Green And Efficient Sample Pre-processing Technology Based On Real-time Direct Analysis Of Mass Spectrometry

Because the advantages of mass spectrometry lie in automation,high sensitivity,and specificity,and the structural information of compounds,it is widely used in pharmaceutical,chemical,petroleum,and environmental fields.However,conventional mass spectrometers need to be combined with chromatography,and the analysis efficiency is low,where complex sample pretreatment is required.It is hard to achieve high-throughput analysis.Direct analysis in real time mass spectrometry?DART-MS?is a new type of ambient ionization mass spectrometry that has attract much attention in recent years.It can directly detect gaseous,liquid,and solid substances under atmospheric pressure.It requires less voulume of samples and is a high throughput analytical method.An analysis of a sample can usually be completed within 30 seconds.No organic solvent is required in the process,which is suitable for the qualitative and quantitative detection of small molecule compounds.Because of the complicated matrix,the existence of impurities and the low concentration of analytes,it is difficult to apply DART-MS for direct analysis.Therefore,the sample needs to be pretreated before analysis.Traditional sample preparation techniques are time consuming and laborious,tedious and consume a large amount of organic solvents,which causes damage to the environment.Therefore,we developed a variety of efficient and eco-friendly sample preparation methodologies based on DART-MS for the analysis of pollutants in water and natural products in plants.The specific content is as follows:?1?In this study,a method based on the dispersive solid phase extraction?DSPE?combined with DART-MS analysis are developed for the enrichment and detection of phenoxycarboxylic acid?PCAs?herbicides in water samples.In this experiment,Vg-C₃N₄ was synthesized as the adsorbent for DSPE.Three phenoxycarboxylic acid herbicides in water samples were enriched and the adsorption conditions were optimized by HPLC.The quantitative analysis was applied by adding an internal standard.Under the best experimental conditions,The limit of detection ranged from0.5 ng/L to 2 ng/L on the basis of 50 m L water sample;the recovery 79.9-119.1%;and the relative standard deviation 0.23%-9.82%.With the ease of use and speed of DART-MS,the whole protocol can complete within mere minutes.The methodology developed here is simple,fast,sensitive and accurate.It requiring little sample preparation and consuming significantly less toxic organic solvent,which can be used for high throughput screening of PCAs and potentially other contaminants in water.?2?Solvent-free high-throughput analysis of herbicides in environmental water.In this experiment,three metal-organic framework?MOFs?materials were synthesized as the coating of solid-phase microextraction fibers for the enrichment of four triazine herbicides in water samples.DART-MS was applied for the quantitative analysis.Under the best experimental conditions,the LODs of the target compounds were 5.0-50.0 ng/L,the spiked recoveries were 92.4-125.7%,and the RSD was less than 12.2%.In this research,we established a high-throughput and environmentally friendly analytical method based on solid-phase microextraction combined with DART-MS,which can be used to determine trace pollutants in water.?3?High-throughput analysis for artemisinins with deep eutectic solvents mechanochemical extraction and direct analysis in real time mass spectrometry.In this experiment,twelve DESs were synthesized and formulated into different concentrations of water or ethanol solutions as extraction solvents for mechanochemical extraction.The extraction solvent and conditions were optimized using HPLC.Quantitative analysis was performed for Artemisia annua from five producing areas.The results showed that the LODs of the target compounds were 5-15ng/m L,the spiked recoveries were 80.9-119.8%,and the RSD was 0.7-10.8%.It takes only a few minutes to obtain the results with this methodology.This study aims to establish a methodology combining high-efficiency sample pretreatment and rapid chemical analysis from complex matrixes,where the time-consuming separation procedure can be eliminated.?4?Extraction of anthraquinones from rhubarb by microwave extraction method based on DESs.In this experiment,nine DESs were prepared and formulated into different concentrations of aqueous solutions.The heating rate and the reaction with glucose in the microwave extraction apparatus were investigated.By using response surface methodology?RSM?,the extracted amount of four anthraquinones were obtained by LC-UV.The results showed that under the optimal extraction conditions,the extracted amount of aloe-emodin was 2.09±0.09 mg/g,emodin was 2.30±0.15 mg/g,emodin was 35.44±0.71 mg/g,and emodin methyl ether was 18.80±0.09 mg/g.It can be a potential sample preparation method combined with DART-MS analysis.