Evaluation of the QuEChERS method for the determination of phenolic compounds in yellow (Brassica alba), brown (Brassica juncea), and black (Brassica nigra) mustard seeds.

Studies about the phenolic composition of yellow (Brassica alba), brown (Brassica juncea), and black (Brassica nigra) mustard seeds are still scarce in the literature. Hence, this study describes, for the first time, the use of the QuEChERS extraction method followed by UHPLC-MS/MS analysis for phenolic compound determination in the seeds of these mustard species. Under the optimized extraction and analysis conditions, twenty-one phenolic compounds were evaluated. Six, eleven, and seven were found in B. alba, B. juncea, and B. nigra seeds, respectively. The most abundant phenolic compound was sinapic acid, which was found in amounts ranging from 44 to 82 times higher than the other major compounds found in the mustard seeds, ferulic, 4-hydroxybenzoic and protocatechuic acids. Overall, these results are an important contribution to the characterization of the phenolic composition of the three in natura mustard seeds species, and support future reliable phenolic compounds determination with the QuEChERS method.

Rapid extraction method followed by a d-SPE clean-up step for determination of phenolic composition and antioxidant and antiproliferative activities from berry fruits.

Despite the numerous studies that have shown a wide range of biological activities to berry fruits, scientific data focusing on modern, rapid and simple extraction methods followed by a clean-up step is still lacking. Therefore, the present work was aimed at investigating the use of a fast one-step solid-liquid extraction procedure followed by a dispersive solid-phase extraction (d-SPE) clean-up step to evaluate the phenolic composition, antioxidant and antiproliferative activities from three of the principal berries found in Brazil, pomegranate (Punica granatum L.), blackberry (Rubus ulmifolius Schott.), and strawberry (Fragaria × ananassa Duch.). Under the optimized extraction conditions, sixteen phenolic compounds were determined by UHPLC-MS/MS analysis and all berry extracts showed antioxidant activity and antiproliferative effects on cervical (HeLa) and colon (HT-29) cancer cells. Overall, these results highlight the importance of the clean-up step for more reliable data in studies of health-promoting proprieties from berry fruits.

Determination of acrylamide in brewed coffee by dispersive liquid-liquid microextraction (DLLME) and ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS).

This work has proposed the application of optimized dispersive liquid-liquid microextraction (DLLME) in order to extract acrylamide from brewed coffee samples for its subsequent determination by ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). DLLME achieved superior results employing 300 µL of brewed coffee, 100 µL of dichloromethane, 400 µL of acetonitrile and without sodium chloride addition. Quantitative analyses were carried out by the standard addition method, and the limits of detection and quantification were 0.9 and 3.0 µg L-1, respectively. Recoveries ranged from 97 to 106%, and the intra- and inter-assay precisions ranged from 6 to 9%. The proposed analytical method was applied to seventeen brewed coffee samples prepared in a filter coffee maker, and acrylamide amounts varied from 10.5 to 28.5 µg L-1. Therefore, the suggested DLLME-UPLC-MS/MS method is promising for routine analysis in order to guarantee the quality control of acrylamide in brewed coffee.