Modifications for the Methods of CE and Affinity LC Determination of Immunoglobulin G in Health-care Foodstuffs

Conventional methods of capillary electrophoretic and LC (with affinity column) determination of immunoglobulin G (IgG) in health-care foodstuffs were modified in 2 respects,① sample pretreatment was modified by precipitating casein with dilute acetic acid and removing by centrifugation;② stainless steel tubing with wider bore of 0.51 mm was used in the LC manifold system instead of the original in order to reduce the back pressure of the system to a lower value of 276 kPa to meet for the value of tolerable pressure of the immuno-affinity chromatographic column of 300 kPa.For the modified affinity LC method,linearity range was found between 200-2 000 mg·L-1 of IgG,and values of recovery of the method found by addition of standard IgG at concentration levels of 100 and 300 mg·L-1 were 112% and 97% with values of RSD′s (n=5) 4.2% and 3.9%,respectively.Analytical results of 13 health-care food samples found by the modified method were found to be in consistency with the CE method.