Determination of low-abundance proteins such as lactoferrin and β-lactoglobulin in dairy products is important due to their nutritional value.However,it imposes a difficult analytical task due to the presence of a very high level of abundance proteins such as caseins in dairy products.Various separation techniques such as gel electrophoresis and HPLC have been used in sequence to isolate the low abundance proteins from major proteins present in milk prior to their separation and determination1,2.The results are not satisfactory due to poor detection limits or co-migration of target proteins with other compounds.In order to solve such problems,a device coupling the poly (methyl methacrylate) (PMMA) microfluidic chip to capillary electrophoresis is developed using on-chip IEF to isolate major proteins from target proteins.Lactoferrin,β-lactoglobulin and other low abundance proteins are then transferred from a given length of the microfluidic channels with pls varying from 5.0 to 9.0 into an embedded capillary for transient ITP preconcentration prior to CZE separation for UV-Visible detection at 280 nm.Results on the applicability of the microfluidic-chip capillary electrophoresis device developed for the determination of Lactoferrin and β-lactoglobulin in infant formula will be presented and discussed at the meeting.