Selective sampling and measurement of Cr (VI) in water with polyquaternary ammonium salt as a binding agent in diffusive gradients in thin-films technique

- We develop a new DGT device for in situ sampling Cr (VI) in water.
- Polyquaternary ammonium salt (PQAS) was used as binding agent of DGT device.
- Cr (VI) can be accumulated in the PQAS binding phase whereas Cr (III) cannot.
- The DGT performance was independent of pH 3-12 and ionic strength 1 × 10−3-1 mol L−1.