Search

CN-121972147-A - DGT (DGT) combined film and preparation method and application thereof

CN121972147ACN 121972147 ACN121972147 ACN 121972147ACN-121972147-A

Abstract

The invention discloses a DGT (DGT) binding membrane, a preparation method and application thereof, wherein the DGT binding membrane comprises HLB (HLB) and XAD18 with the mass ratio of (6.8-7.2) to (2.8-3.2). Through the synergistic effect of the optimized combination of the adsorption phase and the innovative design of the elution program, the invention not only makes remarkable progress in technical performance (recovery rate and detection limit), but also presents great advantages in the aspects of convenience, economy and high efficiency of practical application, and provides a reliable and practical technical tool for developing large-scale and high-standard monitoring of the plastic additives in the water environment.

Inventors

  • TANG YUANYUAN
  • CAO HONGMEI
  • SONG RUI

Assignees

  • 南方科技大学

Dates

Publication Date
20260505
Application Date
20260325

Claims (10)

  1. 1. A DGT binding membrane, comprising an HLB to XAD18 mass ratio of (6.8-7.2): 2.8-3.2.
  2. 2. The DGT binding membrane according to claim 1, wherein the method of preparing the binding membrane comprises the steps of: Mixing HLB powder and XAD18 powder according to the mass ratio of (6.8-7.2) (2.8-3.2) to obtain resin powder, weighing agarose powder and resin powder according to the mass ratio of (0.5-0.6) (3.9-4.2), placing the agarose powder and the resin powder in a syringe, adding methanol, standing for activation for 25-40 min, and adding ultrapure water for flushing; Weighing agarose powder and completely washed resin powder according to the mass ratio of (0.5-0.6) (3.9-4.2), putting the agarose powder and the completely washed resin powder into a beaker, adding ultrapure water, heating and stirring to obtain a thermal gel solution, pouring the thermal gel solution into a preheated porous glass mould, pouring the solution with the thickness of 0.45-0.55 mm, covering a glass plate, and cooling the gel to room temperature to obtain the bonding film.
  3. 3. A DGT device comprising a filtration membrane, a diffusion membrane and a DGT combining membrane according to any one of claims 1-2.
  4. 4. A DGT device according to claim 3, wherein the filter membrane is a hydrophilic PTFE membrane.
  5. 5. A DGT device according to claim 3, wherein the method of preparing the diffusion film comprises the steps of: Dissolving agarose powder in ultrapure water, heating and fully stirring until the solution becomes clear to obtain a thermal gel solution, pouring the thermal gel solution into a preheated porous glass mold, pouring the solution into a mold with the thickness of 0.75-0.85 mm, covering a glass plate, and cooling the gel to room temperature to obtain the diffusion membrane.
  6. 6. The DGT device according to claim 5, wherein the porous glass mould is a six-hole glass mould.
  7. 7. Use of a DGT device according to any one of claims 3 to 6 in the field of organic contaminant monitoring.
  8. 8. The use according to claim 7, comprising an adsorption procedure and an elution procedure, wherein the elution procedure is to remove the binding membrane in the DGT device after the adsorption procedure and to subject it to ultrasound elution in an eluent.
  9. 9. The use according to claim 8, wherein the elution procedure is performed using a solution of acetonitrile to ethyl acetate to acetone in a volume ratio of (9.8-10.3): 2.9-3.2): 1.9-2.2.
  10. 10. The use according to claim 7, wherein the organic contaminant is any one or more of a plasticizer, an antioxidant, a flame retardant.

Description

DGT (DGT) combined film and preparation method and application thereof Technical Field The invention relates to the technical field of DGT, in particular to a DGT combined film and a preparation method and application thereof. Background Plastic additives in surface water environments, such as plasticizers, antioxidants, flame retardants, etc., have become a global emerging contaminant. These compounds are usually present at trace or ultra trace levels (ng/L to μg/L), but can pose a potential threat to the aquatic ecosystem and human health due to their endocrine disruptors, carcinogenicity, and bioaccumulation. Accurate monitoring of the environmental concentration of these contaminants is a prerequisite for ecological risk assessment and pollution abatement. However, the traditional active Sampling technology (such as instantaneous grabbing Sampling) has obvious limitations that firstly, the conventional grabbing Sampling (Grab Sampling) has instantaneous characteristics, only the water sample concentration at the Sampling moment can be obtained, the concentration of the plastic additive is greatly influenced by emission, day-and-night variation, rainfall runoff impact, hydrologic conditions and the like, so that the time weighted average concentration of the single Sampling result cannot be accurately reflected, the single Sampling result is difficult to be used for accurate environmental risk assessment, namely the conventional Sampling technology cannot overcome the influence of the fluctuation of the pollutant concentration along with the time, the single Sampling result is not representative, secondly, the operation is complicated and the cost is high, the conventional grabbing Sampling needs to be frequently carried out on site, and a large amount of water samples are immediately transported back to a laboratory for pretreatment and enrichment (such as solid phase extraction and SPE), the process is complicated, pollution is easily introduced or target object degradation is easily caused in the transportation and preservation processes, and manpower is manpower, and thirdly, the detection limit has challenges, for ultra-trace pollutants, water samples with the volume of tens of liters to hundreds of liters need to be collected and processed, the enrichment process is complex, the background interference is large, and the sensitivity and the accuracy are difficult to ensure. The diffusion gradient technology (Diffusive GRADIENTS IN THIN-films, DGT) is an in-situ passive sampling technology, the basic principle is that a binding phase in the device can continuously and selectively adsorb a target object through a diffusion gel layer, so that the time weighted average concentration (TWA) in a period of time is enriched, the transient defect of active sampling is effectively overcome, the DGT technology is successfully applied to monitoring of metal ions initially, and the DGT technology is expanded to monitoring of organic pollutants and is a research hotspot in the current environmental analysis field. In recent years, researchers have tried to use various materials as a binding phase of a DGT device for collecting organic pollutants in water, the existing adsorption materials, such as MOFs, have the problems of poor water stability, high cost and slow template molecule leakage and kinetics, and the functionalized resins and the composite materials are generally limited by the defects of insufficient adsorption capacity, poor selectivity, complex preparation process and the like, and the limitations severely restrict the application of the functionalized resins and the composite materials in the reliable and efficient passive sampling of trace plastic additives in complex surface water environments. Many passive samplers are based on equilibrium principles, require accurate knowledge of sampling rate (Rs) or time to reach equilibrium, which is difficult to calculate accurately in complex and varying environmental bodies of water, resulting in large quantitative errors, and the current commercial adsorption resins are prepared with a narrow range of bound membrane applicable contaminants, generally optimized for only certain specific classes of contaminants, such as hydrophobic persistent organic contaminants, lacking a universal sampling medium with high and known adsorption properties for a wide range of plastic additives. Therefore, there is a need to develop a DGT monitoring device capable of in-situ, sensitive, time-integrated and passive sampling of organic contaminants and a DGT-binding membrane with high elution efficiency, which can be practically applied in large-scale environmental monitoring. Disclosure of Invention Aiming at the defects in the prior art, the invention provides a DGT combined film and a preparation method and application thereof. The invention aims to solve the technical bottleneck existing in the prior art when trace/ultra trace organic plastic additives in surface