Application Of Transition Metal Oxide Nanomaterials In Detection Of Environmental Pollutants By High-throughput Mass Spectrometry

Nanomaterials have many special properties,such as large surface area,good adsorption performance,small pore size,good photoelectric perfo rmance,and have been widely used in various fields such as adsorption and purification,photocatalysis,electrochemistry,microelectronics,and ceramics.High-throughput mass spectrometry is a simple,rapid and sensitive analytical detection technology that plays a very important role in proteomics research,ecological environment health and food safety.Dyes and chemicals are indispensable substances in social life and are the main source of environmental pollutants,causing great harm to human health and living environment.Therefore,it is very important to detect quickly and sensitively the environmental pollutant molecules for the protection of ecological environment.When using inorganic nanomaterials as mass spectrometry matrix or probe,its strong l ight absorption capacity and energy transfer ability can improve the desorption ionization efficiency of the target analyte,and its adsorption performance can enrich the target analyte.In this paper,two kinds of transition metal oxide nanomaterials were developed and prepared,and their special structures and properties were used to study the high-throughput sensitive detection of dye molecules and emerging environmental pollutants in complex environmental samples with high-throughput mass spectrometry technology.The main contents are as follows:（1）Preparation of TiO₂ nanoflakes and rapid SALDI-TOF MS detection of toxic small molecules.Two-dimensional porous TiO₂ nanoflakes were synthesized by hot solvent method,and the adsorption effects of TiO₂ nanoflakes on several dye molecules were studied.The performance as a mass spectrometry matrix was explored and compared to commercial TiO₂ and two conventional organic matrices.The experimental results show that TiO₂ nanoflakes can be used as an excellent mass spectrometry matrix to detect small molecules in the low molecular w eight range,and the detection effect depends on the target analyte.Some analytes can show obvious mass spectrometry signals,while others can not.The detection limit range is 0.001-10pg/mL,the reproducibility is good,and the background noise of matrix is low.Using TiO₂ nanoflakes as the surface assisted laser desorption ionization（SALDI）matrix,malachite green and its metabolite leuco malachite green were detected from fish blood and fish muscle extracts,and crystal violet and its homologues were detected from ink on supermarket receipt paper.（2）Bi_x Fe_y Ti_z-ZrO₂ nanocomposites were used as mass spectrometry probes for the rapid detection of bisphenol A and tetrabromobisphenol A in tea.The doped modified Bi_x Fe_y Ti_z-ZrO₂ nanocomposites were prepared by sol-gel method.The sensitivity and reproducibility of this material as SALDI matrix for detecting small molecules of environmental pollutants（dye molecules and emerging environmental pollutants）is better.The background interference is small,and the detection limit range is 0.001-100 pg/mL.The mass spectrum intensity variation error of different locations on the target surface and different batches of the same sample target is less than 15%,with good uniformity and reproducibility.Using this material as a SALDI matrix and surface enhanced laser desorption ionization（SELDI）probe,we quickly detected bisphenol A and tetrabromobisphenol A from actual tea samples,and the mass spectrometry detection effect of the material as SELDI probe was superior to that of the material alone as a SALDI matrix.This method has great application value for simultaneous determination of bisphenol A and tetrabromobisphenol A in tea samples.