Chromatography Forum

hi there is an observation was made by me during my analysis i.e my standard peak height is 500AU and sample peak height is 800AU but both have same area it is in Assay By HPLC Usp method
1.both preparations are made at same concentrations i.e 0.5mg/ml
2.HPLC system is Shimadzu Prominence UFLC with LC-Solutions database software
3.it was observed only two times but i am analysing daily the samples with same standard and same analyticalcolumn (RP18e,250x4.5mm,3µm) and also more times in same instrument

Let the speculation begin !

Two possibilities: the lower peak is wider than the higher one (for whatever reason), or 300 MAU of inconsistent baseline drift.

Peter

What are the respective retention times?
What will happen if you repeat the injections?

Best Regards

That´s it: The peaks are not at the same retention time.