The use of silica gel modified with allyl 6-methyl-4-phenyl-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carboxylate for selective separation and preconcentration of lead in environmental samples

Abstract

The aim of the present work is the assessment of a new sorbent, prepared using silica gel coated with a pyrimidine derivative (allyl 6-methyl-4-phenyl-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carboxylate), for extraction and preconcentration trace amount of lead from different samples prior to determination by flame atomic absorption spectrometry. Common coexisting ions did not interfere with the separation and determination of lead at pH 6, so that lead ion completely adsorbed on the column. The limit of detection based on three times the standard deviation of the blank was found to be 0.53 ng mL(-1) in original solution. Obtained sorption capacity for 1 g sorbent was 5.0 mg Pb. The linearity was maintained in the concentration range of 0.1-30.0 ng mL(-1) for the concentrated solution. Eight replicate determinations of 2.0 μg mL(-1) of lead in the final solution gave relative standard deviation of ±2.6 %. The proposed method was successfully applied to the determination trace amounts of lead in the environmental samples such as carrot, rice, zardchoobe, and real water samples.

Synthesis of Silica Gel Chelated with Alizarin and 1-Nitroso-2-Naphthol for Solid Phase Extraction of Lead in Ground Water Samples

“…Over the past several years, much interest has been dedicated to the synthesis of selective solid-phase extraction (SPE) sorbents by immobilizing reactive organic compounds (e.g., chelating moieties) onto porous inorganic supports. Perhaps silica gel is one of the most widely used solid support materials because of its well-defined porosity and large surface area [1][2][3]. It also resists swelling and straining, has good mechanical strength, and can withstand thermal treatment.…”