Size exclusion chromatography, HPLC selectivity

The only predictable selectivity in HPLC is that that provided by the non-interactive conditions that may be achieved with the porous adsorbents used in nonaqueous size exclusion chromatography. Predictability is based on a knowledge of the relative pore and solute sizes. The optimal size ratio for solute separation is four to one (13). 

HPLC, with all its different modes of separation [normal phase, reversed phase, ion exchange, size exclusion chromatography (SEQ, and FIILIC], is well suited for 2-D, or even 3-D. The separation can be carried out online by connecting two different selectivity columns in series or by packing a single column with two different selectivity materials. 

Modern high-performance liquid chromatography (HPLC) is a versatile analytical technology that can provide a range of essential information about the soluble components of plastics, including the base polymer, the formulated resin, and the additives. All modes of HPLC use a column packed with materials to separate species in a complex mixture. In some modes of HPLC the separation is based on differences in chemical composition or selectivity. The mode of HPLC that is most familiar to polymer analysts is gel permeation chromatography (GPC). It is also termed size-exclusion chromatography (SEC). 

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