroscopy. The BDAS reagent was formed complex compound with only Cr(III) as selective and had increased fluorescence property of the reagent. In the same way, Cr(VI) was usedto form complex compound with the BDAS reagent, but were not form any fluoresence signal.Due to the different effect of the chromium, environmental and food samples speciation of chromium is also very important. Speciation ofchromium was performed without the use of any preconcentrationmethod. For the optimization of the method, sample pH and acidity, the amount of BDAS, the amount of Cr(III), the amount of temperature, the waiting time for the complex formation of Cr(III)-BDAS, the effect of the amount of HA•HCl, the effect of reduction time for the complex formation, the effect of the surfactant were performed for ultra-trace quantities of Cr(III) determination in some food and environmental samples. The accuracy of the developed method was verifiedusing CWW-TMD wastewater,INCT-TL-1 standard reference materials. Keywords: Chromium, Speciation, Molecular fluorescence, Rhodamine, Food and Environmental Samples.