MODIFIED PERLITE WITH 1, 6-DIAMINO-4-(4-CHLORNPHENYL)-2-OXO-1, 2-DIHYDROPYRIDINE-3, 5-DICARBONITRILE FOR SELECTIVE EXTRACTION OF TRACE AMOUNTS OF SILVER FROM WATER SAMPLES

In the present work, a solid phase extraction procedure was proposed for separation and preconcentration trace amounts of silver ion using perlite coated with 1,6-diamino-4-(4-chlornphenyl)-2-oxo-1,2-dihydropyridine-3,5-dicarbonitrile [DCODD] prior to its determination by flame atomic absorption spectrometry. Analytical parameters including pH of sample solution, sample volume, flow rate of sample solution, volume and concentration of eluent were studied and optimized. Under the best experimental conditions, it was found that extraction can be performed from the sample volume of 500 for silver ion (preconcentration factor of 100). The obtained sorption capacity for 1 g sorbent was 10 mg silver. Linearity was maintained between 0.006–1.5 μg mL−1 for silver. Detection limit for silver based on 3Sb was 1.6 ng mL−1. The relative standard deviation of eight replicate measurement of 0.2 μg mL−1of silver was 2.1%. Finally, the developed method was successfully applied to extraction and determination of the silver ions in the water and standard samples and satisfactory results were obtained.

Keywords:

Solid phase extraction , Silver determination , Preconcentration , Modified perlite , Flame atomic absorption spectroscopy