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Inspired by dried blood spots (DBS), “dried spots of herbal medicines” (DSHM) concept was proposed here. In response to this superior sampling means, a new platform integrating dried spot, serially coupled reversed phase liquid chromatography and hydrophilic interaction liquid chromatography (RPLC-HILIC), and tandem mass spectrometry (MS/MS), was configured for directly, comprehensively chemical profiling of HM-derived liquid matrices. As an important original source of Cistanches Herba (Chinese name: Roucongrong) that is a well-known tonic HM, Cistanche sinensis (Csi) was employed to illustrate and validate the applicability. Dried spots (I.D. 3.0 mm) were prepared by loading 2 μL aliquots of Csi extract onto filter paper. Each dried spot was packed into an in-line filter holder (I.D. 3.0 mm × 4.0 mm) and then inserted behind the auto-sampler of a well-defined instrumentation named RPLC-HILIC–MS/MS. Hybrid ion trap-time of flight MS and hybrid triple quadrupole-linear ion trap MS were deployed in combination for the in-depth MS/MS data acquisition of diverse chemical families, such as phenylethanoid glycosides, lignans, iridoids, amino acids, and so forth. To assist chemical profiling, an in-house chemical library was built by collecting as much prior knowledge as possible. A total of 88 components were detected and tentatively annotated in Csi by matching their multi-stage MS spectra with those of authentic standards and literature data. Collectively, DSHM carried all merits of DBS, and the integrative dried spot-RPLC-HILIC-MS/MS platform was a promising analytical tool for direct chemical analysis and rapid quality evaluation of HMs, in particular those traditional Chinese medicine injections.

Bile acids( BAs),the major constituents of bile,are also known to be potential biomarkers of various diseases,especially liver disease. The systematic analysis of BAs is believed to be of great importance towards the clarification of the effective material basis for bile-type medicines,and the diagnosis and therapy of related diseases as well. As a part of systematic study on bile-type medicine ongoing in our group,this study lays emphasis on the isomer discrimination,and the improvement of analytical method of BAs. Further,this method was subsequently applied to elucidate in depth the chemical profile of BAs in yak bile. Regarding isomer discrimination for BAs,we constructed relative response-collision energy curves( RRCECs) by high performance liquid chromatographyion trap-time of flight-mass spectrometry( HPLC-IT-TOF-MS) in combination with high performance liquid chromatography-triple quadrupole-linear ion trap mass spectrometry( HPLC-Qtrap-MS). As a result,both the optimum collision energy( OCE) and CE_(50) exhibited great correlations with structural characteristics,thus enabling the isomer distinguishing,such as unconjugated BAs,glycine-conjugated BAs,and taurine-conjugated BAs. According to information provided by mass spectrometry,the comparison of OCE and CE_(50),retention time matching,combined with reference substances and database retrieval,a total of 30 bile acid derivatives were observed and identified in yak bile. The newly developed method could serve as a feasible tool for the in-depth characterization of BAs in bile and biological samples.