Rapid authentication of different herbal medicines by heating online extraction electrospray ionization mass spectrometry

The rapid and accurate authentication of traditional Chinese medicines(TCMs)has always been a key scientific and technical problem in the field of pharmaceutical analysis.Herein,a novel heating online extraction electrospray ionization mass spectrometry(H-oEESI-MS)was developed for the rapid and direct analysis of extremely complex substances without the requirement for any sample pretreatment or pre-separation steps.The overall molecular profile and fragment structure features of various herbal medicines could be completely captured within 10–15 s,with minimal sample(<0.5 mg)and solvent consumption(<20μL for one sample).Furthermore,a rapid differentiation and authentication strategy for TCMs based on H-oEESI-MS was proposed,including metabolic profile characterization,characteristic marker screening and identification,and multivariate statistical analysis model validation.In an analysis of 52 batches of seven types of Aconitum medicinal materials,20 and 21 key compounds were screened out as the characteristic markers of raw and processed Aconitum herbal medicines,respectively,and the possible structures of all the characteristic markers were comprehensively identified based on Compound Discoverer databases.Finally,multivariate statistical analysis showed that all the different types of herbal medicines were well differentiated and identified(R^(2)X>0.87,R^(2)Y>0.91,and Q^(2)>0.72),which further verified the feasibility and reliability of this comprehensive strategy for the rapid authentication of different TCMs based on H-oEESI-MS.In summary,this rapid authentication strategy realized the ultra-high-throughput,low-cost,and standardized detection of various complex TCMs for the first time,thereby demonstrating wide applicability and value for the development of quality standards for TCMs.

Application of Online Solid-phase Extraction Technology in the Field of Environmental Analysis

For purpose of purification and enrichment, environmental samples usually need to be pretreated before analysis because of low concentration of residual organic matters. Solid-phase extraction （SPE） is one of the frequently used methods of pretreatment. This article introduces the methodological principle and flow channel of SPE as well as the categories of frequently used small extraction column, analyzes the application of online SPE technology in environmental analysis, generalizes the advantages of online SPE and sets forth its developmental trend.

Dithizone-functionalized C18 online solid-phase extraction-HPLC-ICP-MS for speciation of ultra-trace organic and inorganic mercury in cereals and environmental samples

A simple and efficient dithizone-functionalized solid-phase extraction(SPE)procedure,online coupled with high-performance liquid chromatography(HPLC)-inductively coupled plasma mass spectrometry,was developed for the first time for enrichment and determination of ultra-trace mercury(Hg)species(inorganic divalent Hg(Hg(Ⅱ)),methylmercury(CH_(3)Hg(Ⅱ))and ethylmercury(C_(2)H_(5)Hg(Ⅱ))in cereals and environmental samples.In the proposed method,functionalization of the commercial C_(18) column with dithizone,enrichment,and elution of the above Hg species can be completed online with the developed SPE device.A simple solution of 2-mercaptoethanol(1%(V/V))could be used as an eluent for both the SPE and HPLC separation of Hg species,significantly simplifying the method and instrumen-tation.The online SPE method was optimized by varying dithizone dose,2-mercaptoethanol concentration,and sample volume.In addition,the effect of pH,coexisting interfering ions,and salt effect on the enrichment was also discussed.Under the optimized conditions,the detection limits of Hg species for 5 mL water sample were 0.15 ng/L for Hg(Ⅱ),0.07 ng/L for CH_(3)Hg(Ⅱ),and 0.04 ng/L for C_(2)H_(5)Hg(Ⅱ)with recoveries in the range of 85%-100%.The developed dithizone-functionalized C_(18) SPE column can be reused after a single function-alization,which significantly simplifies the enrichment step.Moreover,the stability of Hg species enriched on the SPE column demonstrated its suitability for field sampling of Hg species for later laboratory analysis.This environment-friendly method offers a robust tool to detect ultra-trace Hg species in cereals and environmental samples.

Design and Implementation of Prototype System for Online Handwritten Uyghur Character Recognition

Based on the analysis of the unique shapes and writing styles of Uyghur characters,we design a framework for prototype character recognition system and carry out a systematic theoretical and experimental research on its modules.In the preprocessing procedure,we use the linear and nonlinear normalization based on dot density method.Both structural and statistical features are extracted due to the fact that there are some very similar characters in Uyghur literature.In clustering analysis,we adopt the dynamic clustering algorithm based on the minimum spanning tree（MST）,and use the k-nearest neighbor matching classification as classifier.The testing results of prototype system show that the recognition rates for characters of the four different types（independent,suffix,intermediate,and initial type） are 74.67%,70.42%,63.33%,and 72.02%,respectively;the recognition rates for the case of five candidates for those characters are 94.34%,94.19%,93.15%,and 95.86%,respectively.The ideas and methods used in this paper have some commonality and usefulness for the recognition of other characters that belong to Altaic languages family.