Detección por cromatografía en capa fina de algunos antioxidantes comunes

A method is described for the qualitative determination of butylated hydroxyanisole, butylated hidroxytoluene, propyl gallate, octyl gallate and dodecyl gallate in edible fats and oils. The method is based on the development of a specific colour derived from the reaction of the antioxidants with N,N-dimethyl-p-phenylenediamine in the presence of a mild oxidizing agent in alkaline solution. The method gave good results and can be carried out easily with facilities existing in most analytical laboratories.Se describe un método para la determinación cualitativa de 3-t-butil-4-hidroxianisol, 2,6-di-t-butil-4-hidroxitolueno, galato de propilo, galato de octilo y galato de dodecilo en aceites y grasas comestibles. El método está basado en el desarrollo de un derivado coloreado específico a partir de la reacción de los antioxidantes con la N,N-dimetil-p-fenilenediamina en presencia de agente oxidante suave en solución alcalina. El método dio buenos resultados y puede llevarse a cabo fácilmente con los medios existentes en la mayoría de los laboratorios analíticos

Lipid levels in cabbage leaves (Brassica oleracea)

Cabbage (Brassica oleracea L, var Glory) is one of the cruciferous vegetables. The objective of this study was to investigate the neutral, glyco‐ and phospholipids of cabbage and their fatty acid composition. Lipids from its leaves were extracted and fractionated into neutral lipids, glycolipids and phospholipids. The fatty acids of each fraction were analysed by gas liquid chromatography. Copyright © 1990 John Wiley & Sons, Lt

Composition of the essential oil of marjoram (Origanum majorana L.)

The quantitative composition of the essential oil of Origanum majorana L. grown in Greece is reported. A total of 45 compounds were identified by means of gas liquid chromatography and GC-MS analysis. The most prominent component was 4-terpineol (37%) and three substances were identified for the first time in marjoram oils. © 1992

Development and Validation of Pesticide Residues Determination Method in Fruits and Vegetables through Liquid and Gas Chromatography Tandem Mass Spectrometry (LC-MS/MS and GC-MS/MS) Employing Modified QuEChERS Method and a Centrifugal Vacuum Concentrator

Pesticides are used for controlling organisms, weeds and animals, causing damage to plants. Although the use of pesticides is a prerequisite for producing safe food, their accumulation makes their rapid determination necessary to avoid negative impacts on human health. The aim of this study was to develop reliable and robust analytical methods for the determination of pesticide residues in fruits and vegetables, validated according to SANTE/12682/2019 guidance. Five different categories of fruits and vegetables were selected (apple, orange, onion, lettuce, tomato). The sample preparation was based on QuEChERS methodology, slightly modified in the clean-up step, and appropriate d-SPE reagents were selected for each commodity. A Multi-Tube Vortexer was used for better agitation. In the final step, the extract was split in two: one part was acidified and injected in LC-MS/MS and the other part was evaporated in a centrifugal vacuum concentrator, and reconstituted and injected in GC-MS/MS. With the centrifugal vacuum concentrator used instead of nitrogen stream, more pesticides were determined, while sensitivity and repeatability increased. Validation results satisfied the SANTE/12682/2019 guidelines for approximately 220 analytes for each commodity. LOQ was set at 0.010 mg/kg for all analytes. Successful external quality assessment (proficiency testing) proved that the methods are fit for purpose