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Shengsi Liu_Analytical Problem_CO detection in post combustion fuel

Most of the energy we use today comes from the combustion of oil, coal and natural gas. These fuel, when undergoing the combustion process emits a some amount of carbon monoxide (CO) due to partial oxidation of carbon-containing fuel compounds. CO is colorless and tasteless, but highly toxic. CO concentration as low as 667 ppm may cause up to 50% of the body's hemoglobin, an important complex to delivering oxygen inside the human body, to convert to carboxyhemoglobin that are unable to function as oxygen deliverer. Besides from human poisoning, CO is also one of the major urban pollutants coming from the exhaust of internal combustion engines.Thus it is important to keep track of the levels of CO in the atmosphere.

The central hypothesis is that the exhaust of internal combustion engines contains a slight amount of CO which can be collected and be analyzed in order to find the concentration of CO per volume. This value can further be used to estimate if the toxicity of the exhaust of the fuel. Thus the analyte is CO and the matrix it is found is a mixture of sulphur dioxide (SO2), nitrogen oxides (NOx), carbon monoxide (CO) and carbon dioxide (CO2).

1. Omaye ST. Toxicology, 2002,180 (2), 139-150.
2. Tikuisis, P; Kane, DM; McLellan, TM; Buick, F; Fairburn, SM. Journal of Applied Physiology. 1992, 72 (4): 1311-1319.
3. Z.M. Ao; J. Yang; S. Li; Q. Jiang. Chemical Physics Letters. 2008, 461(4-6), 276-279.

UV-Vis absorption spectrometry

a) CO has been reported in the literature to have absorptions from around 70nm to 200nm and shows various peaks and intensities. In general, these absorption spectrum was taken in the gas phase thus no solvents was used though the gas pressure of the absorption cell differs from case to case.

b) According to Myer and co-workers, CO has an absorption cross section value of near 5Mb at 107~108nm, several other peaks were also observed with absorption cross section value of 3Mb at around 150nm. Huffman and co-worker reported a relatively strong absorption peak at 79nm with an absorption coefficient value of near 1900cm-1 in the 60-100nm region.

4. R.E. Huffman, J.C. Larrabee, Y. Tanaka. Absorption Coefficients of Carbon Monoxide in the 1006-600-Å Wavelength Region. J. Chem. Phys. 1964, 40, 2261-2269.
5. J.A. Myer, J.A.R. Samson. Vacuum-Ultraviolet Absorption Cross Sections of CO, HCl, and ICN between 1050 and 2100 A. J. Chem. Phys. 1970, 52 (1), 266-271.
6. C. Letzelter, M. Eidelsberg, F. Rostas, J. Breton, B. Thieblemont. Photoabsorption and photodissociation cross sections of CO between 88.5 and 115 nm. Chem. Phys. 1987, 114, 273-288.
7. H. P. White, Xin-Min Hua, J. Caldwell, F. Z. Chen, D. L. Judge, C. Y. R. Wu. The Ultraviolet Absorption Spectrum of CO: Applications to Planetary Atmospheres. J. Geophys. Res. 1993, 98(3), 5491-5497.

Similar Analytical Problem
Lauren Sauer, "Vapor intrusion in buildings". Analyte type: Trichloroethylene and Tetrachloroethylene(Gas). Matrix type: Air (Gas). Relevance: Environmental, Health.

Studies that are similar will be the sampling of the air. Since the analyte's concentration is low, there might be extraction steps that will be alike.

Studies that are different: In my problem I might need to control the concentration of oxygen and look at the corresponding amount of CO in the exhaust. Her study would control the distance from the industrial plants where the air sample is taken.


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BLOG 2. How would you determine molar absorbtivity (question 3b)? (-0.15 pt)

Question 6 - Posting in Lauren's entry? (-0.15 pt).

Revise grammar carefully before posting.

The hypothesis needs minor changes. Revise. Avoid mentioning the measurement component: "which can be collected and be analyzed in order to find the concentration of CO per volume". Include the concept: " This value can further be used to estimate if the toxicity of the exhaust of the fuel" in your hypothesis.