edlted by
thumbnail ~ketchef Detection of Carbon Monoxide in Tobacco Smoke Using Molybdosilicate H. I. Feinsteln 10411 Forest Avenue Fairlax. VA 22030
During World War I1 a simple, rapid, and extremely sensitive test was developed at the National Bureau of Standards for the detection of small concentrations of carhon monoxide around military equipment. It is so sensitive that it is also possible to test exhaled air to diagnose carbon monoxide poisoning without using a blood sample.' The presence of carbon monoxide in tobacco smoke using this procedure was demonstrated by the late Martin Shepherd before the members of the Chemistry Division. The test could be oerformed when studying . .the chemistry of carbon monoxide or air pollution. The test is based upon the reduction of molyhdosilicate by carbon monoxide in the presence of palladium (11) sulfate catalvst. Molybdenum(V1) in molybdosilicic acid, Ha[Si( M O ~ O ~ is-more ) ~ ] , readily reduced than normal molybdic acid."n the test, the yellow molybdosilicate-palladium sulfate complex is converted to a green or bluish-green product probably containing "molybdenum blue." The latter is a mixture of varying proportions of Mo(V) and Mo(V1) oxides such as MosOs' and Mo4OIl2.The oxidation number of molybdenum is between 5+ and 6+.
' Shepherd. M.. Anal. Chem.. I.E.C.. 19. 77 (1947).
2 Feigl.
F., "Spot Tests," Vol. 1, Inorganic Applications. 4th English Ed.. Elsevier. New York, 1954, p. 334. Mine Safety Appliances Co.. Malvern. PA 19355. Catalog NO.
MARYVIRGINIA ORNA.0 S U College of New Rochelle New Rochelle. NY 10801
p r e p a r d t u b e s are available commercially a t a cost of $14.30112 tubes.3 A demonstration using one tube costs a few cents per student. Since it is such an impressive demonstration of the presence of CO in tobacco smoke, the cost per student is nominal. In use, the tips of a tube are cut off. Several mouthfuls of tobacco smoke are blown through the tube. The presence of CO is indicated by a change in color from yellow to bluishereen. Tests may be made with small amounts of other reducing eases and vavors. Asvirator bulbs should he used and n e a t care (!) exercised. Brief descriptions of phenomena, topics, facts, etc., which chemical e d m t w s have fwnd to be of interest in h i r teachino, will be ~resentsd
Mary Vlrglnla Orna. O.S.U. is Professor of Chemistry at the College of New Rochelle. She received her doctorate in analytical chemistry from Fordham University in 1962 and taught at hAcademy of Mt. St. Ursula in the Bronx before joining the New Rochelle faculty in 1966. Dr. Orna is a very active member of the ACS and DIVCHED. She has been respon' slble for organizing symposiums on color technology and interdisciplinary approaches t~ to chemical education. She also serves on Me Subcomminee far the 1961 ACS General Chemistry Examination and DIVCHED's Personnel and Naninations CommiUee. As a hobby. she enjoys constructing crossword puzzles and has been a contributor to SciOuesf and the daily and Sunday New York Times.
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Volume 58
Number 8
August
1981
633
