Determination of Mo(vi) in water with poly(quaternary ammonium salt) as a binding phase of diffusive gradients in thin-films

Abstract

A technique of diffusive gradients in thin films (DGT) for the measurement of Mo(VI) in water was developed using poly(quaternary ammonium salt) (PQAS) solution as the binding phase in the liquid-type DGT device (PQAS DGT). The Mo(VI) uptake by PQAS DGT increased linearly with time (r² = 0.9989) with a recovery of 98.8% in synthetic solution. The DGT performance was independent of solution pH over the pH range of 4–10 and ionic strength range from 0.0001 to 0.1 mol L⁻¹ NaNO₃. The concentration of Mo(VI) in river water determined by PQAS DGT was 3.21 μg L⁻¹, and the recoveries of the spiked Mo(VI) were 97.3–101.5%. The results show that PQAS can be used as a binding phase in the liquid-type DGT device for the measurement of Mo(VI) in water.