The Application Notebook
Amino acids have significant biological importance, as they are the building blocks of life, and they are also used in nutritional supplements, fertilizers, and food technology. Industrial amino acid use includes the production of drugs, biodegradable plastics, and even chiral catalysts. With the wide variety of uses, there are many ways to classify amino acids, including polarity, pH, size, hydrophobicity, side chain group type, and so on. However, the ideal quantitative analysis of amino acids combines speed and sensitivity with reliability of the analytical technique.
Many columns cannot offer a single method to analyze the 20 building block amino acids. Shodex introduces the new HILICpak VC-50 2D column, which can offer speed, sensitivity, and reproducibility. This column is packed with polyvinyl alcohol material with carboxyl functional groups. When used according to the protocol described below, the column enables the user to analyze all 20 amino acids using a single method. A single run can be completed in 25 min with good resolution. In addition to analyzing the essential amino acids, the VC-50 2D has been shown to separate amino sugars.
Experimental Conditions
Each amino acid was dissolved in water and diluted to 0.1 μg/mL. The analysis of all 20 amino acids was successfully accomplished with the Shodex HILICpak VC-50 2D (2.0 mm ID x 150 mm), a polymer-based column for HILIC analysis. A 5 μL measure of each sample was injected into the system. The column temperature was kept at 30 oC and a flow rate of 0.2 mL/min. Eluent conditions were H2O/100 mM HCOOH aq./CH3CN = 30/20/50 to 0/90/10 (0 to 5 min), 0/90/10 (5 to 30 min) in a lower pressure linear gradient. The HPLC system was coupled with an ESI-MS SIM detector.
Results
The Shodex team has successfully developed a method for detecting 20 amino acids using a single method on the HILICpak VC-50 2D under positive MS mode. From the data shown above, isoleucine and leucine have some overlap. Through some modifications to the method, this analysis can result in a better separation. The Shodex HILICpak VC-50 2D is an ideal column for amino acid analysis.
ShodexTM/Showa Denko America, Inc.
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SEC-MALS of Antibody Therapeutics—A Robust Method for In-Depth Sample Characterization
June 1st 2022Monoclonal antibodies (mAbs) are effective therapeutics for cancers, auto-immune diseases, viral infections, and other diseases. Recent developments in antibody therapeutics aim to add more specific binding regions (bi- and multi-specificity) to increase their effectiveness and/or to downsize the molecule to the specific binding regions (for example, scFv or Fab fragment) to achieve better penetration of the tissue. As the molecule gets more complex, the possible high and low molecular weight (H/LMW) impurities become more complex, too. In order to accurately analyze the various species, more advanced detection than ultraviolet (UV) is required to characterize a mAb sample.