On-Line Preconcentration/Determination of Lead Traces in Bee Honey by Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) Using a Conical Minicolumn Packed with Activated Carbon

Abstract

In this study, the preconcentration of Pb²⁺ using a conical minicolumn packed with activated carbon (AC) was studied for preconcentration of Pb²⁺. The experiments showed that Pb²⁺ reacts with 8-hydroxyquinoline to form a complex at pH 10.0 and can be retained “on-line” on a conical minicolumn packed with activated carbon, then eluted with 20% (v/v) nitric acid. The conditions for the quantitative and reproducible preconcentration and subsequent ICP-OES determination with ultrasonic nebulization system (USN) were studied. A total enhancement factor (N) of 500 was obtained with respect to ICP-OES using pneumatic nebulization (10 for USN and 50 for enrichment factor) for a sample volume of 25 mL. The detection limit (DL) was 0.04 µg L⁻¹. The relative standard deviation (RSD) were 3.0%. The optimized procedure was successfully applied to the determination of trace levels of Pb⁺² in bee honey samples.

Keywords:

• Lead determination
• On-line preconcentration
• Activated carbon
• Bee honey

Acknowledgments

This work was supported by Universidad Nacional de San Luis; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); Agencia Nacional de Promoción Científica y Tecnológica (FONCYT) (PICT-BID).