Our current research focus is centered on the real time atmospheric reactivity of hydroxyl radicals, emissions and chemistry of volatile organic compounds (VOCs)and the instantaneous ozone formation photochemistry, so as to develop a fundamental understanding of the processes that control the self cleansing (oxidizing) capacity of ambient air over the Indo Gangetic Plain. Towards this end, my group builds instruments (e.g. Kumar and Sinha, Int. J. Mass Spectrom, 2014 (see audioslides on Science Direct)) and deploys very sensitive online spectroscopic and mass spectrometric techniques for quantifying the ultra trace atmospheric chemical constituents (ppt-ppb). Kumar and Sinha, Int. J. Mass Spectrom, 2014, features among the most downloaded papers
We are the only laboratory in India to have developed an instrument (Kumar and Sinha, Int. J. Mass Spectrom, 2014 (see audioslides on Science Direct)) for quantifying atmospheric OH reactivity directly based on the innovative Comparative Reactivity Method (CRM) developed by Sinha et al.,Atmos. Chem. Phys., 2008, that has been emulated by leading research groups worldwide (e.g. USA, France and Germany). OH radicals are the "soap" of the atmosphere which prevent build up of toxic pollutant levels through fascinating chemistry. OH reactivity is a key chemical parameter that constrains the total reactive pollutant loading of air masses and enables instantaneous ozone production rates and regimes to be quantified (Sinha et al., Atmos. Chem. Phys., 2012).
Our laboratory is also the first group worldwide to deploy proton transfer reaction mass spectrometry (PTR-MS) technology within India and houses India’s first PTR-MS. This instrument quantifies highly reactive volatile organic compounds (VOC’s) in real-time at parts per trillion (ppt) level and has already been used to compile the first ambient dataset for reactive VOCs such as isoprene and acetaldehyde over the Indian region (see e.g. Sinha et al., Atmos. Chem. Phys., 2014).