Effect Of Enzymatic Hydrolysis On Arsenic Speciation In Perna Viridis

The Alcalase AF2.4L and trypisn were used to hydrolyze the proteins of Pernaviridis as a method of sample pre-treatment for the determination of arsenic speciation.Arsenic speciations were examined by HPLC-ICP-MS, and the unknown compounds ofarsenic were determined by ESI-MS/MS.The main results include:1)The condition of enzymic hydrolysis was studied with the degree hydrolysis as ameasured indicator. PH, temperature and hydrolysis duration were investigated. Theoptimum condition was: Alcalase AF2.4L s/l=1:10， enzyme=2%， pH=9.0，Temperature=55℃, time=4h; Trypsin s/l=1:10, enzyme=1.5%， pH=8，Temperature=37℃，time=2h;2) A column of Hamiltion PRP X100with a gradient program could separate sixcommon arsenic compounds. And the detect limit was0.3-1.0ng/g，RSD<5%；3）The extraction rate of Alcalase and Trypsin are103.59%and98.21%，both higherthan without enzymatic(88.26%).4) The two unknown arsenic compounds were investigated by ESI-MS/MS. One ofthem was proved to be DMAE, and the other one need to be further studied.The results suggest enzymatic hydrolysis could be used as a pre-treatment method toimprove the extraction efficiency.