Not completely replaceable in all cases
In high-performance chromatographic analysis, the choice of chromatographic column directly affects the effect of separation and the sequence of peaks. Choosing a suitable chromatographic column can shorten the time required for method development and make the detection results more stable; even if they are all C18 columns, Different series of the same brand will produce different detection effects in the detection of the same item due to the difference in selectivity, and even the composition of peaks and the order of peaks will be different.
Separation of related substances in a sample:
Substance 1, Substance 2, Substance 3，
It can be found from the spectrum that the three substances have different separation effects on C18 chromatographic columns with different selectivities. The three components of chromatographic column 1 can achieve relatively perfect separation before, while in other C18 The composition of the peaks on the chromatographic column is not the same. If the single standard is not used for positioning, the exact position cannot be determined.
Therefore: the selectivity difference of the same test item on different C18 chromatographic columns may be quite different. During the test, if a different type of chromatographic column is replaced, even if they are all the same bonded phase, they need to be positioned with a single standard and re-installed. Qualitative, so as to avoid misjudgment due to the ectopic peak after replacing the chromatographic column.