Working Temperature, Protection, and Regeneration of HPLC Column
Temperature Control of HPLC Column
In the HPLC instrument, the HPLC column and some detectors are required to accurately control the temperature of the working environment, and the requirement for the constant temperature of the column is very high. The temperature has an effect on the solubility of the solvent, the performance of the HPLC column, and the viscosity of the mobile phase. Generally speaking, an increase in temperature can increase the solubility of the solute in the mobile phase, thereby reducing its partition coefficient, but it has little effect on the separation selectivity; it can also reduce the viscosity of the mobile phase, thereby improving the mass transfer process and reducing the column Pressure. However, if the temperature is too high, it is easy to cause bubbles in the mobile phase.
Temperature Change of HPLC Column
Different detectors have different sensitivity to temperature. The different working temperature of the HPLC column has an impact on the retention time and the relative retention time. When using soft fillers in gel chromatography, the temperature will cause changes in the structure of the fillers, which will affect the separation. However, if hard fillers are used, the effect is not significant.
Protection and Regeneration of HPLC Column
In the chromatographic analysis system, the HPLC column of high performance mainly plays the role of separating and detecting substances, such as the heart of the chromatographic system, and is also a vulnerable product. Some substances with smaller retention values, such as salts, are more likely to be washed into the column, while others with stronger retention, the mobile phase solution is not enough to elute these substances.
After multiple samples, these adsorbed on the surface of the column usually accumulate in the column header. When the adsorbed sample components accumulate to a certain extent, they can form a new stationary phase and change the separation mechanism, so that the sample retention time will fluctuate and the tail phenomenon will occur.
In order to prolong the service life of the chromatographic column, it has been pointed out that a small protective column should be connected in front of the analytical column. The function is to collect and block mechanical and chemical impurities from the sampler to protect and prolong the service life of the analysis column.
Therefore, the principle of selecting the protective column is to select the short protective column with low retention of the separation sample as far as possible on the premise of satisfying the separation requirements.
