D- and L-amino acids in Antarctic lakes: assessment of a very sensitive HPLC-MS method

Anal Bioanal Chem. 2014 Sep;406(22):5259-70. doi: 10.1007/s00216-014-7961-y. Epub 2014 Jun 25.

Abstract

Amino acids represent a fraction of organic matter in marine and freshwater ecosystems, and a source of carbon, nitrogen and energy. L-Amino acids are the most common enantiomers in nature because these chiral forms are used during the biosynthesis of proteins and peptide. To the contrary, the occurrence of D-amino acids is usually linked to the presence of bacteria. We investigated the distribution of L- and D-amino acids in the lacustrine environment of Terra Nova Bay, Antarctica, in order to define their natural composition in this area and to individuate a possible relationship with primary production. A simultaneous chromatographic separation of 40 L- and D-amino acids was performed using a chiral stationary phase based on teicoplainin aglycone (CHIROBIOTIC TAG). The chromatographic separation was coupled to two different mass spectrometers--an LTQ-Orbitrap XL (Thermo Fisher Scientific) and an API 4000 (ABSciex)--in order to investigate their quantitative performance. High-performance liquid chromatography coupled with mass spectrometry methods were evaluated through the estimation of their linear ranges, repeatability, accuracy and detection and quantification limits. The high-resolution mass spectrometer LTQ-Orbitrap XL presented detection limits between 0.4 and 7 μg L (-1), while the triple quadrupole mass spectrometer API 4000 achieved the best detection limits reported in the literature for the quantification of amino acids (between 4 and 200 ng L (-1)). The most sensitive method, HPLC-API 4000, was applied to lake water samples.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acids / analysis*
  • Antarctic Regions
  • Chromatography, High Pressure Liquid / methods*
  • Ecosystem
  • Environmental Monitoring / methods*
  • Fresh Water
  • Lakes / chemistry
  • Mass Spectrometry / methods*
  • Peptides / chemistry
  • Quality Control
  • Stereoisomerism
  • Water Pollutants / chemistry
  • Water Pollutants, Chemical / analysis*
  • Water Purification

Substances

  • Amino Acids
  • Peptides
  • Water Pollutants
  • Water Pollutants, Chemical