Quiz #45 – Amino Acids Rising Baseline
In this fast amino acids chromatogram (method abstract here), you will see a rising baseline at the time of injection. What is contributing to this baseline artifact? You will find an example of the rising baseline below along with Onyx PCX pump pressure trace.

Submit your answers to rsmith@pickeringlabs.com by November 15, 2024.
Announcing the winners of our previous quiz, Chromatography Quiz #44 – Amino Acids Noisy Baseline
Pickering Laboratories would like to congratulate the winners for our previous newsletter’s Chromatography Quiz: Jeff Fan from Thermo Fisher Scientific, Thomas Schneider from SCWA, Narjes Ghafoori from Los Angeles County Public Health Laboratory, and Josiah Hakala from Minnesota Department of Health.
They have won, and will shortly be receiving: Best Bloody Mary Mix Gift Box
Congratulations to our quiz winners! Thank you all for your submissions!
Chromatography Quiz #44 Solution:
In this amino acids chromatogram per European Pharmacopeia (method abstract here), you will see a noisy baseline with repetitive sinusoidal noise pattern (green and blue). What is contributing to this baseline noise?
Question: What is causing the baseline noise?
Correct answer:
In this case, the noise in the baseline was caused by the HPLC pump. The seal/needle wash bottle had dried up, causing abnormal pressure fluctuations and leading to sinusoidal spikes in the baseline.