There are a number of factors that control the number of injections any modern HPLC column can withstand. Some of the factors are based upon the mode: reversed phase, ion exchange, size exclusion, normal phase, chiral, hydrophilic interation and so forth. Some of these factors are based upon the type of packing in the column — silica gel-, hybrid-, zirconia-, or polymeric-based packings or a soft gel or degree of crosslinking of resin. Some factors are based upon the phase itself: coverage, type of bond, polymeric, monolayer, or coated phase. Other factors are based upon the operating conditions: pH, temperature, mobile phase constituents, buffer composition, flow-rate, pressure and so on. Still other factors are based upon the sample that is injected: standards only, sample cleanliness, sample pH, sample volume, sample impurities present, solute molecules themselves and so on. Upon these factors, how many times we can inject sample in modern HPLC column.
according to my experience, it all depends, after treatment runs. on occasion have registered over 10,000 runs, however, there are researchers who have been fewer than 2000 runs, before appearing in the column damage.
To increase the lifetime of the column, it is advisable to use a single mobile phase.
Column life depends on the mobile phase, pH, Sample matrix, contamination and other factors. We can make approximately 1000-1500 injection onto a properly protected reversed phase column. Normal phase column have slightly shorter life spans, but should accept about 1000 injections. When subjected to extreme conditions, most columns will be stable for only a few hundred injections or less.
The general rule we use for all covalently bound silica based supports is ~ 2,000 injections. For some types of methods or samples this value could be much lower or higher. I recall a method where the column only lasted for about 300 injections. There is no way to estimate this, only generalize. In each case, it must be experimentally determined.
I think there is no general rule for this but it can be determined case by case according to the nature of your samples and mobile phase. Sometimes, I used a C18 column which tolerated > 5000 injections because I was mainly working on absolute standards without any biological samples. However, when I worked on biological samples, I hardly reached 3000 injections before the column spoiled despite washing and cleaning after each run.
What if the column in operated at high pressure sir? Does the life of silica decreases?
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