COMPREHENSIVE TWO-DIMENSIONAL LIQUID CHROMATOGRAPHY COUPLED WITH QUADRUPLE TIME-OF-FLIGHT MASS SPECTROMETRY FOR CHEMICAL CONSTITUENTS ANALYSIS OF TRIPTERYGIUM GLYCOSIDES TABLETS

Comprehensive two-dimensional liquid chromatography platform(LC×LC)coupled with quadrupole time-of-flight(QTOF)mass spectrometry(MS)is developed to separate,identify and relatively determine the chemical constituents of two types of tripterygium glycosides tablets(TGT).The types and relative contents of the constituents discovered in two kinds of TGT tablets were subsequently compared.C8andC18 column were used for the separation of the first

Rapid Screening of Nine Illicit Drugs in Human Blood and Urine by Direct Analysis in Real‑Time Mass Spectrometry

We aimed to establish for the rapid detection of morphine,O6‑monoacetylmorphine,heroin,codeine,cocaine,methamphetamine,ketamine,methadone,and dolantin in human blood and urine by direct analysis in real‑time coupled with tandem mass spectrometry(DART‑MS/MS).These samples were extracted by acetonitrile‑methanol(V/V=4:1),using DART 12 Dip‑it automatic sampling system.They were injected at 400℃,and analyzed by positive ion and multiple reaction monitoring mode.The detection limits of morphine,O6‑Monoacetylmorphine,heroin,codeine,cocaine,methamphetamine,ketamine,methadone,and dolantin were 100,50,50,100,20,20,10,1,and 0.01 ng/mL,respectively.The practical cases contained methamphetamine,codeine,cocaine,and O6‑monoacetylmorphine were detected accurately and rapidly.The method has the advantages of high sensitivity and good accuracy.The sample processing is simple and can be analyzed in a short time.This method is suitable for the analysis of morphine,O6‑monoacetylmorphine,heroin,codeine,cocaine,methamphetamine,ketamine,methadone,and dolantin in some practical cases.

Amino acid identification and sequence analysis of peptides by reaction mass spectrometry

Fast atom bombardment mass spectrometry (FAB-MS) is applied to distinguish N- terminal series ions from C-terminal series ions of a peptide by on-probe acetylation, it provides valuable information about the sequence of an unknown peptide. The FAB mass spectra contain a number of characteristic ions at low-mass region in addition to the sequence ions at high-mass region. It was found that the ions below m/z 200 are characteristic of the amino acid composition of the peptide, from which the amino acid composition of the peptide could be estimated. Additionally, mixture analysis is also discussed.

Intensification of bituminous coal and lignite oxidation by copper-based activating additives

The oxidation of lignite and bituminous coal samples modified by 5 wt%(in terms of dry salt)addition of copper salts Cu(NO_(3))_(2),CuSO_(4),and Cu(CH_(3)COO)_(2) was studied.The samples’reactivity was studied by thermogravimetry within a temperature range of 45–600℃ at a heating rate of 2.5℃/min in an oxidizing environment.The introduction of activating additives has resulted in a significant decrease in the temperature of intense oxidation onset(ΔT_(i)=20/94℃),in a reduction in the sample residence time in the volatile matter release region(Δt_(e)=2/22 min)and the total duration of the coal combustible mass oxidation(Δt_(f)=8/14 min).The Friedman method was used to calculate the activation energy values for the oxidation process of the modified samples.The maximum change in activation energy values was observed for the bituminous coal sample.The possible mechanism behind the action of the copper-salt additives,which activate the oxidation of lignite and bituminous coal,is discussed.According to the data of mass spectrometric analysis,the concentration of NOx in the reaction products decreases as the temperature of the activated oxidation process is shifted towards the low-temperature region.

1-(3-Aminopropyl)-3-butylimidazolium bromide for carboxyl group derivatization:potential applications in high sensitivity peptide identification by mass spectrometry

The cationic reagent 1-(3-aminopropyl)-3-butylimidazolium bromide(BAPI) was exploited for the derivatization of carboxyl groups on peptides.Nearly 100% derivatization efficiency was achieved with the synthetic peptide RVYVHPI(RI-7).Furthermore,the peptide derivative was stable in a 0.1% TFA/water solution or a 0.1%(v/v) TFA/acetonitrile/water solution for at least one week.The effect of BAPI derivatization on the ionization of the peptide RI-7 was further investigated,and the detection sensitivity was improved >42-fold via matrix-assisted laser desorption/ionization time-of-flight mass spectrometry(MALDI-TOF MS),thus outperforming the commercial piperazine derivatization approach.Moreover,the charge states of the peptide were largely increased via BAPI derivatization by electrospray ionization(ESI) MS.The results indicate the potential merits of BAPI derivatization for high sensitivity peptide analysis by MS.

A quick and effective multivariate statistical strategy for imaging mass spectrometry

A new multivariate statistical strategy for analyzing large datasets that are produced by imaging mass spectrometry（IMS） techniques is reported.The strategy divides the whole datacube of the sample into several subsets and analyses them one by one to obtain the results.Instead of analyzing the whole datacube at one time,the strategy makes the analysis easier and decreases the computation time greatly.In this report,the IMS data are produced by the air flow-assisted ionization IMS（AFAI-IMS）.The strategy can be used in combination with most multivariate statistical analysis methods.In this paper,the strategy was combined with the principal component analysis（PCA） and partial least square analysis（PLS）.It was proven to be effective by analyzing the handwriting sample.By using the strategy,the m/z corresponding to the specific lipids in rat brain tissue were distinguished successfully.Moreover the analysis time grew linearly instead of exponentially as the size of sample increased.The strategy developed in this study has enormous potential for searching for the mjz of potential biomarkers quickly and effectively.

Nontargeted identification of peptides and disinfection byproducts in water

A broad range of organic compounds are known to exist in drinking water sources and serve as precursors of disinfection byproducts（DBPs）.Epidemiological findings of an association of increased risk of bladder cancer with the consumption of chlorinated water has resulted in health concerns about DBPs.Peptides are thought to be an important category of DBP precursors in water.However,little is known about the actual presence of peptides and their DBPs in drinking water because of their high sample complexity and low concentrations.To address this challenge and identify peptides and non-chlorinated/chlorinated peptide DBPs from large sets of organic compounds in water,we developed a novel high throughput analysis strategy,which integrated multiple solid phase extraction（SPE）,high performance liquid chromatography（HPLC）separation,and non-target identification using precursor ion exclusion（PIE）high resolution mass spectrometry（MS）.After MS analysis,structures of candidate compounds,particularly peptides,were obtained by searching against the Human Metabolome Database（HMDB）.Using this strategy,we successfully detected 625 peptides（out of 17,205 putative compounds）and 617 peptides（out of 13,297）respectively in source and finished water samples.The source and finished water samples had 501 peptides and amino acids in common.The remaining 116 peptides and amino acids were unique to the finished water.From a subset of 30 putative compounds for which standards were available,25 were confirmed using HPLC-MS analysis.By analyzing the peptides identified in source and finished water,we successfully confirmed three disinfection reaction pathways that convert peptides into toxic DBPs.

A new technique helps to uncover unknown peptides and disinfection by-products in water

Environmental water samples can be extremely complex,with potentially thousands of molecules that can derive from natural organic matter（NOM）and thousands that derive from anthropogenic contaminants.As complex as these samples are,drinking water can be even more complex.Due to disinfectants that are used to treat drinking water（e.g.,chlorine,chloramines,