Demand for hazardous material monitoring is ever increasing, as we become more aware of the dangers of chemicals used in industrial processes and the need for personnel and environmental protection. One set of materials – Volatile Organic Compounds (VOCs) – can be detected with Photoionization. This is the term for the absorption of high energy photons by a molecule which results in ionization of that molecule. The ionization current is proportional to the concentration of the molecule. This provides a simple method for quantitative analysis of a variety of compounds. The technique is nondestructive so can be used in conjunction with other detectors for extending the analysis.