title: Ambient formaldehyde detection with a laser spectrometer based on difference-frequency generation in PPLN.
abstract: A laser spectrometer based on difference-frequency generation in periodically poled LiNbO3 (PPLN) has been used to quantify atmospheric formaldehyde with a detection limit of 0.32 parts per billion in a given volume (ppbV) using specifically developed data-processing techniques. With state-of-the-art fiber-coupled diode-laser pump sources at 1083 nm and 1561 nm, difference-frequency radiation has been generated in the 3.53-micrometers (2832-cm-1) spectral region. Formaldehyde in ambient air in the 1- to 10-ppb V range has been detected continuously for nine and five days at two separate field sites in the Greater Houston area operated by the Texas Natural Resource Conservation Commission (TNRCC) and the Houston Regional Monitoring Corporation (HRM). The acquired spectroscopic data are compared with results obtained by a well-established wet-chemical o-(2,3,4,5,6-pentafluorobenzyl) hydroxylamine (PFBHA) technique.
authors.affiliation: Rice University, Department of Electrical and Computer Engineering, Houston, TX 77251-1892, USA. Dirk.Rehle@gmx.net
authors.forename: D
authors.initials: D
authors.lastname: Rehle
authors.forename: D
authors.initials: D
authors.lastname: Leleux
authors.forename: M
authors.initials: M
authors.lastname: Erdelyi
authors.forename: F
authors.initials: F
authors.lastname: Tittel
authors.forename: M
authors.initials: M
authors.lastname: Fraser
authors.forename: S
authors.initials: S
authors.lastname: Friedfeld
mesh_terms: D001272:Atmosphere / Q000737:chemistry*; D004784:Environmental Monitoring / Q000295:instrumentation*; D004867:Equipment Design; D005069:Evaluation Studies as Topic; D005557:Formaldehyde / Q000032:analysis*; D007834:Lasers; D009556:Niobium; D010087:Oxides; D010126:Ozone / Q000032:analysis / Q000737:chemistry; D012815:Signal Processing, Computer-Assisted; D013055:Spectrophotometry, Infrared / Q000295:instrumentation*; D013781:Texas; D013997:Time Factors
chemical_list: D010087:Oxides; D009556:Niobium; C091692:lithium niobate; D005557:Formaldehyde; D010126:Ozone