Comparison of diode array and electrochemical detection in the C30 reverse phase HPLC analysis of algae carotenoids

Abstract

A determinação qualitativa e quantitativa de carotenóides pode fornecer diferentes e importantes informações sobre os organismos que os contêm. Na análise de pigmentos por HPLC diversos detectores podem ser utilizados, como diode array (DAD) e eletroquímico (ED). O presente trabalho tem como objetivo desenvolver um método por HPLC utilizando uma coluna C 30 para a identificação e quantificação de dezesseis pigmentos em diferentes classes de algas, além de comparar as respostas obtidas nos detectores DAD e ED por meio da análise dos resultados de precisão e exatidão. Apesar do ED ser geralmente um detector mais sensível que o DAD, os resultados de precisão e exatidão foram mais satisfatórios para o DAD. O método desenvolvido foi eficiente para a análise quantitativa dos pigmentos de cianobactérias e diferentes classes de algas, sendo que o padrão cromatográfico encontrado em cada classe foi discutido.Qualitative and quantitative determination of carotenoids pigments can provide valuable information about the organisms in which this important class of compounds is found. In the HPLC analysis of pigments, diode array (DAD), electrochemical (ED) and other kinds of detector may be used. The aim of this work is to develop an HPLC method using a C 30 column to identify and quantify sixteen different pigments from algae. A further aim is to compare precision and accuracy obtained by DAD and ED. ED is normally more sensible than DAD. On the other hand, the highest precision and accuracy was obtained with DAD. In conclusion, the method was efficient for quantitative and qualitative analyses of pigments from cyanobacteria and different microalgae classes. Their pigment patterns for several organisms are also discussed.

Seasonal changes in the pigment composition of natural population of Gracilaria domingensis (Gracilariales, Rhodophyta)

“…High light exposure requires seaweeds to acclimatize, avoiding inhibition of photosynthesis and degradation of the photosynthetic apparatus (Cabello-Pasini et al, 2000). Protection against the harmful effects of superexcitation by supersaturating light intensity is a fundamental survival mechanism of seaweeds in the intertidal zone (Häder et al, 2002;Andersson et al, 2006;Cardozo et al, 2006;Cardozo et al, 2008;Guaratini et al, 2009). On the other hand, during low photon flux conditions the algae have to harvest maximum light.…”

Antioxidant activity and chemical composition of the non polar fraction of Gracilaria domingensis (Kützing) Sonder ex Dickie and Gracilaria birdiae (Plastino & Oliveira)

“…The samples were prepared as previously published (Guaratini et al, 2009). In resume, the homogeneous, freeze-dried samples were weighed, dissolved in methanol:acetone (1:1, v:v) and sonicated for 15 min.…”

“…The analyses were carried out as previous reported (Guaratini et al, 2009). Chromatographic separations were carried out on a C 30 column (Ultracarb, 250 x 4.6 mm, 5 μm, Phenomenex) at 1.0 mL min -1 and room temperature, using as mobile phase: (A) methanol:water:1 M ammonium acetate buffer, pH 4.6 (90:8:2), and (B) methanol:methyl-tert-butyl ether (MTBE):1 M ammonium acetate buffer, pH 4.6 (30:68:2).…”

Improvement of the Extraction Process for High Commercial Value Pigments fromDesmodesmussp. Microalgae

“…4 Many carotenoids and xanthophylls have high commercial value, so there is a great interest in obtaining such substances directly from living organisms. Microalgae can provide pigments in an easy way, but is necessary finding the species that have the expected pigments and evaluate the best extraction method for these substances, in order to achieve high yields, using low-cost and toxicity solvents.…”