Chemical Processes & Instrument Development: Instruments

Instruments in our laboratory are primarily used to study fundamental processes that occur in the atmosphere via the characterization of the chemical and physical properties of atmospheric trace species. Laboratory instruments are used in the development of experimental methods to measure the reactivity and photochemistry, as well as, the optical and physical properties of stable, transient, and radical species. The experimental apparatus and methods used in our laboratory are designed to selectively detect species with high sensitivity under various temperature and pressure conditions on time scales ranging from nanoseconds to hours. No individual instrument is, however, capable of meeting all the requirements necessary to study all processes. Therefore, the instruments described below are commonly used in combination to develop a more comprehensive picture for a specific species or process.

InstrumentApplications
RF Atomic Resonance Fluorescence Reaction rate coefficient measurements, photolysis quantum yields (H, O, Cl, Br) RF
CRDS Cavity Ring-down Spectroscopy (co-linear photolysis) Temperature and pressure dependent reaction rate coefficient measurements, product yields, absorption spectra, photolysis quantum yields CRDS
CIMS Chemical Ionization Mass Spectrometer Temperature dependent reaction rate coefficients, reaction product yields, heterogeneous chemistry/uptake measurements CIMS
DA Diode Array Spectrometer UV absorption spectra, photolysis quantum yields DA DA
DW-CRDS Dual Wavelength Cavity Ring-down Spectroscopy Reaction rate coefficients, product yields, spectrum measurements, photolysis quantum yields DW-CRDS DW-CRDS
ESI-MS ElectroSpray Ionization Mass Spectrometer Aqueous-phase chemistry, reaction mechanisms and product yields ESI-MS schematic
FTIR Fourier Transform Spectrometer High-resolution infrared absorption/emission spectra, absorption cross sections, reaction rate coefficients (RR), reaction product yields, reaction mechanisms FTIR FTIR
LIF Laser Induced Fluorescence Temperature and pressure dependent reaction rate coefficient measurements, product yields, OH photolysis quantum yields LIF
NPF New Particle Formation New particle formation mechanisms, nucleation and condensation yields NPF
RR Relative Rate Reactor Temperature and pressure dependent reaction rate coefficients (OH, Cl, O3, and NO3), reaction mechanisms, reaction product yields RR
S&H Solubility and Hydrolysis Henry's law coefficient measurements, hydrolysis rate coefficients and product yields S&H