Any type and amount of spherical or irregular silica gel can be delivered in bulk format, in different grades. Not only the often used flash silica 40-63um but also any type of silica-based solid phase extraction material as well as dedicated functionalized silica for synthesis or as scavenger is available in bulk.
Without bothering about packing yourself, ready to use pre-packed columns with any type of silica as described in de Silica Bulk section including solid phase extraction material are covered. Our Silica Specialties include several disks and depending on your needs, open or closed columns and of course TLC plates – both analytical and preparative. The columns can be coupled to loading adapters if needed.
The quality of a silica gel is extremely important when you are using it for chromatography purposes, particularly when dealing with difficult separations of valuable compounds. You need to be confident about your recoveries. In chromatography, there are at least three physical properties that will influence your separation and that you need to consider when choosing your silica gel:
- Particle shape (irregular or spherical )
- Particle size distribution (tight or large)
- Pore diameter (surface area)
These characteristics will directly influence crucial parameters involved in a successful chromatography:
- Resolution (efficiency of separation & final purity)
- Retention (which allows separation)
- Capacity (maximal sample quantity and final recovery/yield)
- Back-pressure (speed and pumps related issues)
For all the listed SiliaBond sorbents from SiliCycle, particle size is 40 – 63 μm and pore diameter is 60 Å. Please note that any irregular SiliaFlash or spherical SiliaSphere PC silica gel, with the function of your choice can be accommodated. Simply contact us for more information.
All functionalized SiliaBond sorbents are available in bulk but also pre-packed in SiliaPrep SPE cartridges and SiliaSep flash cartridges.
In geneal 3 type of phase are recognized in chromatography:
- In normal phase chromatography, the packing material is always polar while the mobile phase is non polar. The interactions between analytes and sorbent mainly take place on the highly polar silanols of the silica gel surface. Some hydrogen bonds can also happen on polar functionalized groups. Usual normal phases are ungrafted silica, polar functions (amino, cyano and diol) or alternative adsorbents (Alumina and Florisil for example).
- In reversed-phase chromatography, the packing material is always hydrophobic (non polar) while the mobile phase is polar. The more hydrophobic the packing material, the more retention of non polar analytes. Usual reversed-phases are standard alkyl chains grafted on silica (C18, C8, C4, C1) and cyclic or aromatic functions (Phenyl, Pentafluorophenyl, Cyclohexyl).
- Important parameters to keep in mind in reversed-phase chromatography:
- Carbon load (% C) will give the relative hydrophobicity of the packing media. Most of the time, it varies between 4% and 19%.
- Endcapping: it is impossible to react with all available silanol groups (free -OH groups on the silica surface) when functionalizing silica. But these free silanols are acidic and will react with basic compounds, so we endcap them with a capping agent to avoid non-specific bindings.
Ion Exchange Phases
- In ion exchange chromatography, both silica support and analytes must be ionized. If the stationary phase (packing material) is positively charged, anionic analytes only will retain (these phases are called WAX & SAX). And in the contrary if the stationary phase is negatively charged, cationic analytes only will retain (these phases are called WCX & SCX). Hence, pH of the mobile phase is of crucial importance and needs to be chosen carefully, so that both functions are charged.
SiliCycle is the leader in the development of functionalized silica gels, gathered under the name SiliaBond, for use in organic synthesis. The backbone of all SiliaBond products is SiliCycle SiliaFlash® F60 which provides superior performance for all types of applications due to the narrow particle size distribution and high purity. All the products in this section are made of standard flash silica gel, namely 40-63µm, 60A. SiliCycle is able to provide all functionalized products on any silica of this catalog (SiliaFlash, IMPAQ™, SiliaSphere™ and SiliaSphere™ PC) in any format (SiliaPrep™ SPE and SiliaSep™, SiliaSep, etc.) on a custom basis.
For over 18 years, SiliCycle has been offering a wide selection of TLC plates in various sizes (plate, thickness), backings (Glass, Aluminum, Plastic) and chemistries (CN, C18, NH2, 10% Silver Nitrate) to provide best separation experience for both qualitative and quantitative analysis. SiliaPlate represents an efficient and economical alternative to other TLC plate manufacturers while demonstrating high separation efficiency and low background noise, due to the narrow particle size distribution silica gel used for manufacturing.