Sequential Detection of Lipids, Metabolites, and Proteins in One Tissue for Improved Cancer Differentiation Accuracy.

Traditionally, molecular information on metabolites, lipids, and proteins is collected from separate individual tissue samples using different analytical approaches. Herein a novel strategy to minimize the potential material losses and the mismatch between metabolomics, lipidomics, and proteomics data has been demonstrated based on internal extractive electrospray ionization mass spectrometry (iEESI-MS). Sequential detection of lipids, metabolites, and proteins from the same tissue sample was achieved without sample reloading and hardware alteration to MS instrument by sequentially using extraction solutions with different chemical compositions. With respect to the individual compound class analysis, the sensitivity, specificity, and accuracy obtained with the integrative information on metabolites, lipids, and proteins from 57 samples of 13 patients for lung cancer prediction was substantially improved from 54.0%, 51.0%, and 76.0% to 100.0%, respectively. The established method is featured by low sample consumption (ca. 2.0 mg) and easy operation, which is important to minimize systematic errors in precision molecular diagnosis and systems biology studies.

Generating Supercharged Protein Ions for Breath Analysis by Extractive Electrospray Ionization Mass Spectrometry.

Supercharged protein ions produced by electrospray ionization are extremely efficient proton donors for secondary ionization. Here, by electrospraying the protein solutions containing 5% 1,2-butylene carbonate, the supercharged protein ions with unusually high proton density were produced as the primary ions for the ionization of exhaled breath samples in the extractive electrospray ionization mass spectrometry (EESI-MS), which resulted in the enhanced ionization efficiency for the breath analytes even with relatively low gas phase basicity. Moreover, the total number of metabolites detected in breath increased by about 260% in the mass range of 200-500 Da, owing to the substantial signal enhancement for breath metabolites, providing complementary and additional information to conventional SESI.

Single-Electron Oxidation/Alterable C3- and C10-Arylation of 9-MeO-phenanthrene.

A reactivity pattern for C3-arylation of 9-MeO-phenanthrene has been established for the first time by using 2-naphthyl amines as coupling partners. A series of phenanthrene- and naphthalene-based multifunctionalized polycyclic aromatic hydrocarbons have been obtained in good to excellent yields. Alternative C10-arylation of 9-MeO-phenanthrene has also been accomplished, using 2-naphthalenol derivatives as coupling partners. Trifluoroacetic acid is found crucial for the regioselectivity. Density functional theory calculations and electrochemical analyses have been performed to rationalize the reaction mechanism.

Fast quantification of fluoroquinolones in environmental water samples using molecularly imprinted polymers coupled with internal extractive electrospray ionization mass spectrometry.

In this study, a facile method based on molecularly imprinted polymers (MIPs) combined with internal extractive electrospray ionization tandem mass spectrometry (iEESI-MS/MS) was developed for the quantitative analysis of fluoroquinolones (FQs) in environmental water samples. FQ molecules in water samples were captured by the MIPs, which was retained on a 0.22 µm syringe filter. Then, an electrospray solution selected as the elution solution was employed to extract the FQs from the MIPs, getting an eluate of FQs for mass spectrometric interrogation. Under the optimized experimental conditions, low limits of detection (LODs, 0.015-0.026 µg L-1), with relative standard deviations (RSDs) less than 8.81% (n = 6) were obtained. The present method also provides good recoveries (91.14-103.60%) with acceptable precision (RSDs < 6.18%) and have no serious matrix effects for environmental water samples. The experimental results demonstrated that MIPs-iEESI-MS/MS has advantages including easy use, high speed (less than 3 min per sample) and high sensitivity for the analysis of FQs in environmental water samples, showing potential application in environmental science and water safety control.