A kind of dtpa modified material and its fast total dissociation dgt binding phase preparation method

Abstract

The present invention relates to a kind of DTPA modified material and the preparation method of fast full-dissociation type DGT binding phase prepared thereof, utilize DTPA to react with Mg2+, Al3+ under alkaline conditions (1) add 24.4ml ammonia water (NH4(OH) to 73.20ml water ) and methanol. Then 32.78g of DTPA was added and fully dissolved. (2) Take another beaker, add 593.34ml of water and 197.78ml of ammonia water, and mix well. (3) Add the solution obtained in steps (1) and (2) to the solution containing MgCl2 6H2O and AlCl3 6H2O to obtain a DTPA modified material, pass through a 200 mesh (75 μm) sieve after spray drying to form a heavy metal adsorption material for DGT binding film, and then add The polyacrylamide gel solution reacts at a certain temperature to form a DGT binding film. The gel film prepared by the method has the effect of absorbing heavy metals and dissociates completely in a short time, and overcomes the disadvantage of slow and incomplete dissociation of heavy metal binding phases in the past. Moreover, the materials used are cheap and easy to prepare, and no secondary pollution occurs, which is beneficial to popularization and application of the DGT technology.

Description

technical field [0001] The invention belongs to the field of heavy metal detection, and relates to a method for preparing a combined phase gel film of DGT (Diffusive gradients in thin films, DGT) for easy dynamic extraction of heavy metals in the analysis of environmental media such as water bodies, soils and sediments. Background technique [0002] In recent years, the problem of heavy metal pollution in soil, water and sediment has become more prominent, causing a series of environmental and ecological hazards, such as the cadmium rice incident caused by soil pollution, and the Minamata disease incident caused by water pollution. In order to more scientifically evaluate the real pollution status of heavy metals in different media and analyze their pollution hazards, in 1994, DGT (Diffusive gradients in thin-films) technology came into being. The binding phase is one of the core components of DGT. Its function is to quickly adsorb the easily dynamic heavy metals passing thr...

AI Technical Summary

Problems solved by technology

[0003] Usually DGT binding phase adsorbs heavy metal materials mostly chelex-100, zirconium dioxide, titanium dioxide and nano-iron oxide. Although these materials can efficiently adsorb heavy metals and dissociate in acid or alkali solvents, the dissociation time is long and the decomposition Incomplete, the shortcomings are reflected in: on the one hand, it increases the detection time of DGT, and on the other hand, it is easy to cause deviations in the detection results

[0004] In view of the above problems, the present invention proposes a method for preparing DGT binding membrane based on DTPA modified material, which can effectively solve the problem of long dissociation time and incomplete dissociation of DGT binding membrane

Images