This paper describes the monitoring of ethyl carbamate concentration in sugar cane spirit from industrial distilleries in Brazil. In total, 18 distilleries from Minas Gerais and São Paulo states were evaluated, with, a total of 336 samples from August 2017 to August 2019. The ethyl carbamate was analyzed using a previously validated mass spectrometric method. Analytical curves presented coefficient of determination (R2) values higher than 0.99, and quality control samples showed a relative standard deviation (RSD) below 9%. Concentrations of ethyl carbamate ranged from not detected to 1608 µg L-1, with mean values of 294.2, 280.7 and 230.0 µg L-1 in 2017, 2018, and 2019, respectively. On average, 46, 44 and 69% of samples presented levels of ethyl carbamate below 210 µg L-1. A variety of factors may have led to distillery A having a low level (ca. 115 µg L-1) of ethyl carbamate, including controlled temperature, yeast strain, post-harvesting quality, sugar cane variety choice, and the treatment process on the sugar cane juice, which goes towards the addition of Ca(OH)2, heating and freezing. These results showed the importance of internal quality control, and that sugar cane juice treatment may be a way to decrease ethyl carbamate in the distilleries.

A new bis-iridoid glucoside minutifloroside (1) was isolated from Palicourea minutiflora, together with asperuloside, (-)-epicatechin, catechin, quercetin, rutin, ursolic acid, oleanolic acid, daucosterol and two monoterpenic indole alkaloids strictosidinic acid and vincosamine. Structural characterization of the compounds was established on their spectral data basis, mainly mass spectrometry (MS) and 1D and 2D nuclear magnetic resonance (NMR). The bis-iridoid showed high activity against Candida albicans strain and antioxidant activity.

This work reports the theoretical and experimental study of fragmentation reactions in the gas phase of five phenolic acids using triple quadrupole mass spectrometry by electrospray ionization in negative ionic mode, as well as the isotope exchange experiments. MS/MS spectra were analyzed to suggest the fragmentation mechanisms, while theoretical calculations at the theory level B3LYP/6-311+G** were performed to expose the proposed mechanisms viability for this class of compounds. As expected, compounds with aromatic methoxy substitution presented •CH3 radical elimination as the principal fragmentation pathway, forming dystonic ions. Compounds without methoxy substituents dissociate with higher energies losing the CO2, CO and H2O. The isotopic marking experiments indicated the exchange of hydrogens by deuterases in the hydroxyl protons, which corroborates with the proposed mechanisms.

Vegetable oil analyses, especially due to the complexity of the oil components, are commonly laborious, requiring several analytical techniques. In this work, electrospray ionization mass spectrometry with direct injection (DIMS), along with 18-crown-6 ether (crown ether) chelating agent and trifluoroacetic acid (TFA), was used to characterize and semi-quantitatively evaluate commercial vegetable oils. As a result, an unprecedented DIMS method of triacylglycerols (TAGs) analysis for semi-quantitative profiling of fatty acids in commercial oils (e.g., soybean, sunflower, corn, oil, canola), without sample derivatization, was developed. The results of the ion abundances related to the analyzed TAGs, with quantitative percentage analyzed by gas chromatography with flame ionization detector (GC-FID), allowed generating correction factors for each oil. DIMS analysis with crown ether/TFA resulted in the elimination of isobaric interferences from sodium and potassium adducts, facilitating the ion assignments, due to the one-ion-per-molecule observation in the mass spectrum. Chemometric analyses by principal component analysis (PCA) and heatmap, to evaluate the ionic profile of the oils, grouped them accordingly to their TAG content. Olive oil was identified as the most different from the other oils. Overall, a semi-quantitative approach to investigate the vegetable oils, reaching low percentage variation for DIMS, with 2 min analyses and 30 min sample preparation, was proposed.

The objective was identifying three different anthocyanidins and to quantify them in six different berries. Results from the conventional method (using extraction with hydrochloric acid) were compared with data from the proposed method (without acid extraction). The following figures of merit were used: linearity, accuracy, linear range, limits of detection and quantification, using an ultra performance liquid chromatography (UPLC) coupled to a triple quadrupole mass spectrometer equipped with an electrospray ionization source. The separation of anthocyanidins can be achieved in a much smaller period of time (1.30 min) and the cyanidin from Morus nigra L., Rubus idaeus L. and Vaccinium myrtillus L. was found in higher amounts in extracts obtained from the proposed method. Proposed mechanisms of mass spectrometry (MS/MS) collisional induced dissociation for pelargonidin, cyanidin and delphinidin were obtained and this is the first time that concentrations of anthocyanidins present in fruits of Solanum americanum Mill. were reported.

Chemical investigation of Sinningia warmingii (Gesneriaceae) tubers lead to the isolation of two new dimeric naphthoquinone derivatives, named warmingiins A and B, besides six known compounds, aggregatin E, aggregatin F, tectoquinone, halleridone, cleroindicin B, and cornoside. All compounds were identified by spectroscopic analysis, mainly nuclear magnetic resonance (NMR) and mass spectrometry (MS), and comparison with the literature. The structure of the warmingiin A, which is an artifact of warmingiin B, was confirmed by X-ray diffraction analysis. Antimicrobial activity of the ethanolic extract and fractions of S. warmingii was evaluated against Staphylococcus aureus, S. epidermidis, Escherichia coli, Pseudomonas aeruginosa, Candida albicans, C. dubliniensis, C. glabrata and C. parapsilosis. All samples were inactive.