For GC analysis, the substance to be analyzed must be in the gaseous form. Because of this, the analysis of many organic compounds requires that injections, columns, and detectors are kept at relatively high temperatures. However, many organic compounds are thermally unstable. In such cases, it is necessary to convert the substance to be analyzed to a more volatile derivative appropriate for GC analysis. GC derivatizing reagents such as silylating, acylating, and alkylating reagents are used for this conversion.