title: D- and L-amino acids in Antarctic lakes: assessment of a very sensitive HPLC-MS method.
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.
authors: Department of Environmental Sciences, Informatics and Statistics, University of Venice, Ca' Foscari, Calle Larga Santa Marta 2137, 30123, Venice, Italy, barbaro@unive.it.
authors: Elena
authors: E
authors: Barbaro
authors: Roberta
authors: R
authors: Zangrando
authors: Marco
authors: M
authors: Vecchiato
authors: Clara
authors: C
authors: Turetta
authors: Carlo
authors: C
authors: Barbante
authors: Andrea
authors: A
authors: Gambaro
mesh_terms: D000596:Amino Acids / Q000032:analysis*; D000864:Antarctic Regions; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D017753:Ecosystem; D004784:Environmental Monitoring / Q000379:methods*; D005618:Fresh Water; D060106:Lakes / Q000737:chemistry; D013058:Mass Spectrometry / Q000379:methods*; D010455:Peptides / Q000737:chemistry; D011786:Quality Control; D013237:Stereoisomerism; D014873:Water Pollutants / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis*; D018508:Water Purification
chemical_list: D000596:Amino Acids; D010455:Peptides; D014873:Water Pollutants; D014874:Water Pollutants, Chemical