LiChrospher®
Spherical silica sorbent for constant results on high level
LiChrospher® is a reliable and versatile traditionally produced spherical silica sorbent. LiChrospher® silica sorbents are available with different modifications. The polar modified phases LiChrospher® CN, LiChrospher® NH2 and LiChrospher® DIOL as well as LiChrospher® Si with no modification are best for normal phase HPLC.
Furthermore, LiChrospher® PAH is highly efficient and selective for the separation of PAH, as is LiChrospher® WP 300 RP-18 for the separation of peptides and low molecular weight proteins. LiChrospher® packing materials are available as Hibar® RT columns and as LiChroCART® cartridges in different lengths and different internal diameters (10 mm, 4 mm, 3 mm, and 2 mm).
LiChroCART® 3 mm i.d. and 2 mm i.d. narrow bore cartridges for HPLC save costs by reducing the solvent consumption; they enable the handling of very small quantities while achieving increased sensitivity as well as resolution. LiChroCART® cartridges 4 mm i.d., 3 mm i.d., and 2 mm i.d. are compatible with the manuCART® "4" NT. This facilitates faster and more flexible method adaptation to smaller bore columns. LiChroCART® cartridges 10 mm i.d. have to be used with manuCART "10"-II.
Specifications of LiChrospher® packing materials
| Packing material | Characteristics | Spec. surface area SBET (m2/g) | Pore volume VP (mL/g) | Particle size dP (µm) | % C | Surface coverage (μmol/m2) |
|---|---|---|---|---|---|---|
| LiChrospher® Si 60 |
Spherical particles of silica medium pore size: 6 nm (60Å) |
700 | 0.85 |
5,10 |
- |
- |
| LiChrospher® Si 100 |
Spherical particles of silica medium pore size: 10 nm (100Å) |
400 |
1.25 |
5,10 |
- |
- |
| LiChrospher® 100 CN |
Spherical particles of silica with cyanopropyl function |
350 |
1.25 |
5,10 |
6.6 |
3.52 |
| LiChrospher® 100 NH2 |
Spherical particles of silica with aminopropyl function |
350 |
1.25 | 5,10 |
4.6 |
4.10 |
| LiChrospher® 100 DIOL |
Spherical particles of silica with vicinal hydroxyl function on C-chains |
350 | 1.25 | 5,10 | 8.0 | 3.87 |
| LiChrospher® 100 RP-8 |
Spherical particles of silica with octyl derivative |
350 |
1..25 | 5,10 | 12.5 | 4.04 |
| LiChrospher® 100 RP-8 endcapped | Spherical particles of silica with octyl derivative endcapped |
350 |
1.25 | 5,10 | 13.0 | 4.44 |
| LiChrospher® 100 RP-18 |
Spherical particles of silica with octadecyl derivative |
350 |
1.25 | 5,10 |
21.0 | 3.61 |
| LiChrospher® 100 RP-18 endcapped |
Spherical particles of silica with octadecyl derivative endcapped |
350 |
1.25 |
5,10 | 21.6 | 4.09 |
| LiChrospher® 60 RP-select B |
Spherical particles of silica with octyl derivative, especially suitable for the RP separation of basic compounds |
350 |
0.9 |
5,10 | 11.5 | 3.55 |
| LiChrospher® WP 300 RP-18 |
Spherical particles of silica with octadecyl derivative |
80 |
1:0 | 5,12,15 |
Fraction range of LiChrospher® packing materials
| Packing material | Spec. surface area (m2/g) | Spec. pore volume (mL/g) | Fractionation range (Polystyrene/THF) (g/mol) |
|---|---|---|---|
| LiChrospher® Si 60 |
700 |
0.85 |
100 - 2•104 |
| LiChrospher® Si 100 | 400 | 1.25 |
200 - 7 •104 |
| LiChrospher® 100 DIOL | 350 |
1.25 | 200 - 4 •104 |
| LiChrospher® 100 RP-18 | 350 |
1.25 |
200 - 4 •104 |
| LiChrospher® WP 300 RP-18 | 80 |
1.0 |
4000 - 6 •105 |
Certified reproducibility of HPLC separations
The heart of each HPLC system is the column, where the separation of sample components takes place. Due to the chemical properties of silica, HPLC columns are subject to neutral wear, e.g. due to the irreversible adsorption of injected samples or sample matrix, or due to mechanical and chemical instabilities of the stationary phase. This will result in altered selectivities, "ghost peaks", diminished separation efficiency or excessively elevated column back pressures, preventing further column use. Hence, HPLC columns must be continuously changed out. This need not necessarily be problematic if the new column is one of the same type and has the same properties as the preceding one. The certified reproducibility of HPLC columns prevents extensive method revision as well as additional costs.
Separation performance, selectivity and capacity
Reproducibility of HPLC columns means that reproducibility is the most important property of an HPLC column, independent of the respective production batch. All columns of the same type should be reproducible and therefore comparable in terms of separation performance, selectivity and retention behavior. In its determination, a characteristic substance test mixture is subjected to chromatography under buffered elution conditions. The resulting chromatographic parameters, such as k-values, separation factors and the minimum number of theoretical plates, are fixed.
- Retention factor k (previously designated as ‘capacity factor k´) of a neutral compound means: the defined hydrophobic character of the stationary phase.
- Separation factors (i.e. relative retention times, previously designated as selectivity) bring about a defined order of elution and defined peak distance from batch to batch and cartridge to cartridge.
- Minimum number of theoretical plates (N) under buffered (not ideal) chromatographic conditions ensures separation performance.
Certified reproducibility of HPLC columns - No additional costs in method evaluation
The evaluation of quality control methods for certain products, e.g. in pharmaceutical applications, constitutes a considerable cost factor. The fact that an analytical method once established is used in expensive registration procedures for many years (up to 10 and more) requires thorough and careful elaboration. In this context, the selection of the HPLC column is an important decision criterion. The column certificate places the highest demands on process control during the batch-to-batch production of column materials. This ensures the customer constant HPLC column quality over many years.
