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

• Published in: Analytical and Bioanalytical Chemistry
• Main Authors: BARBARO, ELENA, Zangrando, Roberta, VECCHIATO, MARCO, Turetta, Clara, BARBANTE, Carlo, GAMBARO, Andrea
• Other Authors: Barbaro, Elena, Vecchiato, Marco, Barbante, Carlo, Gambaro, Andrea
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2014
• Subjects: Amino acids; Chiral separation; Antarctica; HPLC-MS/MS; HPLC-orbitrap; Lakes NORTHERN VICTORIA-LAND; CHIRAL STATIONARY-PHASE; PERFORMANCE LIQUID-CHROMATOGRAPHY; ELECTROSPRAY MASS-SPECTROMETRY; DISSOLVED ORGANIC NITROGEN; MCMURDO DRY VALLEYS; TERRA-NOVA BAY; WATER; SEPARATION; ECOSYSTEMS; Settore CHIM/01 - Chimica Analitica; Antarctic; Victoria Land; McMurdo Dry Valleys; Terra Nova Bay; Antarc*
• Online Access: http://hdl.handle.net/10278/43249; https://doi.org/10.1007/s00216-014-7961-y

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 mu g 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.