A laboratory intercomparison of real-time gaseous ammonia measurement methods

Schwab, JJ; Li, Y; Bae, MS; Demerjian, KL; Hou, J; Zhou, X; Jensen, B; Pryor, SC

HERO ID

2442502

Reference Type

Journal Article

Year

2007

Language

English

PMID

18200872

HERO ID 2442502
In Press No
Year 2007
Title A laboratory intercomparison of real-time gaseous ammonia measurement methods
Authors Schwab, JJ; Li, Y; Bae, MS; Demerjian, KL; Hou, J; Zhou, X; Jensen, B; Pryor, SC
Journal Environmental Science & Technology
Volume 41
Issue 24
Page Numbers 8412-8419
Abstract Six different measurement methods (and seven instruments) for the measurement of gaseous ammonia at low part-per-billion levels were compared simultaneously in a laboratory setting. The instruments were the tunable diode laser (TDL) absorption spectrometer, the wet scrubbing long-path absorption photometer (LOPAP), the wet effusive diffusion denuder (WEDD), the ion mobility spectrometer (IMS), the Nitrolux laser acousto-optical absorption analyzer, and a modified chemiluminescence analyzer. With the exception of the modified chemiluminescence analyzer, the instruments performed well and, under stable calibration conditions, generally agreed to within about 25% of the expected calibration value. Instrument time response is shown to be sensitive to measurement history as well as the sample handling materials and is shortest for the TDL. The IMS and Nitrolux are commercial instruments used without modification from the manufacturer. These two instruments have significantly slower time response than the TDL (especially in the case of the Nitrolux) and exhibited measurement biases of approximately +25% (IMS) and -25% (Nitrolux). The LOPAP and WEDD instruments, both research instruments using wet chemical methods, performed well in the calibration tests in terms of the absolute accuracy of measured concentrations, but the WEDD instrument suffered from significantly slower time response than the LOPAP.
Doi 10.1021/es070354r
Pmid 18200872
Wosid WOS:000251582800035
Is Certified Translation No
Dupe Override No
Is Public Yes
Language Text English
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