Rapid determination of L-ascorbic acid content in vitamin C serums by ultra-high-performance liquid chromatography-tandem mass spectrometry.

Objective: This study aimed to develop and validate a rapid, simple, accurate and precise analytical method for the quantification of L-AA in vitamin C serums. Moreover, the developed method was further applied to determine L-AA in eight different brands of vitamin C serums. A complementary study was also carried out to evaluate the stability of L-AA in the vitamin C serum samples after 15, 30, 45 and 60 days of storage at ambient temperature (15-35°C).

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.

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.