Development And Application Of Rapid,High-throughput Analysis Method Based On Flow Injection Analysis-tandem Mass Spectrometry

Background:Flow injection analysis-mass spectrometry（FIA-MS）is a technique for realizing rapid analysis of samples without chromatographic separation.Because of its rapid analysis speed and high detection flux,it has become an important scientific research tool,which is widely used in the fields of drugs,food,medical diagnosis.However,there is a certain problem in practical analysis（1）Poor sensitivity:the analyte and the matrix in the complex sample are ionized together,which will reduce the ionization efficiency of the analyte,leading to the sensitivity in some cases can not meet the actual detection requirements.（2）Low accuracy:FIA-MS is to inject the sample and matrix into the mass spectrum at the same time,and different degrees of matrix effects will cause the fluctuation of detection signals,resulting in inaccurate quantitative analysis of analytes;（3）Insufficient specificity:the analyte does not have the qualitative indicators provided by retention time,resulting in insufficient specificity of the method.These problems undoubtedly limit the application range of flow injection-mass spectrometry.Objectives:To solve the existing problems of FIA-MS,three quantitative methods were established in this project.（1）To develop a rapid pre-treatment method（liquid microextraction supported by kapok fiber in the syringe）for effective enrichment of analytes and removal of co-existing impurities in the samples,and to improve the sensitivity of FIA-MS while maintaining rapid detection;（2）The signal fluctuation caused by matrix was offset by the internal standard of stable isotope labeling,so as to improve the quantitative accuracy of FIA-MS;（3）High specificity analysis of FIA-MS could be achieved by using both positive and negative ion simultaneous monitoring modes without damaging the flux of the detection method.Contents and Results:（1）Kapok fiber support liquid phase microextraction combined with FIA-MS for detection of antidepressants in body fluidsTo improve the sensitivity of FIA-MS,this study constructed a liquid extraction device supported by kapok fiber in the syringe,which was combined with FIA-MS for the rapid detection of antidepressants in body fluids.The hydrophobic oleophilic property of kapok fiber endows it with the ability to support oily solvents such as n-octanol.Therefore,a simple extraction device could be constructed by placing kapok fiber with n-octanol attached between the needle and syringe.The sample solution was pumped into the syringe through the plunger rod,and part of hydrophobic antidepressants could be quickly extracted to the trace oily solvent attached to the kapok fiber,took a small amount of acetonitrile as a desorbent solvent,thereby achieved the enrichment and rapid impurity removal of the target analyte,and the desorption solution was quickly detected by FIA-MS.To establish a high sensitivity and high throughput rapid analysis method for antidepressants in body fluids.Compared with direct analysis by FIA-MS,the quantitative limit is 5～80 times lower,and the developed syringe extraction technology can be combined with a certain device to achieve automatic pre-processing,which is expected to achieve fully automated analysis.（2）Stable isotope labeling combined with FIA-MS for rapid and high throughput quantitative analysis of 5-hydroxymethylfurfural in drinksTo improve the accuracy of FIA-MS,a method combining stable isotope labeling with FIA-MS was established in this study for the determination of 5-hydroxymethylfurfural（HMF）in drinks.The HMF in the drinks was labeled with ¹²C₆-3-nitrophenylhydrazine（3-NPH）,and the signal fluctuation caused by matrix effect was corrected with the HMF labeled with ¹³C₆-3-NPH as the internal standard during the quantitative analysis of mass spectrometry,then were directly analyzed by FIA-MS after mixing.The HMF labeled with ¹³C₆-3-NPH could be used as an internal standard to correct the signal fluctuation caused by the matrix effect in quantitative analysis of mass spectrometry.Under the optimized derivatization conditions of single-factor analysis,the linearity of the method was good in the range of 50.0～5000.0 ng/m L,the limit of detection and quantitation was 1.0 and 3.3 ng/m L,respectively.The relative recoveries were in the range of 86.1 to 98.5%,and the intra-day and intra-day precision were less than 5.4%.The results show that the method could meet the requirements of quantitative analysis.Compared with other existing methods,this method has the advantages of fast and high throughput.（3）Rapid screening of illegal addition of anabolic-androgenic steroid in healthy foods based on stable isotope labeling combined with FIA-MS in positive/negative ion simultaneous monitoring modeTo improve the specificity of FIA-MS,this study developed a detection method combining stable isotope labeling with FIA-MS in both positive and negative ion monitoring modes,which could be used to quickly detect anabolic-androgenic steroid（AAS）adulterants in healthy foods.The 3-NPH-labeled AAS were bipolar,with proton adjunction ion（[M+H]⁺）detected in positive ion mode and chlorine adjunction ion（[M+Cl]^-）detected in negative ion mode.This method is suitable for rapid screening of illegal addition of AAS in healthy food because it has two qualitative indicators of positive/negative ion mode to improve specificity and maintain fast analysis speed.