Abstract
Currently available bonded phases
used in HPLC, UPLC and SPE employ silica particles as the base material. To
increase the phases applicability and adaptability, the surface of the
particles can further be modified by bonding a wide variety of functional groups
to the surface: non-polar (e.g. C18), polar (e.g. NH2), ionic (e.g.
propylsulphonic acid) or mixed-mode (e.g. C8/cation exchange). However, the state-of-the-art
approach to preparing bonded silica particles results in a number of inherent
shortcomings. For example, a thin coating of the bonded phase must provide all
of the required analyte/sorbent/stationary phase interactions, which imposes a
requirement of a high volume of stationary phase loaded into a long column size
to achieve a large sample breakthrough volume, which is the maximum sample
volume that can be passed through the column without saturating the bed with
the analytes. Often there is an insufficient organic group loading per unit
mass of the stationary phase/SPE sorbent to achieve adequate separation or
absorption. Finally, the state-of-the-art
phases display a very narrow range of pH stability, typically, at best, having
a robust stationary phase when maintained within a pH range of 2 to 8.FIU inventors have developed
sol-gel synthesis of alkyl functionalized (e.g., C4, C8, C12, C18) HPLC, UPLC and SPE sorbents. The synthetic method employs a tetrafunctional
silane and a trifunctional silane containing a sorbent functionality, for
example, tetraalkoxy silane and an alkyltrialkoxy silane or their equivalents
in presence of either an acid catalyst, an acid catalyst followed by a base
catalyst, or a base catalyst. This method yields a chemically and structurally
more stable highly porous hybrid inorganic-inorganic material. Due to the high
porosity and extremely high surface area, the HPLC stationary phase and SPE
sorbents offer more analyte-alkyl functional group interactions per unit mass
of the stationary phases/SPE sorbents, consequently minimizing the required
mass of the stationary phases/SPE sorbents to achieve target chromatographic
separation and extraction efficiency. Additionally, consumption of organic
solvents in chromatographic separation and sample preparation is significantly
reduced.
Benefit
Eliminates the use of preformed silica particles as the inert surface to graft different alkyl pendant groups via silane surface modificationDisplays high porosity and high surface areaOffers high chromatographic selectivity, separation power, and extraction efficiencyDisplays high thermal, chemical and solvent stability, as well as extended pH stability (pH 1-12)Requires less volume of solvent during chromatographic separation or SPE elutionEliminates solvent evaporation and sample reconstitution when used as SPE sorbents
Market Application
HPLC stationary phases in both convention columns (5 micrometer particle size)UHPLC columns (submicron particle size)SPE reverse phase sorbents
Brochure
