O M I C S P u blishin g G r o u p J Chem Eng Process Technol ISSN: 2157-7048 JCEPT, an open access journal Journal of Chemical Engineering & Process Technology - Open Access www.omicsonline.org Research Article OPEN ACCESS Freely available online doi:10.4172/2157-7048.1000102 Volume 1• Issue 1•1000102 Synthesis of Schiff Base Unsaturated Oligomeric Polyester for Determination of Trace Lead Samy K. Badr * and Alaa S. Amin Chemistry Department, Faculty of Science, Benha University, Benha, Egypt Keywords: Unsaturated polyester; Spectrophotometry; Lead determination; Clinical analysis Introduction It is well known that absorbed superfluous lead is vital to human, but people would also sicken serious diseases such as encephalopathy, kidney damage, and memory loss even if exposure a small quantity of it due to its cumulative characteristic in organism and bones [1,4]. Lead and its compounds are hazardous, lead poisoning was cumulative and its toxic effects are many and severe [5,6]. Because of environmental pollution (especially in developing countries), clinical lead analysis is becoming increasingly important. Analysis of clinical samples must be reliable, are simple and quick as possible. Flame atomic absorption spectrometry (FAAS), electro- thermal atomic absorption spectrometry (ETAAS), flow injection (FI) [7-10], and electrochemical sensor [11-13] were used for the analysis of lead. However, FAAS was reliable down to about 0.2μg L −1 and so was not always suitable for the analysis of lead in clinical samples ETAAS and FI are generally used to determine lead at low concentrations, but they were complex to use; moreover, some type of preconcentration or extraction step must be used to meet the requirement of accuracy and precision. Spectrophotometric methods were versatile and economical. Dithiazone [14], diethyldithiocarbamate [15-17], arsenazo III [14], 4-(2-pyridylazo)-resorcinol (PAR) [18], malachite green [19], butylrhodamine-B [20], xylenol orange [21], 2-(2-thiazolylazo)-p- cresol, dithiodibenzoic acid [22], dithiodibenzoic acid iodide– ethylene violet- polyvinyl chloride [23], and a copolymer consisting of protoporphyrin disodium salt and acrylamide [24] were suitable for the trace analysis of lead in clinical samples due to their low detection limit. Dibromo-p-methylsulfonazo [25] was sensitive, but Ca 2+ and Mg 2+ , which exist in clinical samples were reasonable amounts, interfere with the determination of lead and require prior separation with potassium iodide-methylisobutylketone extraction. Polymers having the amino acid moiety in the main chain or in the side chain find a variety of useful applications, such as chelating agents for metal ions, ion-exchange resins, polymer catalysts with enzyme like behavior, and promotes for preparing polymeric carrier’s *Corresponding author: Samy K. Badr, Chemistry Department, Faculty of Science, Benha University, Benha, Egypt, E-mail: drsamykh@yahoo.com Received August 30, 2010; Accepted October 04, 2010; Published October 06, 2010 Citation: Badr SK, Amin AS (2010) Synthesis of Schiff Base Unsaturated Oligomeric Polyester for Determination of Trace Lead. J Chem Eng Process Technol 1:102. doi:10.4172/2157-7048.1000102 Copyright: © 2010 Badr SK, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Abstract A new very sensitive and selective chromogenic reagents prepared by the reaction of Schiff base with maleic anhydride (MA) and 1,4-butane (I), ethylene (II), 1,6-hexamethylene (III) and 1,2-propane diol (IV), respectively, were synthesized and studied for the determination of trace lead in detail. In 0.1molL −1 NaOH medium, lead reacts with polyester to form a yellow complex, which gives a maximum absorption at 462, 478, 482 and 495 nm using I, II, III and IV respectively. Beer’s law is obeyed over the concentration ranges 0.04-1.20μgmL −1 , whereas optimum concentration ranges as adopted from Ringbom method was 0.10-1.05μgmL −1 . The molar absorptivity, Sandell sensitivity, detection and quantification limits are also calculated Ca (3500-fold), Mg (2250-fold), Sr (1250-fold), Ba (1000-fold), Al (1500-fold), Bi (800-fold), Fe (2500-fold) Co (1100-fold), Ni (1000-fold), Cu (900-fold), Zn (1300-fold), Cd (2500-fold), and Ag (750- fold) do not interfere with the determination of lead. The chromogenic system is remarkably superior to other reagents, especially porphyrin compounds. The influence caused by oxygen in air or in solution can be easily eliminated by adding Na 2 SO 3 . The reaction is very stable, the stability constant of the complex being 1.44 x 10 45 . The chromogenic reaction is completed within 2.0 min at room temperature. The proposed method has been applied to the direct determination of trace lead in clinical samples. The accuracy and precision are both very satisfactory. drugs [26–31] polyesters with pendant amino groups and carbonyl oxygen of the ester group as donor sites per unit may yield metal- coordinated polymers with interesting properties. However, few investigations had been reported on the synthesis of polyesters having amino acid moieties in the main chain. Earlier, reported the synthesis and characterization of poly (ethyleneaspirate)-metal complexes [32] which were found to be thermally more stable than the polyesters itself. The present investigation aimed to synthesize polyester based on Schiff base derived from amino acid have attached much attention as analytical regents owing to their very high sensitivity, however, certain problems seriously effect their application, such as solubility and selectivity (especially transition metal ions interfere with the determination of lead). All foreign ions studied in reasonable amounts do not interfere with the determination of trace lead. The proposed method has been applied to the direct determination of lead in clinical samples with good precision and accuracy. The method is one of the most sensitive and efficient techniques for the determination of trace lead at the present time. Experimental Materials DL aspartic acid (Aldrich Comp), salicylaldhyde (WIN LAB, U.K.)