Preparing Accurate Standard Gas Mixtures of Volatile Substances at Low Concentration Levels
- 39 Downloads
A simple approach for preparing standard gas mixtures of environmentally important volatile organic substances for gas chromatographic calibration is described. A liquid solution of the volatile substance of interest in a suitable solvent is prepared in a flask at known low concentration. Then, an easily measurable volume of this solution containing a very minute amount of the analyte is injected into a fixed-volume vessel (e.g., a glass sampling bulb) that has been flushed with a dilutent gas (e.g., air, N2, He). The generated gas-phase concentration of the substance after evaporation is easily calculated. This method allows students to prepare standard gas-phase mixtures at very low concentrations by direct injection of extremely small amounts into solution using a reasonable size microsyringe.
KeywordsConcentration Level Organic Substance Measurable Volume Simple Approach Direct Injection
Unable to display preview. Download preview PDF.