Continuous stationary phase gradient preparation on planar chromatographic media using vapor phase deposition of silane.

A new, versatile, and straightforward vapor phase deposition (VPD) approach was used to prepare continuous stationary phase gradients (cSPGs) on silica thin-layer chromatography (TLC) plates using phenyldimethylchlorosilane (PDCS) as a precursor. A mixture of paraffin oil and PDCS was placed at the bottom of an open-ended rectangular chamber, allowing the reactive silanes to evaporate and freely diffuse under a controlled atmosphere. As the volatile silane diffused across the length of the TLC plate, it reacted with the surface silanol groups thus functionalizing the surface in a gradient fashion.

Preparation and characterization of stationary phase gradients on C8 liquid chromatography columns.

Continuous C8 stationary phase gradients are created on commercial Waters Symmetry Shield RP8 columns by strategically cleaving the C8 moieties in a time-dependent fashion. The method relies on the controlled infusion of a trifluoroacetic acid/water/acetonitrile solution through the column to cleave the organic functionality (e.g.

Use graphene coated silica core shell particles to provide rapid, precise, and equivalent chemical composition distribution analysis for polyolefin materials by high temperature thermal gradient interaction chromatography.

High temperature thermal gradient interaction chromatography (HT-TGIC) has been widely used to measure chemical composition distribution due to its applicability to separate crystalline and non-crystalline amorphous polyolefin materials. The compatibility of HT-TGIC with various detectors (infrared (IR), light scattering (LS), and viscometer) has also allowed a comprehensive analysis of molecular architecture of polyolefin and recycled plastics. The introduction of an easy-to-fabricate graphene coated onto non-porous silica particles as HT-TGIC column in 2020 showed a superior chromatographic performance over the traditional graphite column.