Use the temperature of the inlet to optimize the sample delivery for lower detectability of a wide range of analytes. Using the cool on-column mode of injection, even thermally labile compounds like N-nitrosodi-n-propylamine may be analyzed by GC. Cold split injections of C₉H₂₀-C₃₆H₇₄ alkanes yield uniform response eliminating the adverse effects of a hot needle injection. Large Volume Injections simplify extract concentration for sample enrichment.