Separação e purificação do ácido clavulânico através de extração líquido-líquido seguida de adsorção em coluna de leito fixo.
Resumen
A study was made of the extraction of clavulanic acid (CA) from a fermented medium and
its concentration and purification, based on a comparison of two liquid-liquid extraction
methods, followed by adsorption in a fixed bed column containing resins (hydrophobic
polymeric resin and ion exchange resin). The extraction and adsorption steps proposed
here were evaluated from the standpoint of Yield (Y), purification factor (PF) and
concentration factor (CF). The extractions were carried out with the organic solvents ethyl
acetate, butyl acetate, 2-butanol, n-butanol and methyl isobutyl ketone. These extractions
were carried out at ambient temperature, pH values of 2.0, 3.0, 4.0 and 5.0 and with
different volume ratios of aqueous phase and organic phase (VAF/VOP). After extraction
with the organic solvent, the solution was reextracted with a phosphate buffer solution.
Extractions were also done with two-phase aqueous systems (TPAS) composed of
polyethylene glycol (PEG) and phosphate. The experimental conditions were: ambient
temperature, pH of 6.0 and 7.0, and different molecular weights of PEG (400, 600, 4000).
For the extractions involving organic solvents, an evaluation was made of the purification
of clavulanic acid by ion exchange adsorption with Amberlite IRA-400 resin in a fixed bed
column at a temperature of 10°C and pH 6.2. After adsorption by ion exchange, the column
was washed with Milli-Q water and the elution was studied with different compositions of
a solution composed of NaCl 5% (p/v) and Tris-HCl. The elution was carried out at pH 6.2
and a feed flow of approximately 6 mL.min-1. The solution eluted from the ion exchange
was fed into a column filled with Amberlite XAD-4 resin at a temperature of 10°C and pH
of 6.2. For the TPAS extractions, the application of ion exchange and nonspecific
adsorption with Amberlite XAD-4 resin for the separation of CA from PEG was evaluated
separately.