title: Evaluation of ion exchange resins and various enzymes in thiamine analysis.
abstract: Four ion exchange resins and 9 enzyme preparations are evaluated for use in the official AOAC thiamine method because Decalso and Clarase or Mylase P either are no longer available or are available in a form that is not suitable for use in the assay. The enzymes are prepared in the same manner described for Clarase or Mylase P in the AOAC method and are compared with Clarase T300 for their effectiveness in releasing thiamine from thiamine phosphate, and their ability to produce similar results on samples. Rhozyme S is 90-100% as effective as Clarase T300 in both of these respects. The other enzymes tested were not satisfactory. Further study is necessary because Rhozyme S also is no longer manufactured. The ion exchange resins are prepared for use in the manner described for Decalso in the AOAC method. Recoveries of thiamine range from 95 to 100%, using Bio-Rex 70 (hydrogen form) ion exchange resin. The other resins tested were not satisfactory.
mesh_terms: D004798:Enzymes; D005504:Food Analysis; D007202:Indicators and Reagents; D007475:Ion Exchange Resins; D013831:Thiamine / Q000032:analysis*
chemical_list: D004798:Enzymes; D007202:Indicators and Reagents; D007475:Ion Exchange Resins; D013831:Thiamine