Solubility and stability of sterigmatocystin in aqueous solutions.

In the present work we studied the ability of phosphate buffer to solubize sterigmatocystin (ST) at different pH values. We observed a higher solubility of ST at acid pH values, specially in pH 4.5. The ST adsorbed to glass was maximum at alkaline pH values.Also we studied the stability of different concentrations of ST in phosphate buffer at different pH values. After 24 h, ST can be considered stable at alkaline, neutral and 3.5 pH values. At pH 4.5, 5.5 and 6.5, ST recovered after 24 h was lower, specially at pH 4.5, when only 44% was recovered. At day 7, ST was stable only at pH 7.5 (91%). The lowest recovery was at pH 4.5 (25%).