Amino Acids, Peptides and Proteins - Dévényi T., Gergely J. 1976

Gas Chromatographic Analysis of Amino Acid Derivatives. State of the Art. Capabilities and Limitations of the Method
Special Instrumental Requirements and Experimental Conditions for GC Analysis of Amino Acid Derivatives and Peptides
Gas Chromatographs for Amino Acid Analysis and Their Requirements

Commercially available gas chromatographs must meet the following requirements:

1. The injector must feature a replaceable inlet liner to allow switching between Glass and quartz systems in different experiments. The liner should be easy to install, as it requires frequent cleaning. Temperature monitoring and control are essential during operation.

2. A uniform temperature must be maintained throughout the entire Column oven without gradients or fluctuations, both in isothermal and temperature-programmed Chromatography. The oven design should make column replacement a straightforward operation. The setup requires a set of glass and quartz columns with robust connections that maintain a tight seal over a long period, even with frequent column changes. Connecting tubing should be as short as possible to minimize dead volume between the injector and the column, as well as between the column and the detector. Ideally, the injector, column, and detector should be connected directly without any transfer lines.

3. Detection involves detectors with their own independent temperature control: a thermal detector, a gas density balance, a micro cross-section detector, and an electron capture detector. The detectors must be easily interfaceable with various instruments used for subsequent structural Analysis of the substance. They should be exceptionally stable, highly sensitive, and easy to clean. While the latter requirement is typically not mandatory in routine GC analysis, care must be taken to ensure it is met when analyzing Amino Acid Derivatives.

4. Electronic instruments, chart recorders, and measuring units must meet the criteria for quantitative GC analysis. In reality, however, even the latest models may exhibit non-linear characteristics. A specific feature of instruments equipped with electron capture detectors is that their response is inherently non-linear.

It is quite difficult to recommend any specific commercial instrument model as the most suitable for a particular application. Furthermore, custom-built instruments used in specialized Amino acid analysis research sometimes perform better than some commercially manufactured systems.