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1619870 
Journal Article 
Determination of Acetaldehyde and Acetone by the Iodoform Reaction Determination of 1,2-Propylene Glycol 
Dalnogare, S; Norris, TO; Mitchell J Jr 
1951 
Yes 
Analytical Chemistry
ISSN: 0003-2700
EISSN: 1520-6882 
NIOSH/00130175 
23 
10 
1473-1478 
A method utilizing ultraviolet absorption and the iodoform reaction was developed to determine quantities of acetaldehyde (75070) or acetone (67641) less than 0.5 milligrams (mg). Iodoform was produced by adding 1 to 5 milliliters (ml) of sample to 10ml to 20 percent iodine and 3.3ml 20 percent sodium-hydroxide. The iodoform was then extracted with chloroform, the absorbancy of the extract at 347 millimicrons (mmicrons) was measured, and the amount of acetone or acetaldehyde was calculated. Possible interference by ketones, aldehydes, and alcohols at 347mmicrons was assessed. Sample concentration, reaction time, temperature of the hypoiodite solution, and the order of addition of reagents were varied to determine their importance in the yield of iodoform obtained. Prepared samples of about 0.04 to 0.45mg acetone in cyclohexanol were analyzed, and results were compared with those calculated from standard calibration curves. Prepared samples of 0.08 to 0.52mg 1,2-propylene-glycol (57556), alone or with ethylene-glycol (107211), were analyzed by first oxidizing the glycol to acetaldehyde. Interfering effects were produced by less than 0.03mg methyl-isopropyl-ketone, mesityl-oxide, and aldol, and less than 1mg isobutyraldehyde, isopropyl-alcohol, and sec-butyl-alcohol. Maximum iodoform yields of 58 percent for acetaldehyde and 108.6 percent for acetone were obtained by adding the reagents in the order of alkali, then iodine, then sample, and by using 1500 to 2100 equivalents of iodine per mole of acetaldehyde or acetone and holding the alkali equivalent to the iodine present. Iodoform yield was not affected by other factors tested. Determinations of acetone in cyclohexanol differed by only 0.002 to 0.005mg from calculated values. Analysis of prepared samples of 1,2-propylene-glycol in ethylene-glycol yielded recovery rates of 80.7 to 105.6 percent. The authors conclude that the method can be widely applied to the analysis of compounds capable of reacting with hypoiodite to give iodoform. 
DCN-118675; Chemical analysis; Absorption rates; Chemical properties; Ultraviolet spectrometry; Analytical methods; Qualitative analysis; Organic solvents; Aldehydes; Laboratory testing