Chromatography Quiz #32

Chromatography Quiz #31: Glyphosate Doublet Peak – RESULTS

Pickering Labs would like to congratulate all of our winners for our previous newsletter’s Glyphosate Doublet Quiz: Jim Balk from Nebraska Public Health Environmental Laboratory, Tom Schneider from Suffolk County Water Authority, Narjes Ghafoori from LA County Public Health Laboratories, and Jiufeng Fan from Glaxo Smith Kline.

Winners will soon receive: An All-New Amazon Kindle Whitepaper!!!  The thinnest, lightest Kindle Whitepaper yet, this waterproof e-reader is sure to help our winners unwind with some beachside or poolside relaxation this summer!  Happy reading!

Congratulations to our quiz winners!

Thank you all for your submissions! 




The correct answers for the Glyphosate Doublet Peak quiz:

The Glyphosate ‘doublet’ is caused by injecting a sample at basic pH.  An improperly buffered sample extract at a large injection volume will not mix with the mobile phase sufficiently to create the acidic pH necessary for Glyphosate to be at the proper single charge state, impacting the interaction between Glyphosate and the active sites on the column resin.  Adding a couple drops of RestoreTM (pH 1.3) to the sample before injection will eliminate the ‘doublet’ and return proper peak shape. 

Chromatography Quiz #32 – I’m not seeing any peaks, Carbamates edition!

Identify the error made when running the Carbamates chromatogram below and win a prize! Simply email your answer and your full contact information to Rebecca at by August 30, 2019 in order to win.  You will receive email confirmation when your submission is received, and the troubleshooting answer and winner congratulations will be published in the next issue (to be anonymous, please notify Rebecca in submission). 

Good Chromatogram
HPLC Flow Rate: 1.0ml/min
Reagent Flow Rate: 0.3ml/min
Column Temp: 42C
Reactor Temp: 100C

Elution order:

Bad Chromatogram
HPLC Flow Rate: 1.0ml/min
Reagent Flow Rate: 0.3ml/min
Column Temp: 42C
Reactor Temp: 36C





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