How to Reduce the Effect of Ionic Reagents on HPLC Columns?
Ion-pair reagents are an expression of the introduction of ion chromatography in high performance liquid chromatography. It is mainly a substance acting between the sample and the stationary phase, so when selecting the ion pair reagent, consider the acidity and alkalinity of the packing and sample of the HPLC column.
Effect of Ion Reagents on HPLC Columns
The ion-pairing reagent is adsorbed on the active site of the column packing, and it is difficult to be washed out, resulting in an increase in the dead volume of the column. Generally speaking, the column is shortened, and of course, the retention time is advanced, and the number of theoretical plates is decreased. The case where the degree of separation deteriorates. This adsorption process is irreversible, and even if the column is fully flushed, it will only partially restore the performance of the column and delay the time the column is scrapped.
This situation is somewhat similar to low molecular weight heparin. Ion chromatography detects free sulfate. Each time the sample is measured, the retention time is advanced. The more the number of samples, the more advanced the retention time is. However, this is a low molecular weight heparin sample adsorbed on the column.
How can I reduce the damage of the ionic reagent to the HPLC column?
For HPLC column storage, two things to avoid are: mildew caused by bacterial growth and dryness of the filler due to evaporation of the storage solvent. The organic phase component has a bactericidal effect and should not be too low in the preservation reagent; however, the 100% organic phase or close to the 100% organic phase is not good because it is too volatile. Therefore, 80% methanol water having a methanol content of up to and down is suitable as a storage solvent. Of course, no matter what you choose as a preservative, the Peek plug on both ends of the HPLC column must be plugged and plugged.