Investigations of artifact peaks in sensitive high-performance liquid chromatography methods

Chromatograms of sensitive HPLC methods often show disturbing peaks, which mostly can be traced back easily. But sometimes such peaks are difficult to reproduce and therefore hard to trace. This paper describes two cases where artifact peaks arose due to contamination by the septum and by the sampling equipment, respectively, leading to misinterpretation of impurities and erroneous quantification. Furthermore, troubleshooting and ways to overcome these deficiencies are outlined.