Determination of Lead Employing Simple Flow Injection AAS with Monolithic Alginate-Polyurethane Composite Packed In-Valve Column

A simple flow injection FlameAAS for lead determination with an alginate-polyurethane composite (ALG-PUC) monolithic in-valve column has been developed. The ALG-PUC monolithic rod was prepared by mixing methylene diphenyl diisocyanate with polyol and sodium alginate with the ratio of 2:1:1 by weight for a 5 min polymerization reaction. It was then put into a column (0.8 cm i.d × 11 cm length) situated in a switching valve for the FI set up. A single standard calibration could be obtained by plotting the loaded µg Pb(2+) vs. FI response (absorbances). The loaded µg Pb(2+) is calculated: μg Pb(2+) = FR(load) × LT × C(Pb)(2+), where the FR load is the flow rate of the loading analyte solution (mL min(−1)), LT is the loading time (min), and C(Pb)(2+) is the Pb(2+) concentration (µg mL(−1)). A linear calibration equation was obtained: FI response (absorbances) = 0.0018 [µg Pb(2+)] + 0.0032, R(2) = 0.9927 for 1–150 µg Pb(2+), and RSD of less than 20% was also obtained. Application of the developed procedure has been demonstrated in real samples.