Publications by authors named "Jose C Penteado"
Since "omics" techniques emerged, plant studies, from biochemistry to ecology, have become more comprehensive. Plant proteomics and metabolomics enable the construction of databases that, with the help of genomics and informatics, show the data obtained as a system. Thus, all the constituents of the system can be seen with their interactions in both space and time.
View Article and Find Full Text PDFDetermination of organic acids in intracellular extracts and in the cultivation media of marine microalgae aid investigations about metabolic routes related to assimilation of atmospheric carbon by these organisms, which are known by their role in the carbon dioxide sink. The separation of these acids was investigated by hydrophilic interaction liquid chromatography (HILIC) using isocratic elution with a mobile phase composed of 70:30 v/v acetonitrile/20 mmol/L ammonium acetate buffer (pH 6.8) and detection at 220 nm.
View Article and Find Full Text PDFFluorimetric determination of intra- and extracellular free amino acids in the microalgae Tetraselmis gracilis (Prasinophyceae) using monolithic column in reversed phase mode.
J Sep Sci
August 2009
Article Synopsis
- The paper details the creation and use of a reversed-phase high-performance liquid chromatography (RP HPLC) method utilizing a C(18) monolithic stationary phase for analyzing amino acids in the marine alga Tetraselmis gracilis.
- The method successfully separated and quantified 19 amino acids in about 39 minutes while achieving a resolution greater than 1.5, using a binary gradient elution with fluorimetric detection.
- Significant findings include the identification of key intracellular amino acids during the exponential growth phase and notable excretion of valine, alanine, serine, and glycine into the surrounding media, highlighting the efficiency and cost-effectiveness of the monolithic phase in HPLC.
Article Synopsis
- The study developed a cost-effective automated method for detecting amino acids using sequential injection chromatography (SIC) with fluorimetric measurement after pre-column derivatization.
- The chromatography process involved five isocratic elution steps with specific solvent mixtures and successfully separated various amino acids with acceptable resolution within a cycle time of 25 minutes, which could be reduced to 10 minutes at a higher flow rate.
- The method was effectively applied to analyze intracellular free amino acids in the green alga Tetraselmis gracilis, showing good recovery rates of spiked amino acids.
Adsorption and desorption properties of atrazine and some of its metabolites, hydroxyatrazine (AT-OH), deethylatrazine (DEA), and deisopropylatrazine (DIA), were studied with a clay-rich soil sample (clay content of 53%). A part of this soil was treated with humic acid (Soil-HA) to assess the influence of this important component of natural organic matter on adsorption and desorption processes. This study was performed using the batch approach with 1.
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