Advancements in Compound-specific Isotope Analysis (CSIA): Perspectives for Studying Reaction Mechanisms in Complex Systems
Investigating organic transformation mechanisms in complex environments (ground and surface water, living organisms, heterogeneous catalysis) is of fundamental importance in chemical sciences, yet challenged by the uncertainty whether lab-based studies adequately mirror real-world processes. Compound-specific stable isotope analysis (CSIA) of organic substances at natural isotopic abundance offers the potential to bridge this gap and to enable mechanistic reaction studies directly in complex systems. Through gas chromatography (GC) or liquid chromatography (LC) coupled to isotope ratio mass spectrometry (IRMS) the measurement of 13C-, 15N-, 2H- and 37Cl- isotope effects can be accomplished in pesticides, pharmaceuticals, chlorinated hydrocarbons and petroleum hydrocarbons at trace (microgram per liter) concentrations. This information does not only allow detecting degradation of chemicals in the environment in complex situations and over time scales otherwise not accessible (months to years). Isotope effect analysis of multiple elements also enables to elucidate transformation mechanisms (i.e. the manner and order of bond breaking) where conventional analysis provides complementary information about the identity of products (i.e. the net outcome of a reaction). My presentation summarizes analytical developments, presents latest results on the ability of CSIA to pinpoint micropollutant degradation in soil and groundwater and illustrates the capability of CSIA to elucidate underlying reaction mechanisms. This dual advantage of CSIA – the ability to tackle complex systems, yet to retrieve mechanistic information on the molecular level – offers prospects for studying degradation of chemicals in rivers, groundwater and engineered systems.
https://www.munich-geocenter.org/events/seminars/frontiers-in-earth-sciences-20/advancements-in-compound-specific-isotope-analysis-csia-perspectives-for-studying-reaction-mechanisms-in-complex-systems
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Advancements in Compound-specific Isotope Analysis (CSIA): Perspectives for Studying Reaction Mechanisms in Complex Systems
Abstract
Investigating organic transformation mechanisms in complex environments (ground and surface water, living organisms, heterogeneous catalysis) is of fundamental importance in chemical sciences, yet challenged by the uncertainty whether lab-based studies adequately mirror real-world processes. Compound-specific stable isotope analysis (CSIA) of organic substances at natural isotopic abundance offers the potential to bridge this gap and to enable mechanistic reaction studies directly in complex systems. Through gas chromatography (GC) or liquid chromatography (LC) coupled to isotope ratio mass spectrometry (IRMS) the measurement of 13C-, 15N-, 2H- and 37Cl- isotope effects can be accomplished in pesticides, pharmaceuticals, chlorinated hydrocarbons and petroleum hydrocarbons at trace (microgram per liter) concentrations. This information does not only allow detecting degradation of chemicals in the environment in complex situations and over time scales otherwise not accessible (months to years). Isotope effect analysis of multiple elements also enables to elucidate transformation mechanisms (i.e. the manner and order of bond breaking) where conventional analysis provides complementary information about the identity of products (i.e. the net outcome of a reaction). My presentation summarizes analytical developments, presents latest results on the ability of CSIA to pinpoint micropollutant degradation in soil and groundwater and illustrates the capability of CSIA to elucidate underlying reaction mechanisms. This dual advantage of CSIA – the ability to tackle complex systems, yet to retrieve mechanistic information on the molecular level – offers prospects for studying degradation of chemicals in rivers, groundwater and engineered systems.
