Flow injection determination of levodopa in tablets using a solid-phase reactor containing lead(IV) dioxide immobilized.

A flow injection spectrophotometric procedure was developed for determining levodopa in tablets. The determination of this drug was carried out by reacting it with lead(IV) dioxide immobilized in polyester resin packed in a solid-phase reactor and the dopachrome yielded was monitored at 520 nm. The analytical curve for levodopa was linear in the concentration range from 1.0x10(-4) to 1.0x10(-3) mol l(-1) with a detection limit of 8.0x10(-5) mol l(-1). The relative standard deviation (R.S.D.) was 0.2% for a solution containing 4.0x10(-4) mol l(-1) levodopa (n=10), and 90 determinations per hour were obtained.