Author Archive

Analysis of Nicotine and Related Compounds in Urine Using Raptor™ Biphenyl

As Applications Chemists in the LC lab, one of the most exciting parts of our jobs is the variety of analyses we are exposed to. One day you are developing a method for potency analysis in cannabis samples, the next you are looking at anti-epileptic drugs in urine.    We’re regularly challenged to think outside the […]

All of my peaks are tailing… What should I do?

I get quite a few customer questions concerning peak tailing during LC analysis, and how to best troubleshoot this issue.   Peak tailing may be attributed to a variety of different causes including secondary interactions, contamination, column loading, etc.   This list goes on and on.   I usually ask a few key questions, and generally can give […]

Shifting Analyte Retention Times or Matrix Interferences?

Occasionally, we will get a Technical Service call about peak retention times moving during a customer analysis.  Early eluting compounds are especially prone to this shifting, but the issue can often be attributed to matrix interferences that are also not well retained.    Pregabalin and Gabapentin are two antiepileptic drugs typically analyzed by LC-MS/MS.  Because of […]