Analytical Tools in Indoor Chemistry

The chemical complexity of indoor surfaces and air creates challenges for quantitative analysis. The air includes inert trace gases, reactive trace gases, oxidants and radicals in the gas-phase, as well as particles across many orders of magnitude in size distribution. Measurements techniques must be able to capture the dynamic range and rapidly changing nature of indoor concentrations. Both passive and active sampling approaches are available, and chemical measurements may focus on speciated or bulk composition. The outdoor atmospheric chemistry community has established numerous on-line techniques for detecting trace gases and particles, and many of these techniques have been successfully applied to indoor environments. However, some of these techniques are subject to interferences in the indoor environment, requiring careful intercomparison. New frontiers in indoor analytical chemistry include development of new surface chemistry measurements, application of in situ chemical kinetics studies, development of low cost sensors, and closer linkage between health-relevant measurements and composition.