8. Tailing peak (tailing peak): the trailing edge is the gentler asymmetric peak.
9. Leading peak: the leading edge is gentler than the trailing edge of the asymmetric peak. (Also known as tongue extension peak, forward extension peak).
10. Ghost peak: In addition to the chromatographic peaks normally generated by the components, the chromatographic peaks appearing on the spectrum due to changes in instrument conditions and other reasons, that is, peaks not generated by the sample. This chromatographic peak does not represent a specific component, and it is easy to give errors in qualitative and quantitative results. (Also known as Ghost Peak).
11. Distorted peak: Asymmetrically shaped chromatographic peaks. The peaks and trailing peaks belong to this category.
12. Negative peak: also known as inverted peak, negative peak, that is, the direction of the peak is opposite to the chromatographic peak in the usual direction.
Matters needing attention during the use of HPLC column
1. The HPLC column bed must always be kept dry, especially during the injection test and HPLC column flushing process, and the mobile phase should not be left empty for over 30 minutes. If not, the HPLC column will dry up and bring a large amount of non-ejectable bubbles, leading to partial collapse or central cracking.
2. It is strictly forbidden to use force to throw it and the accidental impact or falling at high places should be prohibited no matter in use or storage. Or, it will easily cause mechanical damage to the column bed, resulting from no regeneration ability.
3. The valve or pipe must be cleaned, when the HPLC column and the chromatograph are coupled.
4. Avoid using high viscosity solvents as the mobile phase.
5. The sample to be injected should be completely dissolved.
6. Most reversed-phase HPLC columns have a pH stability range of 2-7.5, which does not exceed the pH range of the column.
7. After the end of the analytical work, the sample remaining in the injection valve should be cleaned and the HPLC column should be cleaned with a suitable solvent.
8. If the analytical HPLC column is not used for a long time, it should be stored and sealed with a suitable organic solvent.