Quantification of Guanidine in Environmental Samples using Benzoin Derivatization and LC-MS Analysis

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Abstract

The recent discovery of guanidine-dependent riboswitches in many microbes raised interest in the biological function and metabolism of this nitrogen-rich compound. However, very little is known about the concentrations of guanidine in the environment. Several methods have been published for quantifying guanidine and guanidino compounds in human urine and blood, often relying on derivatization followed by fluorescence detection. We adapted this analytical approach using benzoin as the derivatization agent to sensitively and selectively quantify guanidine in environmental samples, thereby facilitating future research on the biological and environmental roles of guanidine. This adapted method was applied to human urine, raw wastewater, and biological growth media as relevant matrices. Our liquid chromatography-tandem mass spectrometry analyses of the derivatized solutions identified a different major derivatization product than previously reported. This product was consistently observed across various substrates (guanidine, methylguanidine, and arginine) and derivatization agents (benzoin and anisoin). We observed a constant background signal, restricting our analyses to a lower limit of quantification of 50 nM. Despite this limitation, our method allowed for the quantification of guanidine concentrations significantly lower than those reported in previous derivatization-based studies.
• Selective and sensitive detection of guanidine by LC-MS.
• Method development and validation for robust detection of guanidine in environmental samples.
• Reduction of sample preparation steps and reduced usage of toxic chemicals compared to previous methods.
Original languageEnglish
Article number102972
Number of pages15
JournalMethodsX
DOIs
Publication statusAccepted/In press - 24 Sep 2024

Austrian Fields of Science 2012

  • 104023 Environmental chemistry
  • 106022 Microbiology
  • 106026 Ecosystem research

Keywords

  • Guanidino Compounds
  • Environmental and Biological Matrices
  • Urine
  • Liquid Chromatography Coupled to Mass Spectrometry

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