Comparison of Fourier transform infrared spectrometry and 2,4-dinitrophenylhydrazine-impinger techniques for the measurement of formaldehyde in vehicle exhaust

• Published in: Analytical chemistry (Washington) Vol. 58; no. 1; pp. 68 - 72
• Main Authors: Haack, Larry P, LaCourse, Diane L, Korniski, Thomas J
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01.01.1986
• Subjects: Analytical chemistry; Chemistry; Exact sciences and technology; Spectrometric and optical methods; Emission measurement; Automobile; Fourier transformation; Chemical analysis; Analytical reagent; HPLC chromatography; Air pollution; Infrared absorption spectrometry; Exhaust gas; Comparative study; Formaldehyde
• ISSN: 0003-2700; 1520-6882
• DOI: 10.1021/ac00292a017

Experiments were conducted to validate a Fourier transform infrared (FT-IR) sampling and analysis system for measurement of trace gases in vehicle exhaust utilizing gasoline-gasohol-, diesel-, and methanol-fueled vehicles as the emission source and formaldehyde (HCHO) as the test molecule. The 2,4-dinitrophenylhydrazine impinger method was chosen as the reference method. Diluted exhaust was drawn continuously through the FT-IR cell and measured every 3 s. The FT-IR signals were averaged over a complete driving-test cycle and compared to the concentration determined from concurrent impinger sampling. By impinger measurements it was shown the HCHO losses between the tailpipe and the FT-IR cell were on the order of only 5%, independent of vehicle type or HCHO concentration (0.02-8.5 ppm). Comparisons between FT-IR and impinger measurements on 43 tests of methanol-fueled vehicles under transient conditions (diluted-exhaust HCHO 0.28-8.5 ppm) showed FT-IR/impinger = 1.055 plus or minus 0.095.