American Journal of Analytical Chemistry, 2011, 2, 626-631 doi:10.4236/ajac.2011.25071 Published Online September 2011 (http://www.SciRP.org/journal/ajac) Copyright © 2011 SciRes. AJAC Preconcentration of Lead in Sugar Samples by Solid Phase Extraction and Its Determination by Flame Atomic Absorption Spectrometry Saied Saeed Hosseiny Davarani 1,* , Neda Sheijooni-Fumani 2 , Amin Morteza Najarian 1 , Mohammad-Ali Tabatabaei 1 , Siavash Vahidi 1 1 Department of Chemistry, Faculty of Science, Shahid Beheshti University, GC, Tehran, Iran 2 Department of Marine Living Resources, Iranian National Institute for Oceanography, Tehran, Iran E-mail: ss-hosseiny@cc.sbu.ac.ir Received May 21, 2011; revised June 27, 2011; accepted July 4, 2011 Abstract A simple and sensitive solid phase extraction utilizing C18 filled cartridges incorporated with dithizone for preconcentration of lead and its subsequent determination by flame atomic absorption spectrometry (FAAS) was developed. Several parameters such as type, concentration and volume of eluent, pH of the sample solu- tion, flow rate of extraction and volume of the sample were evaluated. The effect of a variety of ions on preconcentration and recovery was also investigated. At pH = 7.4 and 1.0 mol·L –1 HCl eluting them, lead ions were recovered quantitatively. The limit of detection (LOD) defined as 3S bl was determined to be 8.1 μg L –1 for 500 mL of sample solution and eluted with 5 mL of 1.0 mol·L –1 HCl under optimum conditions. The accuracy and precision (RSD %) of the method were >90% and <10%, respectively. In the end, the proposed method was applied to a number of real sugar samples and the amount of lead was determined by spiking a known concentration of lead into the solution. Keywords: Solid Phase Extraction, Lead, Dithizone, Flame Atomic Absorption Spectroscopy (FAAS), C18 Modified Cartridges 1. Introduction In the past several years, environmental pollution caused by contamination by an assortment of heavy metal ions has become a global problem. Of the heavy metals most harmful for human is lead. Exposure to excessive am- ounts of lead may cause irreversible neurological damage as well as renal disease and cardiovascular effects [1]. On the top of that, the aforementioned pollutions have found their way in the food-chain and have greater en- dangered public health [2]. Hence, accurate and sensitive determination of lead in food samples is of prime impor- tance. Various methods and techniques are utilized for de- termination of heavy metals in food samples. It is most often done by ICP-OES, ICP-MS, GFAAS and FAAS [3]. Due to its low cost and simplicity, the most com- monly used technique for determination of metals in various samples is FAAS. However, FAAS has its own limitations and is particularly circumscribed by its char- acteristic low sensitivity [4-8]. Preconcentration tech- niques play a pivotal role should FAAS is to be utilized as it improves analytical detection limit, increases sensi- tivity by several orders of magnitude and enhances ac- curacy of results [9-10]. Recently a great deal of work has been devoted to solid phase extraction (SPE) as a preconcentration tech- nique. It offers advantages such as short extraction time, low cost, high enrichment factors and recoveries and low consumption of non environment-friendly solvents. SPE can easily be used in tandem with FAAS without much trouble and is generally considered to be a simple method [2,11-16]. Currently, the most common and widely accepted method for determination of lead in sugar samples is ICUMSA’s, which is based upon a colorimetric proce- dure and is suitable for white and raw sugar, as well as low-grade products with lead contents not exceeding 0.5 mg Pb/Kg. Although widely accepted and utilized in analysis laboratories, the method involves consumption