Capillary gas chromatographic analysis of amino acids in geological environments with electron capture detection

Studies have been performed on the analysis of 21 amino acids using a fused‐silica open tubular (FSOT) capillary column, and electron‐capture detection (ECD) or flame‐ionization detection (FID). It was shown with the N(O) ‐heptafluorobutyryl (HFB) amino acid isobutyl esters that the ECD response was several hundred times more sensitive than the FID response. The relative standard deviation (RSD) of retention relative to norleucine is determined with the ECD. RSD values for all N(O) ‐HFB amino acid isobutyl esters are relatively small (≦ 0.5%). This method has been successfully applied to trace analysis of most of the amino acids from fossil brachiopods and black shales.