Comparison of new optical sensor based on triazene ligand immobilized on PVC and triacetylcellulose membranes for Hg (II) Ion

For spectrophotometric analysis of Hg (II) ions, we have used and compared two membranes preparation methods using different polymer; one is poly(vinyl chloride) (PVC) and the other is triacetylcellulose (TAC). In the case of TAC membrane, it was treated with a ligand solution (1.166 × 10-3 mole L-1) in ethylenediamine at the ambient temperature for almost 2-5 min. However, in the case of PVC membrane, the ligand of triazen was incorporated into a plasticized membrane of PVC. The significant factors affecting the determination of analytical performance from aqueous solutions, limit of detections (LODs) by TAC membrane (64 µg L-1) and by PVC membrane (0.069 ng L-1), linear dynamic range (DLR) by TAC membrane (7-90 mg L-1) and by PVC membrane (0.125-10 µg L-1). In this work LODs and linear dynamic range of PVC membrane is lower than of TAC membrane by a factor of 10000. However, TAC membrane was easier to operate and no more special device required, but PVC membrane required much shorter time reaching to steady state. Two membranes were successfully applied to the determination of Hg (II) in water samples.