| Backgroud:Chromatography-mass spectrometry is a new technology that combines separation technology with detection technology.Among them,chromatography,as a separation system,can provide the most effective selection for the analysis of target compounds in the mixture,and mass spectrometry,as a detection system,has the characteristics of high selectivity,high sensitivity and can provide molecular weight and structure information.This technique combines the high separation ability of chromatography with the strong qualitative ability of mass spectrometry to achieve more accurate qualitative and quantitative analysis of target compounds in complex matrix.In recent years,chromatography-mass spectrometry has been widely used in the fields of drug analysis,environmental analysis,pharmaceutical research and food analysis.Objective:In this paper,a green,fast and sensitive method for detecting electronegative compounds was established based on chromatography-mass spectrometry technology;The complex unknown components in traditional Chinese medicine were analyzed using chromatography-mass spectrometry technology:First,using supramolecular solvent as sample pretreatment method,the electronegative compounds were detected by supercritical fluid chromatography tandem electrospray ionization mass spectrometry based on the post-column charge complex formed by imidazolium-based germinal dicationic ionic liquid.The method was applied to the rapid detection of ten perfluorinated compounds in textile and food packaging materials samples,and the feasibility of the method was verified.Second,fast and comprehensive analysis of the chemical components in pomegranate seeds through ultra-highperformance liquid chromatography coupled with quadrupole-Orbitrap high-resolution mass spectrometry and ultra-high-performance supercritical fluid chromatography-quadrupole-time of flight mass spectrometry,which lays a foundation for the basic research of the medicinal materials of pomegranate seeds,and also provides a basis for the development and utilization of pomegranate seed resources.Research methods and results:Research object 1:development of a new analytical method for detecting electronegative compounds.Based on the concept of green analytical chemistry,a method of supramolecular solvent extraction as sample pretreatment,supercritical fluid chromatography separation,imidazoliumbased germinal dicationic ionic liquid form post-column charge complex,electrospray ionization mass spectrometry analysis for the detection of electronegative compounds was established.Ten kinds of perfluorinated compounds were selected as representative analytes,and supramolecular solvents were used for sample pretreatment.The types and amount of alkyl alcohols,the amount of tetrahydrofuran,extraction time and the amount of supramolecular solvents were investigated by single factor experiment.The interaction of each factor was investigated by response surface experiment.The optimal extraction conditions were as follows:the amount of heptanol was 4 mL,the amount of heptanol was 2 mL,the amount of heptanol supramolecular solvent was 4 mL,extraction time was 3 min.An imidazolium-based germinal dicationic ionic liquid([C4(MIM)2]F2)was dissolved in the make-up solvent of UHPSFC and introduced post-column but before the electrospray ionization(ESI)source.After separation on a Torus Diol column(2.1mm×100 mm,1.7 ?m),the analytes were combined with DIL reagent to form a positively charged complexes.The compounds were qualitatively and quantitatively determined by MRM mode under electrospray ionization positive ion mode.The conditions of chromatographic,mass spectrometry and dicationic ionic liquid which affect the sensitivity of the experiment were optimized and discussed.Under the optimal experimental conditions,the 10 kinds of PFCs were separated rapidly within 6 min,and the formation of positively charged complexes improved the ionization efficiency and analytical sensitivity.Compared with the traditional negative ion mode,the signal intensity in the positive ionization mode was enhanced by one to two magnitudes.Methodological investigation showed that the 10 PFCs showed good linear relationships within their respective linear ranges(r>0.99),LOD ranging from 0.2?1.6 g/kg,LOQ ranging from 0.8?3.2 g/kg,and intra-and inter-day precision ranging from 1.0%?6.9%and 1.1%?8.9%respectively.The recovery rates at three addition levels were71.3%?110.7%,and the relative standard deviations of 0.9%-8.6%.The proposed approach was successfully applied to thirty-two real textile samples and six food packaging material samples.The experimental results revealed the presence of PFDoA(19.85 ?g/kg)and PFOA(12.49 ?g/kg)in one textile sample.The method has good applicability,and the experimental results are basically consistent with the standard method HPLC-ESI-MS/MS detection results,relative errors less than 9%,which proves that the method is sensitive and accurate.This research method is green,fast,reliable and sensitive,which can provide a new technical idea and analytical means for the analysis and detection of electronegative compounds.Research object 2:Analysis of chemical constituents of pomegranate seeds.An ultra-high-performance liquid chromatography coupled with quadrupole-Orbitrap high-resolution mass spectrometry was developed for the rapid identification of chemical constituents in pomegranate seeds.The pomegranate seeds were extracted with methanol by microwave-ultrasonic synergistic extraction method and analyzed according to the established method.Mobile phase A consisted of 0.1%formic acid and water,and mobile phase B consisted of acetonitrile.The determination was performed on ACQUITY UPLC BEH C18 column(2.1 mm×100 mm,1.7 ?m)at flow rate of 0.3 mL/min.The ion source was heated electrospray ionization source,and the scanning mode was positive and negative ion scanning simultaneously.The unknown compounds in pomegranate seeds were identified quickly by the high-resolution mass spectrometry and secondary mass spectrometry information,combined with the Orbitrap Traditional Chinese Medicine Library(OTCML)of Chinese herbal ingredients,relevant literature and standard product mass spectrometry data.A total of 88 compounds were identified under positive and negative ion mode,including 35 flavonoids,7 alkaloids,18 phenolic acids,2 amino acids and 26 other compounds.A rapid method for the identification of pomegranate seeds was established by supercritical fluid chromatographyquadrupole time-of-flight mass spectrometry.60 compounds,including 21 fatty acids,3 sterols,3 vitamins,2 brain glycosides,1 phospholipid and other compounds were identified under negative ion mode.These two kinds of technology to achieve more comprehensive chemical components in pomegranate seed identification.At the same time,the compounds with high content in several identified components were selected as the index compounds,and an ultra-high-performance liquid chromatography coupled with quadrupole-Orbitrap high-resolution mass spectrometry method was established for the simultaneous determination of 12 indexes in pomegranate seeds.The optimized chromatographic and mass spectroscopic conditions showed that the established method was rapid,sensitive and accurate.The 12 compounds were determined in a wide linear range and showed good linear relationships within their respective linear ranges(r>0.99).The recoveries were 81.029%?107.809%,and the intra-day and inter-day precision were 0.880%?7.713%and 0.887%?7.924%,respectively.Research conclusion:In this study,different chromatography-mass spectrometry techniques were used to achieve the qualitative and quantitative study of pomegranate seeds and the green,rapid and high-sensitivity detection of electronegative compounds,which is conformed to the training mode of professional master.In this paper,a new analytical method based on ultra-high performance supercritical fluid chromatograph-electrospray ionization mass spectrometry was established to realize the high sensitivity detection of electronegative compounds.Perfluorinated compounds in textiles and food packaging materials were taken as examples,and the reliability of the method was verified.It can provide new technical ideas and analytical means for the analysis and detection of electronegative compounds.A method for screening and identification of unknown substances was established by ultra-high-performance liquid chromatography coupled with quadrupoleOrbitrap high-resolution mass spectrometry and supercritical fluid chromatography with quadrupole time-of-flight mass spectrometry.The compounds contained in these compounds were studied,the cleavage pathway of each compound was speculated,and the content of multiindex components in pomegranate seeds was determined.It provides a fast and efficient method for the identification of chemical constituents in pomegranate seeds,and provides a strong basis for the study of pharmacokinetics and pharmacology. |
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