Abstract: The present disclosure relates to the determination of analytes in a sample using chromatography. The present disclosure provides methods of separating an analyte from a sample. A mobile phase is flowed through a chromatography column. The mobile phase includes about 0.005% (v/v) to about 2.50% (v/v) difluoroacetic acid and less than about 100 ppb of any individual impurity, especially metal impurities. A sample including the analyte is injected into the mobile phase. The analyte is separated from the sample.

Abstract: The present disclosure relates to the determination of analytes in a sample using chromatography. The present disclosure provides methods of separating an analyte from a sample. A mobile phase is flowed through a chromatography column. The mobile phase includes about 0.005% (v/v) to about 0.20% (v/v) difluoroacetic acid and less than about 100 ppb of any individual metal impurity. A sample including the analyte is injected into the mobile phase. The analyte is separated from the sample.

Abstract: The present disclosure relates to a method of characterizing proteins in a sample. The method includes: removing non-ionic surfactant from the sample via denaturing size-exclusion chromatography to form a denatured sample; eluting the denatured sample via liquid chromatography to collect fractions of the sample, wherein the fractions of the sample include a protein fraction; lyophilizing the protein fraction to increase protein concentration; reconstituting the lyophilized protein fraction with a buffer comprising a surfactant to denature the protein; digesting the denatured protein fraction with an enzyme; and analyzing the digested protein fraction.

Abstract: The present disclosure pertains to methods for separating proteins from surfactants that comprise (a) adding an amount of denaturing buffer to a mixture comprising a protein and a surfactant thereby forming a denatured solution wherein the protein is denatured and (b) filtering the denatured solution with a molecular weight cutoff filter, thereby separating the protein from the surfactant and the denaturing buffer. The present disclosure also pertains to kits for forming such methods.

Abstract: The present disclosure relates to the determination of analytes in a sample using chromatography. The present disclosure provides methods of separating an analyte from a sample. A mobile phase is flowed through a chromatography column. The mobile phase includes about 0.005% (v/v) to about 2.50% (v/v) difluoroacetic acid and less than about 100 ppb of any individual impurity, especially metal impurities. A sample including the analyte is injected into the mobile phase. The analyte is separated from the sample.

Abstract: The present disclosure relates to the determination of analytes in a sample using chromatography. The present disclosure provides methods of separating an analyte from a sample. A mobile phase is flowed through a chromatography column. The mobile phase includes about 0.005% (v/v) to about 0.20% (v/v) difluoroacetic acid and less than about 100 ppb of any individual metal impurity. A sample including the analyte is injected into the mobile phase. The analyte is separated from the sample.