Incoherent broad-band cavity-enhanced absorption spectroscopy of the marine boundary layer species I2, IO and OIO.
The novel combination of incoherent broad-band cavity-enhanced absorption spectroscopy (IBBCEAS) and a discharge-flow tube for the study of three key atmospheric trace species, I(2), IO and OIO, is reported. Absorption measurements of I(2) and OIO at lambda=525-555 nm and IO at lambda=420-460 nm were made using a compact cavity-enhanced spectrometer employing a 150 W short-arc Xenon lamp. The use of a flow system allowed the monitoring of the chemically short-lived radical species IO and OIO to be conducted over timescales of several seconds. We report detection limits of approximately 26 pmol mol(-1) for I(2) (L=81 cm, acquisition time 60 s), approximately 45 pmol mol(-1) for OIO (L=42.5 cm, acquisition time 5 s) and approximately 210 pmol mol(-1) for IO (L=70 cm, acquisition time 60 s), demonstrating the usefulness of this approach for monitoring these important species in both laboratory studies and field campaigns.
Vaughan
Stewart
S
Department of Physics, University College Cork, Cork, Ireland.
Gherman
Titus
T
Ruth
Albert A
AA
Orphal
Johannes
J
D000393:Air Pollutants / Q000737:chemistry; D005740:Gases; D007455:Iodine / Q000737:chemistry*; D017613:Iodine Compounds / Q000737:chemistry*; D009792:Oceans and Seas; D010100:Oxygen / Q000737:chemistry*; D013057:Spectrum Analysis / Q000295:instrumentation* / Q000379:methods*
D000393:Air Pollutants; D005740:Gases; D017613:Iodine Compounds; D007455:Iodine; D010100:Oxygen