Establishment and application of mass spectral database for natural dyes
Objective There are different types of natural dyes,including indoles,anthraquinones,naphthoquinones,flavonoids,alkaloids,curcumins,and so on.Facing a large number of textile culture relics,it is impossible to identify quickly the dye compounds only by manual identification using spectral or chromatographic analysis techniques.This research aims to establish a mass spectral database of natural dyes.Using the retrieval technology of the mass spectrum database,the components of natural dyes in textile cultural relics would be identified quickly,bringing efficiency and convenience for the identification of natural dyes in the future.Method In this study,standard natural dye compounds were analyzed by high performance liquid chromatography-mass spectrometry(HPLC-MS),and mass spectrum data were collected.The natural dye mass spectral database was established using National Institute of Standards and Technology(NIST)spectral database software.The search parameters of the software were optimized to achieve the best search results.By comparing the relative peak strength and mass of the unknown mass spectrum with the standard mass spectrum in the database,the similarity between them was identified,and the search result was finally determined.Results Samples of the natural dyes were analyzed by HPLC-MS to obtain their total ion chromatogram data(Tab.1).The appropriate chromatographic peak was selected using Thermo Xcalibur Qual Browser software(Fig.1),the MS/MS spectra of natural dye compounds were exported to NIST MS Search 2.3 software before entering the information of the compounds such as name,formula,molecular weight,synonyms,detection ion mode,retention time,and chemical structure into the self-built mass spectral database.The above operations were repeated until the mass spectral database was established.In order to identify the molecular structure of dye compounds,it is necessary to analyze the mechanism of MS/MS fragmentation.Fragmentation pathways of alizarin,quercetin and luteolin were analyzed,and the derivation of ion information of dye molecular fragments and molecular fragmentation pathway in secondary mass spectral provided an important reference for the identification of natural dye compounds.Using the self-built mass spectrum database,some natural dyes from two textile cultural relics were quickly and accurately identified and the plant origins of the dyes were inferred.In the dye identification of the tricolor sachet,the search result of the mass spectral database showed that the red silk thread contained alizarin and purpurin(Fig.10),which could be inferred as madder dyeing.The yellow silk thread contained jatrorrhizine and berberine(Fig.11),and it was inferred as barberry dyeing.In the dye identification of the silk with striped and floral design,the search results of the mass spectral database showed that the yellow silk thread contained luteolin and apigenin(Fig.12),which was identified as weld dyeing.In addition,in the retrieval process of cultural relics,the match and reverse match scores were both greater than 800,and the matching probability was more than 95%,which was a high score and could substantially confirm the existence of substances.Conclusion The establishment of natural dye mass spectral database can not only shorten the time of dye molecular structure analysis,facilitate fast and accurate identification of dyes in textile cultural relics,but can also reduce the dependence on standard products in dye analysis and reduce the operating cost of the laboratory.This study proved the feasibility and potential of the application of the mass spectral database retrieval technology to the identification of natural dyes and provided a new idea for the follow-up research of natural dyes.
mass spectrometry searchnatural dyehigh performance liquid chromatography-mass spectrometryNational Institute of Standards and Technology mass spectrometry databasemulti-stage mass spectrometry
NETL
NSTL
万方数据
维普
