The C18 column is an octadecylsilane bonded silica packing (Octadecylsilyl, ODS for short). This kind of packing plays an extremely important role in reversed-phase chromatography, which can complete 70-80% of the analytical tasks of high-performance liquid chromatography. Because C18 (ODS) is a long-chain alkyl bonded phase, with higher carbon content and better hydrophobicity, it is the most widely used type of bonded phase in chromatographic analysis.
C18 column is our core product. There are variety of models are available, mainly including conventional reversed-phase columns, 1.8μm ultra-high pressure analytical columns, and core-shell analytical columns. This article will mainly introduces a variety of models of our HPLC column, tolerance pH range, various chromatographic column has its own characteristics comparison.
Ultisil®XB – C18
pH tolerance range: 1.5-10.0
Characteristics
- One of the best chromatographic columns with comprehensive separation performance and universality;
- Classic “star” products, excellent performance, extremely stable stationary phase, with complete batch tracking and reproducibility;
- Pharmacopoeia uses mainstream chromatographic column to detect acidic and alkaline polar substances with good peak shape, which is your preferred conventional method.
The Ultisil®LP – C18
Tolerance pH range: 0.5-8.0
Characteristics
- Resistant to 100% water and 100% organic solvents;
- Side chain steric protection shielding hydroxyl;
- No tail sealing process;
- Strong spatial location selectivity;
- It has strong orthogonality with conventional C18 and can not be separated on conventional C18.
- The ideal baseline noise can be obtained by using ELSD detector under strong acid condition, indicating that the loss of bonding phase is small under strong acid condition.
- Good column life can be guaranteed at high temperatures up to 80°.
Ultisil®AQ – C18
pH tolerance range: 1.5-10.0
Characteristics
- Resistance to 100%-0% water phase;
- Double tail sealing process;
- Moderate carbon load; Alkyl chain bonding density is low;
- Moderate retention capacity;
- The adsorption capacity for impurities is weaker than xB-C18.
- In chemical drug content measurement, the first pillar of the food industry.
Ultisil®PLUS C18
pH tolerance range: 2.0-8.0
The characteristics of
- Lower specific surface area, slightly larger aperture;
- The retention capacity of XB-C18 is weaker than that of XB-C18 due to its lower carbon load.
- Double tail sealing process;
- It has good peak shape when detecting acidic and alkaline polar substances.
- Best choice for retaining too strong material on XB-C18.
Ultisil®ALK-C18
pH tolerance range: 1.5-10.0
Characteristics
- Lower specific surface area, slightly larger aperture;
- The retention capacity of XB-C18 is weaker than that of XB-C18 due to its lower carbon load.
- Double tail sealing process;
- It has good peak shape when detecting acidic and alkaline polar substances.
- Best choice for retaining too strong material on XB-C18.
Ultisil®ODS-3
pH tolerance range: 2.0-8.0
Characteristics
- General purpose, compatible with 100% water;
- The adsorption of alkaline and acidic compounds is small, which makes the compounds have perfect peak shape on the chromatographic column.
Ultisil®XS – C18
pH tolerance range: 1.5-10.0
Characteristics
- The unique multi-layer bonding process has high bonding density, close space distance between ligands and good shape selectivity.
- High column efficiency, high column capacity, high carbon load, strong retention ability of compounds, and excellent steric hindrance selectivity;
- For small molecular objects, the selectivity is prominent, like foreign bodies, isomerism position.
Ultisil®Polar RP
pH tolerance range: 1.5-10.0
Characteristics
- Reversed phase column with different selectivity from ordinary C18;
- When the ratio of organic phase in mobile phase is very low (even 100% water mobile phase), the alkyl phase can be wetted by water solvation without phase collapse.
- The retention and selectivity of polar substances are better;
- C18 is the preferred column for detecting organic acids.
Xtimate®C18
pH tolerance range: 1.0-12.5
Characteristics
- The organic and inorganic hybrid surface technology patented by Welch is used to modify the silica gel matrix, which is specially designed for the development of liquid chromatography methods. It can be developed in a wide PH range using a variety of mobile phase systems and a wide temperature range.
- Under the most demanding conditions, also has very stable performance and longer life, conventional conditions than ordinary C18 longer life, the use of advanced innovative technology production, and according to strict quality standards for quality control, is the user for difficult chromatographic separation of the trustworthy solution;
- The alkaline substances with easy trailing have excellent peak shape in neutral condition.
Topsil®C18
pH tolerance range: 2.0-9.5
Characteristics
- A relatively economical column;
- The selectivity is slightly different from Ultisil XB-C18, the column effect is 80,000/m, the column pressure is relatively low, the separation of complex substances is worse than that of XB-C18, do some simple substances, and need the first choice of economic chromatographic column.
Welchrom®C18
pH tolerance range: 1.5-10.0
Characteristics
- Economical column, low column pressure, low price, high cost performance, the same price of products in the leading performance.
Blossmate®C18
pH tolerance range: 2.0-8.0
characteristics
- High-end column series;
- Compared with other product series, Blossmate C18 series has achieved all-round improvement in column performance and reproducibility, making it especially suitable for multi-component impurity detection and application.
Blossmate ® PSV C18 Plus
pH tolerance range: 2.0-8.0
Characteristics
- Special column for food preservative detection;
- High-end new high column efficiency, high proportion of water phase tolerance;
- It has high selectivity and strong retention ability for hydrophilic and polar compounds, which are difficult to be retained and separated on ordinary C18 columns.
- The complete sealing technology greatly enhances the stability of the packing, showing stable baseline and high sensitivity even at neutral pH, so it is especially suitable for the efficient separation of LC MS and other combined technologies.
- The integrated design of protection column and analysis column is used to add protection column at the front of the analysis column to protect the analysis column in all directions. At the same time, the dead volume is small, easy to replace the core;
- It has better separation and retention ability, better peak shape and higher column efficiency.
Blossmate®ST C18
pH tolerance range: 1.0-11.0
Characteristics
- Using special silica gel substrate surface treatment technology, in order to ensure high mechanical strength and high column efficiency of silica gel substrate, but also broaden the pH tolerance range to 1.0-11.0;
- Suitable for alkaline sample analysis and method development under higher pH conditions.
Blossmate®Aqs C18
pH tolerance range: 2.0-8.0
Characteristics
- It can be compatible with pure water phase and pure salt phase. Under the condition of high proportion of water phase, the column still has excellent stability and high column efficiency.
- It is suitable for the analysis of high hydrophilic samples and large polar samples.
If you have any problem or require further information, please contact info@welchmat
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