Analysis of Volatile Components in Fresh Fruit of Morinda citrifolia L.from Different Origins Based on HS-SPME-GC/MS

[Objectives]This study was conducted to clarify the differences of volatile components in fresh fruit of Morinda citrifolia L.from different origins.[Methods]The method of HS-SPME-GC/MS detection was used to determine the volatile chemical components in fresh fruit of M.citrifolia.[Results]52,52 and 45 volatile components were identified from the fresh fruit of M.citrifolia from Xisha,Wanning and Haikou,respectively.Among them,the number and content of the identified esters were relatively high,mainly methyl caprylate,ethyl caprylate,4-pentenyl caproate,3-methylbuten-2-enyl caprylate,methyl caproate,and ethyl caproate.There were also fatty acids,alcohols,phenols,ketones,aldehydes and other substances.There were 33 common ingredients in the fruit from the three origins,mainly including caprylic acid,caproic acid,capric acid,methyl caprylate,ethyl caprylate,4-pentenyl caproate,3-methylbutene-2-enyl caprylate,methyl caproate,ethyl caproate,methyl caprate and hexyl caproate.[Conclusions]The types and contents of volatile components in fresh fruit of M.citrifolia from different origins were significantly different.

SPECIATION OF Cu、Pb、Zn、Cr IN DUST OF DIFFERENT ORIGINS AND DIAMETERS

Various species of Cu.Pb,Zn and Cr in dust of different origins and diameters were studied using Tessler scheme,and the partition law was revealed, The results indicated that superior form of Cu、Pb、 Zn and Cr was bound to organic master,bound to Fe-Mn oxides,bound to Fe-Mn oxides and residual.So their activity order was Zn>Pb>Cu>Cr.The exchangeable metals bound to carbonates and Fe-Mn oxides of four heary metals in small particles were superior to those in large particles,which illustrated that heavy metals in small paticles were more active and harmful.

Comparison of Heavy Rainfall Events Originated from Different Directions of Beijing City

Strong rainfall events originated from the northeast(NE)and southwest(SW)directions of the plain area of Beijing City(BJP)over 8 recent warm seasons(May–September of 2009–2016)were analyzed by using hourly merged rainfall,satellite brightness temperature,and the fifth-generation ECMWF reanalysis(ERA5)data.Such heavy regional rainfall events(RREs)with different origins present quite different features in both the precipitation itself and its corresponding circulations.The heavy RREs originated from the SW occur more frequently in the flood season of North China(July and August),and the peak time of rainfall occurrences is in the early morning.They are linked with stronger large-scale circulation forcing,compared with the NE-originated events.Meanwhile,the ratio of heavy rainfall to the total rainfall in SW-originated events,the mean spatial coverage of rainfall,and associated convective index,are also larger,for the SW events.The heavy RREs from the NE occur more frequently in June and July(before the traditional flood season),with a more apparent afternoon peak.They exhibit stronger convective features,with higher maximum convective index values,but the large-scale forcing is weaker at the hour of onset.These features of the RREs from different directions of Beijing City and associated precursor circulation signals help better forecast RREs over the BJP.

A combined quality evaluation method that integrates chemical constituents, appearance traits and origins of raw Rehmanniae Radix pieces

The quality control of Chinese herbal medicine is a current challenge for the internationalization of traditional Chinese medicine.Traditional quality evaluation methods lack quantitative analysis,while modern quality evaluation methods ignore the origins and appearance traits.Therefore,an integrated quality evaluation method is urgent in need.Raw Rehmanniae Radix(RRR)is commonly used in Chinese herbal medicine.At present,much attention has been drwan towards its quality control,which however is limited by the existing quality evaluation methods.The present study was designed to establish a comprehensive and practical method for the quality evaluation and control of RRR pieces based on its chemical constituents,appearance traits and origins.Thirty-three batches of RRR pieces were collected from six provinces,while high-performance liquid chromatography(HPLC)was applied to determine the following five constituents,including catalpol,rehmannioside A,rehmannioside D,leonuride and verbascoside in RRR pieces.Their appearance traits were quantitatively observed.Furthermore,correlation analysis,principal components analysis(PCA),cluster analysis and t-test were performed to evaluate the qualities of RRR pieces.These batches of RRR pieces were divided into three categories:samples from Henan province,samples from Shandong and Shanxi provinces,and those from other provinces.Furthermore,the chemical constituents and appearance traits of RRR pieces were significantly different from diverse origins.The combined method of chemical contituents,appearance traits and origins can distinguish RRR pieces with different qualities,which provides basic reference for the quality control of Chinese herbal medicine.