Capillary electrophoresis (CE): a powerful tool to characterize humic acid (HA)

Abstract

Neste estudo, avaliou-se a possibilidade de eliminação das etapas de purificação envolvidas na caracterização de HA. HA de diferentes fontes foram analisados por CZE apresentando diferentes eletroferogramas. Essas diferenças observadas mostram que a caracterização do HA por CZE depende da carga e do tamanho do HA. Os resultados apresentados neste trabalho sugerem que não é necessária a purificação da amostra para a caracterização de HA por CZE. Baseados nos resultados, a CZE mostrou-se uma ferramenta promissora para caracterização de HA de diferentes origens sem a etapa de purificação da amostra.The present study evaluates the possibility of eliminating the purification steps involved in the characterization of HA by capillary zone electrophoresis (CZE). The HAs of various sources were analyzed, showing different electropherograms by CZE, which depend on the charge and size of HA. The data suggest that the purification of the sample is not necessary to characterize HAs. Based on the results, CZE showed to be a promising tool to characterize HA of different origins without the purification step of the sample. Keywords: humic acid, characterization, capillary zone electrophoresis IntroductionHumic substances (HS) have an important role in the environment. They are related to the fertility of the soils, contributing to the increasing the harvest production. 1,2 In soil, HS are implicated in water-holding capacity, pH buffering, ion exchange, binding of metal ions and hydrophobic compounds. [3][4][5][6] These substances are classified into three groups, humic acids (HAs), fulvic acids (FAs) and humins, on the basis of their solubility in acidic and basic solutions. [7][8][9] HAs present relatively high molecular mass polyelectrolytes containing aromatic, aliphatic and heterocyclic subunits.10 Their chemical structure is less known due to the origin and the natural conditions prevailing during their formation. 11 The degree of ionization of these macromolecules is governed by the amount of ionized phenolic and carboxylic groups of HAs, which is a function of solution pH. 12-14As a modern analytical technique, capillary electrophoresis (CE) has become an attractive method for the characterization of molecules with high structural complexity and wide range of molecular weights, such as HA. [15][16][17][18] The CE, as a method of characterizing a variety of HS, is suitable due to its polyelectrolyte properties, reflecting its charge-to-mass ratio. [19][20][21][22][23][24][25][26] The characterization of humic compounds provides important information for the evaluation of their capacity of interaction with metal ions and different classes of organic compounds as pesticides. 25Some valuable features of this analytical technique are short analysis time, selectivity for the analytes, simple analytical procedure, and micro-quantity consumption of samples. In CZE, the introduction of samples is carried out at the anode, while the detection is realized at the cathode. Ionic species are separated based on their charge and si...

Capillary electrophoresis profiles and fluorophore components of humic acids in Nebraska corn and Philippine rice soils

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Application of Humic Acid and Sulphur on the Vigour and Viability of Harvested Soybean Seeds with Active Compounds

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Application of multiplex methylated‐specific PCR with capillary electrophoresis to explore prognostic value of TSGs hypermethylation for hepatocellular carcinoma

“…Compared with conventional MSP, the improved approach can amplify multiple regions of the template in one reaction tube with several pairs of primers, thus saving a large amount of time, labor, and template for the experiment. Furthermore, multiplex PCR products detection is coupled with capillary electrophoresis (CE), which has become an attractive separation method because of its excellent advantages including fast‐separation, high‐resolution, and less sample consumption, thus giving rise to notable savings of labor and reagent costs, and errors from sample pretreatment steps can also be avoided . Thus, this study aimed to provide a more sensitive and efficient detection method for screening and making prognosis prediction for liver cancer.…”