Visual determination of lead(II) by inhibition of alkaline phosphatase immobilized on polyurethane foam Original Research Article

The inhibitory effect of lead(II) towards the activity of alkaline phosphatase immobilized in N-phthalylchitosan on polyurethane foam in p-nitrophenylphosphate hydrolysis has been used for developing a visual test procedure for the determination of 0.05–10 000 ng ml−1 Pb(II). The 3σ detection limit is 0.02 ng ml−1. Alkaline phosphatase immobilized on polyurethane foam keeps the catalytic activity for at least 1 year. The developed procedure was applied successfully to the determination of lead (14–91 mg kg−1) in different types of soils.