Chromatograpy Quiz No. 12

Chromatography Quiz #11 Results

We would like to congratulate all six grand prize winners of our last newsletter’s Glyphosate Analysis Chromatography Quiz: Thomas Schneider from Suffolk County Water Authority, Hélène Lachance from Shur-Gain Nutreco in Canada, Jim Balk from DHHS Public Health Environmental Laboratory, Tom Phillips from Maryland Department of Agriculture, Matthew Hartz from Underwriters Laboratories, and Narjes Ghafoori from the LA County Environmental Toxicology Laboratory!!!

tea They have each won and will be receiving: a wooden chest of premium and specialty teas by Silkenty Tea (purchased from!  We would like to thank all of you for your submissions.



The correct answer for the modified Glyphosate chromatogram: Iron contamination has been introduced into the system and has fouled the column, resulting in poor peak shape and a retention time shift in AMPA.  If the problem worsened, the peak shapes would continue to deteriorate and eventually the Glyphosate peak could vanish completely.

The recommended action would be to reverse-flush the column with RESTORE™. The presence of polyvalent metal ions (especially iron) can rapidly lead to serious degradation of column performance.

Thank you!

Pickering Labs

Chromatography Quiz #12:

Identify the error made when running the Amino Acids chromatogram below and win a prize!  Simply email your answer as well as your full contact information to Rebecca at by April 30, 2013 in order to win.  You will receive email confirmation that your submission has been received.  The troubleshooting answer and winner congratulations will be published in the next issue (to remain anonymous, please notify Rebecca in submission).

Amino Acid Analysis – Baseline Noise

Pinnacle PCX post-column instrument is being used, in a traditional HPLC setup as recommended by Pickering Labs.  The chromatogram is a close-up of a customer’s reoccurring baseline noise, and the quiz question is: what is causing the noise?

Post-column conditions for amino acid analysis:

Reagent 1: Trione

Reactor 1: 130 °C, 0.5 mL

Reagent flow rate: 0.3 mL/min


UV-Vis Detector:  570 nm for primary amino acids,  440 nm for secondary amino acids

Please use our website to view any reference Amino Acid chromatogram – this quiz is not application-specific per say, and as such any of our AAA methods could be applicable.  If you have any questions, please don’t hesitate to email Rebecca at

bad baseline chromatogram quiz 12