METHOD AND APPARATUS FOR COLLECTING SAMPLES FOR ANALYSIS OF CHEMICAL COMPOSITION

摘要

An automated, on-line solvent elimination interface system is described for use in characterizing the Composition Distribution (CD) of unknown materials emerging from a fractionating unit or a process stream. Fractionated samples to be analyzed, such as a polymer, in highly diluted form in one or more solvents, are provided by a fractionation unit such as a gel permeation chromatograph (GPC), a high pressure liquid chromatograph (HPLC), or a field flow fractionator (FFF). A number of discharges of each particular fraction are supplied to individual collection units within the interface system under controlled conditions of flow rate, temperature and pressure (vacuum) such that the solvents are flash-evaporated at the collection unit. A sufficient solid residue is built up on the collection unit for analysis by, for example, a Fourier transform infrared (FTIR) analyzer.