Abstract: A chromatography analysis apparatus (30) comprises: a fractionation device (32) for receiving a sample, the fractionation device (32) defining a sample flow path that includes a guard column; and a fractionation output analyser (34), wherein a fractionation output of the guard column is provided to an input of the fractionation output analyser (34) for enabling subsequent analysis of the fractionation output by the fractionation output analyser (34).

Abstract: The present invention relates to a method for quantifying one or more analytes in a sample by an analysis system comprising a separation unit (LC column), a means of adding a solution post-column (Connector), and a detection unit comprising a mass spectrometer coupled through an ionization source, the method comprising: ? (i) inducing matrix effect on the analytes in the sample and on the post-column infused internal standards (PCI-ISs); ? (ii) matching one or more post-column infused internal standard (PCI-IS) to each analyte that best matches the analyte's response to the matrix effect, and ? (iii) storing the analyte-matched PCI-IS identification and, optionally, associated response data in a library; and ? (iv) applying the analyte-matched PCI-IS to the analyte in other samples to correct the analyte peak responses for the matrix effect during ionization and to obtain (absolute) quantitation of the analyte using the response data.