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.
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.
Therapeutic proteins (antibodies and vaccines) vary considerably and unwanted aggregation is a major path to degradation. Stabilization of protein formulations can be enhanced through the addition of specific excipients such as amino acids, ions, surfactants and sugars. A 2D “heart cut” technique allows the separation of the protein component of a commercial therapeutic formulation and analyzed using a DAD detector and polar sugar and amino acid excipients to be separated on the second dimension using ion-pairing RP conditions and detected via the charged aerosol detector.
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.
This Technical Note describes the peptide hydrolysis procedures that lead to successful determinations of amino acid composition using AAA-Direct. Results for the amino analysis of two peptides, Melanocyte Stimulating Hormone (MSH) and Luteinizing Hormone-Releasing Hormone (LH-RH), using both hydrochloric acid and methanesulfonic acid (MSA) as hydrolyzing reagents are presented to demonstrate the performance of this method.
