One of the challenges facing both regulators and the regulated community in dealing with air toxic emissions and their control, is the need to accurately measure and characterize these emissions. The current technology for measuring metallic components in emission streams requires manual sample extraction, recovery and preservation of the sample, and finally analysis of the sample using laboratory instrumentation. While these techniques are capable of analyzing trace concentrations of metals with adequate accuracy and precision, they all have numerous drawbacks due to their complexity and the fact that they do not provide real-time data. This paper describes two programs that ADA Technologies has undertaken to develop measurement technology for toxic metals in combustion flue gas. These research programs are directed at overcoming limitations of the current state-of-the-art measurement systems in order to meet the needs for accurate and reliable monitoring of toxic metal emissions from stationary sources. Both programs focus on the development of instrumentation for the detection and quantization of trace levels of air toxic metals in combustion gas environments. The instruments are being designed to function as continuous, real-time, on-line analyzers that can serve as parts of a feedback process to control air toxic metals emissions.