Enzymatic hydrolysis of biological and environmental samples as pretreatment for analysis

Four commercially available proteases were tested, in conjunction with a lipase, for efficacy in hydrolyzing 3 tissue substrates: cod fillet, chicken egg, and bovine liver. Enzymatic hydrolysis of tissues minimizes the formation of emulsions during liquid-liquid extraction and does not accelerate the decomposition of acid- or base-labile analytes. Recovery of hexane and benzene phases from the hydrolysates was also evaluated. Protease from Streptomyces griseus combined with lipase from Candida cylindracea (available commercially) produced the highest percent hydrolysis (relative to classical acid hydrolysis) in all 3 tested tissues (60-95%) and the greatest recovery of hexane (100%) and benzene (92-100%) solvent phases.