Flow injection determination of copper and iron in seafoods by a continuous ultrasound-assisted extraction system coupled to FAAS

Abstract

Copper and iron were extracted on-line from solid seafood samples by a robust, fast and simple continuous ultrasound-assisted extraction system (CUES). CUES is connected to a flow-injection manifold, which allows on-line flame atomic absorption spectrometric determination of copper and iron. Experimental designs were used to optimize the continuous leaching procedures. These methods allowed a total sampling frequency of 46 and 18 samples per hour, with relative standard deviations of 1.6% and 0.3%, for copper and iron, respectively (for a sample containing 13.6 µg/g of copper and 217.3 µg/g of iron (dry mass)). The limits of detection for 30 mg of sample were 0.3 µg/g for copper and 0.6 µg/g for iron (dry mass). Analytical procedures were verified by the analysis of a standard reference material (lobster hepatopancreas marine, TORT-1) and were applied to several real seafood samples from the estuaries of Galicia (Spain) with satisfactory results.

Keywords:

• Continuous ultrasound-assisted extraction system
• Flame atomic absorption spectrometry
• Copper determination
• Iron determination
• Seafood samples

Acknowledgements

The authors are grateful for the financial support provided by the Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Ministerio de Ciencia y Tecnología (Project no. CAL01-043). A.M.C.B. acknowledges a grant from the Ministerio de Educación, Cultura y Deporte, Ap 2001-0367.