gel filtration chromatography (GFC) - size-exclusion chromatography carried out with aqueous mobile phases. Generally refers to separations carried out on soft gels such as polydextrans. Most gel filtration separations involve biopolymers.
gel permeation chromatography (GPC) - SEC carried out with organic mobile phases. Used for the separation and characterisation of polymers. SEC with aqueous mobile phases is referred to as a aqueous GPC, or GFC.
ghost-peak - spurious signal due to the different sources such as sample carry over in a syringe or injection valve, or accumulated contamination on the column eluted as ghost in gradient elution.
gradient elution - technique for decreasing separation time by changing mobile phase composition over time during the chromatographic separation. Also known as solvent programming. Gradients can be continuous or stepwise. Binary, ternary, and quaternary solvent gradients have been used routinely in HPLC.
See gradient elution in RP HPLC or gradient hardware..