Abstract: A sequential injection renewable surface reflectance spectrophotometric system employing a microchip flow cell was developed. The double layer microchip flow cell with a weir structure for bead collection was fabricated on glass chips using a standard photolithographic procedure followed by thermal bonding. The flow cell was coupled to a sequential injection system and an optical fiber photometric detection system. The SI-RST analysis system was applied to the determination of trace amounts of zinc by reflectance spectrophotometry. The analyte reacted with zinc sorbed on Polysorb C18 beads trapped in the flow cell. The proposed method was successfully applied to the determination of zinc in human hair.