The aqueous phase were acidified with sulfuric acid, taken to dryness and extracted with methanol (water soluble acidic fractions) and concentrated for TMS derivatives.

• 有机相(碱性和中性部分)经浓缩并硅烷化，水相经酸化、吹干、提取(提取物为酸性水溶性部分)并硅烷化。