USING AN INDOL DERIVATIVE AS COMPLEXING AGENT FOR CLOUD POINT PRECONCENTRATION AND DETERMINATION OF MAGNESIUM AND SILVER IONS IN VARIOUS SAMPLES BY FAAS

a very simple cloud point extraction (cpe) methodology for the preconcentration of trace amounts of silver and magnesium as a prior step for their determination by flame atomic absorption spectrometry (faas) has been developed. the method is based on the extraction of silver and magnesium at ph 10 by using non-ionic surfactant triton x-114 and 4 methyl-3-((1-h-indol-3-iyl) (phenyl) methyl)) -1-h-indol (mpbim) as a complexing agent. several important variables that affect the cpe efficiency and faas signal were investigated and optimized. the calibration curves, using the preconcentration system, were linear in the range of 0.007-0.200 μg ml-1 with a correlation coefficient of 0.999. the lower limits of detection (3s) obtained in the optimal conditions were 1.47 ng ml-1 and 3.00 ng ml-1 for mg2+ and ag+ ions, respectively. the relative standard deviation for five replicate determinations of magnesium and silver at 0.133 μg ml-1 concentration level, were 1.17 and 0.97, respectively. the proposed method was successfully applied to the ultra-trace determination of silver and magnesium in various water samples, blood serum, urine, and radiology film samples.