Isoprene measurements to assess plant hydrocarbon emissions and the methylerythritol pathway

Isoprene is the most abundant non-methane hydrocarbon emitted to the atmosphere and a target of biotechnology as a source of biofuels or chemical feedstock. Measurements of the amount of isoprene or the rate of production of isoprene are important for atmospheric chemistry, evaluating biotechnology processes, and can provide information on the capacity and regulation of the methyl erythritol 4-phosphate pathway found in plants and bacteria. In this chapter we discuss techniques, and their strengths and weaknesses, of methods in common use for measuring isoprene. There are many sources of isoprene for measurements including emissions from leaves and head space analysis of reactions involving recombinant enzymes or bacterial/fungal cultures. Similarly, there are a variety of detection methods including several mass spectrometer methods that are useful for examining rates of labeling of isoprene when carbon isotopes are used.