João Rodrigo Santos

Learn More
Characterisation of coffee quality based on bean quality assessment is associated with the relative amount of defective beans among non-defective beans. It is therefore important to develop a methodology capable of identifying the presence of defective beans that enables a fast assessment of coffee grade and that can become an analytical tool to standardise(More)
The analysis of E-2-nonenal is of considerable interest for the brewery industry as this compound is claimed to be responsible for a paper/cardboard unpleasant flavour. Usually, the presence of E-2-nonenal can be noticed in aged beers at levels higher than 0.1 microg/l. In this work, an analytical method was developed to determine E-2-nonenal in beer(More)
The objective of this study is to analyze the potential of TERRA SAR-X dual images, on the StripMap mode, for classification of forest cover and of land use classes resulting from human activities. The area under study is located in the portions of SW Brazilian Amazon region, Acre State. The StripMap images of TerraSAR-X, dual polarization, were processed(More)
The estimation of the time since death known as postmortem interval (PMI) is a main issue in the field of forensic science and legal medicine. In this work it is proposed a sequential injection system for the determination of hypoxanthine and potassium in the same sample of vitreous humor since the concentrations of both parameters change with PMI and the(More)
A tubular bismuth film electrode (BFE), installed as part of a multisyringe flow injection system, was used as an amperometric detector to determine the concentration of diclofenac sodium in pharmaceutical formulations. A tubular voltammetric detection cell was employed, in which the hydrodynamic flow conditions were not disturbed. This automated method(More)
In this work, the coupling of a commercial monolithic column to a traditional low pressure FIA system is proposed for the analysis of theobromine, theophylline and caffeine in coffee brewed samples using UV detection. The parameters mobile phase composition, flow rate and loop volume were evaluated and discussed considering the various chromatographic(More)
A standard addition method was implemented by using a flow manifold able to perform automatically multiple standard additions and in-line sample treatment. This analytical strategy was based on the in-line mixing of sample and standard addition solutions, using a merging zone approach. The flow system aimed to exploit the standard addition method to(More)
In this work, a real-time and in-situ analytical tool based on near infrared spectroscopy is proposed to predict two of the most relevant coffee parameters during the roasting process, sucrose and colour. The methodology was developed taking in consideration different coffee varieties (Arabica and Robusta), coffee origins (Brazil, East-Timor, India and(More)
In this work, a total flow analysis system based on a novel solid-liquid extraction chamber is presented. This strategy enables all the main experimental procedures for the analysis of a solid sample to be performed automatically: enrichment of the liquid extract, sample treatment, filtration of the liquid extract from the solid sample, directing the(More)
A method for the simultaneous determination of E-2-nonenal and beta-damascenone in beer by reversed-phase liquid chromatography using UV detection is presented. The method consists of beer steam distillation, followed by an extraction/concentration step using Sep-Pak Plus C18 RP cartridges and determination by HPLC at 226 nm UV-absorption maximum. The(More)