Solid phase extraction cleans up wines reproducibly and reliably, facilitating analysis of underivatized amino acids in wines. Mass detection enables the quantification of co-eluting amino acids, in comparison with method involving derivatization and UV or FL detection.
Implementation of a flow injection analysis-tandem mass spectrometry (FIA-MS/MS) method for simultaneous quantification of 13 amino acids and 13 acylcarnitines in dried blood spots. Newborn screening (NBS) is a public health program provided by most of the countries around the world aimed at screening newborns for a list of serious genetic and metabolic disorders.1-4 Determination of the amino acids and acylcarnitines profile is an integral part of the newborn screening programs.
Development of a sensitive and reproducible method for analysis of 22 underivatized amino acids and application of the method to quantify 17 amino acids in wine. Accurate quantification of proline, using an isotopically labeled internal standard.
In this Application Update, we combine into a single method individual improvements made to the standard AAA-Direct gradient program. These individual improvements are now in the AAA-Direct manual. This update shows that such combined changes to the AAA-Direct method improve the performance of our previously published method. This new method successfully determines amino acids in yeast extract-peptone-dextrose yeast culture medium (YPD Broth), and Dulbecco’s modified Eagle’s (with F-12), M199, L-15 (Leibovitz), and McCoy’s 5A media for mammalian cell culture.
In this technical note, we describe a procedure to screen sample matrices for their effect on peak area, peak height, and retention time. We demonstrate this procedure by testing ethanol for possible interferences in AAA-Direct. However, the method described here can also be used to evaluate any matrix component analyzed by chromatography with electrochemical detection. In this technical note, we use the term test sample (TS) to describe the specific test compound evaluated for possible interferences.
