The development and illustrative applications of an ambient ionization technique termed Venturi easy ambient sonic-spray ionization (V-EASI) is described. Its dual mode of operation with Venturi self-pumping makes V-EASI applicable to the direct mass spectrometric analysis of both liquid (V(L)-EASI) and solid (V(S)-EASI) samples. V-EASI is simple and easy to assemble, operating solely via the assistance of a sonic stream of nitrogen or air. The sonic gas stream causes two beneficial and integrated effects: (a) the self-pumping of solutions via the Venturi effect and (b) sonic-spray ionization (SSI) of analytes either in solution or resting on solid surfaces. In its liquid mode, V(L)-EASI is applicable to analytes in solution, forming negatively and/or positively charged intact molecular species in a soft fashion with little or no fragmentation. In its solid mode, V(S)-EASI relies on Venturi self-pumping of a proper SSI solvent solution in combination with SSI to form a stream of bipolar charged droplets that bombard the sample surface, causing desorption and ionization of the analyte molecules. As for its precursor technique (EASI), V-EASI generates bipolar droplets with considerably lower average charging, which increases selectivity for ionization with high signal-to-noise ratios and clean spectra dominated by single molecular species with minimal solvent ions. V-EASI also operates in a voltage-, heat-, and radiation-free fashion and is therefore free of thermal, electrical, or discharge interferences.

Antimicrobial bacterial cellulose-silver nanoparticles composite membranes have been obtained by“in situ”preparation of Ag nanoparticles from hydrolytic decomposition of silver nitrate solution using triethanolamine as reducing and complexing agent. The formation of silver nanoparticles was evidenced by the X-ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and absorption in the UV-Visible (350 nm to 600 nm). Thermal and mechanical properties together with swelling behavior for water were considered. TEA concentration was observed to be important in order to obtain only Ag particles and not a mixture of silver oxides. It was also observed to control particle size and amount of silver contents in bacterial cellulose. The composite membranes exhibited strong antimicrobial activity against Gram-negative and Gram-positive bacteria.

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A novel strategy for the ESI-MS monitoring of reaction solutions involving the alternate use of permanently charge-tagged reagents has been used for comprehensive mass spectrometry monitoring of the multicomponent Hantzsch 1,4-dihydropyridine reaction. By placing a charge tag on either, or both, of the two key reactants, ion suppression effects for ESI were eliminated or minimized, and comprehensive detection of charge-tagged intermediates was achieved. The strategy allowed the trapping and characterization of the important intermediates in the mechanism for 1,4-dihydropyridine formation.

Venturi easy ambient sonic-spray ionization mass spectrometry working in the liquid mode (VL-EASI-MS) is shown to provide rapid and reliable characterization of crude oil distillates. With no extraction or pretreatments, samples of gasoline, kerosene, diesel, and admixtures of gasoline/diesel and gasoline/kerosene were directly analyzed by VL-EASI(+)-MS. Homologous series of natural N-heteroaromatics were detected in their protonated forms providing typical profiles of polar markers. For gasoline, VL-EASI(+)-MS detects a homologous series of mainly C1–C5 alkyl pyridines. For kerosene, a typical series of alkylated tetrahydroquinolines is detected. For diesel, the V-EASI(+)-MS profile is much richer because of the detection of several classes of many N-heteroaromatics. VL-EASI(+)-MS is also shown to provide typical spectra for petrochemical gasolines detecting specific antioxidants. Admixtures of gasoline/kerosene and gasoline/diesel are also clearly characterized with limits of detection of 10 and 1% (v/v), respectively. Fourier transform-ion cyclotron resonance mass spectrometry (FT-ICR MS) has been used to confirm assignments of the polar markers detected by VL-EASI(+)-MS.

Solutions of aza-Morita-Baylis-Hillman (aza-MBH) reactions were directly monitored by ESI(+)-MS(/MS) spectrometry to obtain information on their mechanism. A unique bis-sulfonamide intermediate was intercepted and characterized and, based on this novel species, a mechanism that rationalizes the uniqueness of aza-MBH reactions is proposed.

Endometriosis is a chronic gynecological condition that affects 10-32% of women of reproductive age and may lead to infertility. The study of protein profiles in follicular fluid may assist in elucidating possible biomarkers related to this disease. For this, follicular fluid samples were obtained from women with tubal factor or minimal male factor infertility who had pregnancy outcomes after in vitro fertilization (IVF) treatment (control group, n = 10), women with endometriosis (endometriosis group, n = 10), along with the endometrioma from these same patients were included (endometrioma group, n = 10). For proteomic analysis, samples were pooled according to their respective groups and normalized to protein content. Proteins were analyzed by in tandem mass spectrometry (MS(E)) Spectra processing and the ProteinLynx Global Server v.2.5. was used for database searching. Data was submitted to the biological network analysis using Cytoscape 2.8.2 with ClueGO plugin. As a result, 535 proteins were identified among all groups. The control group differentially or uniquely expressed 33 (6%) proteins and equal expression of 98 (18%) proteins was observed in the control and endometriosis groups of which 41 (7%) proteins were further identified and/or quantified. Six (1%) proteins were observed in both the endometriosis and endometrioma groups, but 212 (39%) proteins were exclusively identified and/or quantified in the endometrioma group. There were 9 (1%) proteins observed in both the control and endometrioma groups and there were 139 (25%) proteins common among all three groups. Distinct differences among the protein profiles in the follicular fluid of patients included in this study were found, identifying proteins related to the disease progression and IVF success. Thus, some pathways related to endometriosis are associated with the presence of specific proteins, as well as the absence of others. This study provides a first step to the development of more sensitive diagnostic tests and treatment.

Purpose This research proposed to study the changes in lipid composition in cumulus cells (CCs) from women who achieved pregnancy compared with women who did not, after in vitro fertilization treatment. This approach has the potential to provide novel information on the lipid metabolism of the CCs and as an additional method to predict pregnancy. Method Fifty-four samples from couples with tubal and male factor infertility and where the female partner was age 35 or younger were divided in two groups according to their level of hCG 14 days after embryo transfer as follows: (1) 23 samples in pregnant group and (2) 31 samples in non-pregnant group. Lipid extraction was performed by the Bligh-Dyer protocol, and lipid profiles were obtained by MALDI-TOF MS. Mass spectra data were processed with MassLynx, and statistical analysis was performed using MarkerLynx extended statistic. OPLS-DA model was built. Results S-plot Analysis revealed three ions as potential markers in the pregnant group, and five ions in the nonpregnant group. These ions were identified in the human metabolome database (HMDB) as phosphatidylcholine in the pregnant group and as phosphatidylethanolamine, phosphatidylserine and phosphatidylinositol species in the non-pregnant group. These lipids might be involved in cell proliferation and differentiation, apoptosis and GAP junction regulation. Conclusion We conclude that MALDI-TOF MS can be used as an informative and fast analytical strategy to obtain and study the lipid profile of cumulus cells and can potentially be used as a supporting tool to predict pregnancy based on the metabolic state of the CCs.