Flow-injection method for the determination of tin in fruit juices using solid-phase spectrophotometry

An integrated solid-phase spectrophotometric-flow-injection method is proposed for the determination of tin in fruit juices. The complex formed between Sn(IV) and Pyrocatechol Violet in the flow system is concentrated on Sephadex QAE A-25 gel packed in a flow cell. The analytes are monitored by UV-visible spectrophotometry at 576 nm. The method shows a detection limit of 0.3 ng ml−1 and a linear range of 2–40 ng ml−1.