ABSTRACT
Photoionization and flame ionization are common detection techniques used for gas chromatographic (GC) systems in laboratory environments. Studies on using these two techniques for CWA detection have also been conducted. These techniques have very good sensitivity and large linear response dynamic range. They can sense a group of chemicals that can be ionized, and results are the sum of total detectable chemicals in the sample. Because of their nondiscriminative natures, these techniques are nonspecific for CWA and TIC detection. Although these methods can detect some organic CWAs and TICs with sufficient high volatility in the laboratory where the existence of the compounds is known, their nondiscriminative detection characteristics have prevented their usefulness in detecting highly toxic compounds under field conditions. Their main application as a field detector is for identifying volatile organic chemicals (VOCs). A separation method, such as the addition of a GC column ahead of the detection, is necessary to provide these technologies for potential identification of individual substance contained in a sample based on the elution times.
