On-line microwave slurry sample digestion using flow systems for the spectrophotometric determination of iron in seafood†

Abstract

A method for the spectrophotometric determination of iron in seafood slurry samples based on microwave assisted digestion has been developed. The stabilized slurry (200 µl) is introduced in a flow system and transported by an air carrier stream to a digestion coil positioned inside the microwave oven. After the digestion step (10 or 20 min at maximum power) the flushing solution is collected in a calibrated flask. A 200 µl-digested sample is introduced in a flow injection system and the iron determined at 512 nm with 1,10-phenanthroline. The proposed method features a linear range from 50 to 200 µg l^–1 (r > 0.999) presenting a precision, expressed as RSD, of 3.7% (n = 10) for repeatability and 5.0% (n = 30) for reproducibility. Accuracy was assessed by using Standard and Certified Reference Materials.