Why HPLC Columns?
Columns contains stationary phase through which mobile phase passes and drug formulation comes in the contact with stationary phase helping in separation of API from formulation. The stationary phase is made up of silica. They are made of silica as they are one of the best absorbents present in the industry.
The image above is the inside structure of column containing structure of silica and the free hydroxyl group binds to the mobile phase which contains sample in it. There are various types of columns which are used in HPLC but they only differ in dimensions but all are made up of silica.
Why Reverse Phase Columns?
This column has polar mobile phase and non polar mobile phase. C-18 columns or octadecylsilane meaning silica attached to 18 membered long carbon chain. Due to this polar molecules elute out faster while non polar elute out slowly.
Advantages
- High resolution and sensitivity
- Wide Range of selectivity
- Compatible with range of detectors
- Detects non polar molecules like sterols, steroids etc.
Disadvantages
- Limited capacity for polar compounds.
- High backpressure due to small particle sizes.
Why Ion-Exchange HPLC Columns?
Ion-exchange columns separate analytes according to their charge. The stationary phase in these columns contains charged groups, which attract analytes with opposing charges. The mobile phase contains salt, which competes with the analytes for column binding. Ion-exchange columns separate charged compounds such as amino acids and proteins. Our ion-exchange HPLC columns are intended for high-resolution separation of complicated mixtures.
Advantages
- High Resolution for charged particles
- Good selectivity
- Protein Analysis
Disadvantages
- May lead to ion suppression
- Limited capacity for highly charged particles
Why Size-Exclusion HPLC Columns?
Size-exclusion columns use a porous stationary phase to separate analytes according to their size. Small molecules are confined inside the column's pores, but larger molecules flow through it more quickly. Size-exclusion columns are used to separate molecules according to their molecular weight. Our size-exclusion HPLC columns are intended for high-resolution separation of polymers and proteins.
Advantages
- Non destructive
- Simple preparation
- High resolution for large molecules
- Compatible with range of detectors
Disadvantages
- Limited Selectivity
- Long Run times
- Low efficiency
Why Normal Phase HPLC Columns?
Normal-phase HPLC columns contain a polar stationary phase and a non-polar mobile phase. They are effective for separating polar molecules like carbohydrates, amino acids, and peptides.
Advantages
- High capacity for polar compounds
- Separation of chiral compounds
- Gentle separation conditions
Disadvantages
- Can lead to lower sensitivity for non-polar compounds.
- Limited selectivity for some compounds.
Why Chiral HPLC Columns?
Chiral HPLC columns use a stationary phase containing chiral selectors to distinguish enantiomers. They work well with a variety of detectors and are both sensitive and accurate.
Advantages
- Good resolution for chiral compounds
- Compatible with range of samples
Disadvantages
- Expensive
- Lower Capacity
- Limited Selectivity
Types of Columns and their Dimensions
S.No | Column Name | Internal Diameter | Length | Particle Size |
1 | Standard Analytical Column | 1-1.46 mm | 10-30cm | 15-250 nm |
2 | Guard Column | 3.2 mm | 1-1.5 cm | 5-10 μm |
3 | Short Fast Column | 1-4.6 mm | 30-100 mm | 5-10 μm |
4 | Preparative Column | > 4.6 mm | 50-250 mm | 5-10 μm |
5 | Capillary Column | 0.1-1 mm | various | 5-10 μm |
6 | Nano Column | 0.1 mm | various | 5-10 μm |
7 | Narrow Bore Column | 4-5 mm | 150mm | 5-10 μm |
References
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