Development Study of Binding Agent in Diffusive Gradient In Thin Films (DGT) Technique for Absorption of Phosphate Compounds using Nano-La₂O₃

The abundance of phosphate is a concern because it causes problems in aquatic ecosystems. The diffusive gradient in thin films (DGT) technique is a promising method for phosphate absorption because it can be used in situ. The DGT device consists of a membrane filter, a diffusive gel, and a binding gel. The presence of a binding agent in the binding gel makes the specific analyte bound to the binding gel. One of the binding agents that can be used for phosphate absorption is La₂O₃. Binding gel La₂O₃ was successfully synthesized that proven by the similarity of FTIR peaks of the diffusive gel and binding gel. The typical absorption of La-O also proves it from the binding gel at 642 cm^-1 and 423 cm^-1. La₂O₃ binding gel was made of N,-N'-methylenebisacrylamide as a cross-linker with an elution factor of 97.4%. DGT-La₂O₃ proved capable of adsorption for 72 hours, with phosphate absorbed at 1.91 x 10⁵ ng. DGT-La₂O₃ also has the optimum ability to absorb phosphate at pH 3 of 1.93 x 10⁵ ng.