TESTS FOR ALCOHOL IN BREATH AND BLOOD JAMES M. BERKEBILE McPherson College, McPherson, Kansas
A CRITICAL
factor in law enforcement, attempting to a demonstration of its assembly and use. A diagramkeep intoxicated drivers off the highway, is to obtain matic sketch is given for the assembled device. The conviction of the offender when he is apprehended. I t court record before this time was not too favorable, is well known that many law violators escape the due owing to the usual uncertain methods of interpreting penalty of law through the broad manner in which the ohjective symptoms of intoxication. One great judges and juries interpret the visible evidences of value has been the immediate release of drivers by the intoxication. As a result there is a persistent and officerswhere the Intoximeter test gave no evidence of flagrant disregard for the law in this respect, cnlminat- thesubject's being under the influence of alcohol. Other ing in a marked rise in highway fatalities due to drivers charges, usually of lesser import, are made where operating under the influence of alcohol. evidence warrants it. Considerable research' has been conducted to deterWhere legislation haa been adopted, such as in Maine, mine the alcoholic content of body fluids with a view to Indiana, Oregon, and New York, the following pattern correlating these values with the body reactions result- is followed. Zone I: Where concentrations of 0.05 per ing in high accident rates on the highways. The cent or less alcohol are found in the blood there is prima alcohol content of the blood, breath, spinal fluid, urine, facie evidence that the driver is not under the influence, and saliva have been shown to give reliable measures of even though the studies indicate this favors the offender. the amount of alcohol in the brain a t the time the sample Zone 11: Where concentrations are from 0.05 to 0.15 was taken. Standardized measures of relative body per cent the evidence is considered relevant but not, control a t different concentrations of alcohol in the prima facie evidence that the driver was under the blood are now used in many states. The alcohol con- influence. A few of those having blood alcohol slightly tent of the breath, which is directly related to the alcohol above 0.05 per cent will be affected. Near 0.15 per cent content of the blood, is now easily obtained. A dirert all will be affected. Zone 111: An alcohol concentrablood sample of the subject under question can be run tion in the blood of 0.15 per cent or above is regarded as in any ordinary analytical laboratory. This paper prima facie evidence that the driver wasdefinitelyintoxiindicates two established procedures used for analysis cated. of the breath and the blood. Most college laboratories The National Safety Council Committee on Tests for are equipped to conduct the chemical analyses used in Intoxication4 reports experiments demonstrating that determining the alcohol content. of either of these two abstainers and moderate drinkers show the influence of body products. alcohol before a concentration of 0.05 per cent is Innumerable experiments have shown that the breath reached; even heavy drinkers, possessing the greatest provides a very convenient, readily obtainable, and tolerance to alcohol, show influence a t concentrations entirely reliable index of the alcoholic content of the between 0.07 and 0.09 per cent. Many authorities conblood.'. Results of these t,ests have now been sider 0.10 per cent concentration the upper limit of the accepted by courts across the land, even though range of zone 11. In the experience of the author, court specific legislation has not been enacted to provide for reports of the ohjective symptoms indicating intoxicathem. The McPherson city and McPherson County tion would bear out the validity of the 0.10 to 0.11 per law enforcement officers have used the "Into~imeter"~ cent upper limit for zone 11. and blood-sample method for almost one year; and I n using the convenient Intoximeter, the cardboard where a state of intoxication has been indicated by the carton is opened and the train assembled. The person standardized values, not one case in rourt has been lost. under question blows several liters of air, through the The intoximeter is a device simple in construction, mouthpiece, E, and the valve, D, into the balloon convenient to carry in the pocket of an overcoat or furnished with the equipment. The balloon, B, is then jacket, and can be operated by any person who has had connected to the device as shown in the sketch, and a portion of the breath-sample is allowed to flow through 1 FORRESTER, G. C., "The Use of Chemical Tests for Alcohol the glass containing an analytically deterin Traffic Law Enforcement," Charles C Thomas, Springfield, mined amount of acidified potassium permanganate Illinois, 1950. number seconds 9 Private commnnioation from Dr. C. W. ~ ~ ~~ i c hhi - solution. ~ b The ~ exact ~ ~ ~ of ~ , required for gan Department of Health, Crime Detection Laboratories, the permanganate solution to decolorize, with the Lansing 4, Michigan. Patented device by Dr. Glenn C. Forrester, Intoximeter Association, Niagara Falls, New York.
' National Safety Council: Committee on Tests for Intoxication Reports for 193&41 and their appended references.
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JULY, 1954
breath-sample flowing through it, gives the officer an immediate estimate of the state of intoxication. If the number of seconds required is 30 or less the man is nndoubtedly under the influence. If the time required is more than 80 seconds the officer can rest assured that the difficulty is not due to a state of intoxication. The permanganate solution is retained in the fritted glass area labeled P. To retain a permanent record of the breath-sample the remainder of the hreath is allowed to flow through the chemical train by removing the cap, C, on the Ascarite tube. Tube M contains pure magnesium perchlorate which takes up all the water and alcohol in the breath-sample. The previously weighed tube A contains Ascarite which removes the carhon dioxide of the same sample. It is customary for law enforcement officers to have the chemist weigh all Ascarite bulbs before the Intoximeters are used. They are then repacked and sealed for the officers. If this is not done, the only reliable record of the case is the observation of the officer on the time of the oxidation by the permanganate solution. If the chemist's analysis on the exact percentage of alcohol is desired for court proceedings the used Intoximeter is submitted for determination of the alcohol and carbon dioxide content of the breath-sample. The weight of the carbon dioxide in the breathsample is determined by reweighing the Ascarite tuhe after use. An analytical balance is used for this purpose. The amount of alcohol in the magnesium perchlorate tuhe is determined as follows: The perchlorate is washed from the tube into a 250-ml. round-bottom flask with approximately 50 ml. of water. Distillation of the sample is conducted in a distillation apparatus equipped with ground-glass joints. The receiver is a 25-ml. graduated flask. Approximately 25 ml. of distillate is collected at a moderate rate of distillation. All alcohol has been shown6to he removed from the dense salt solution with this quantity of distillate. A few drops of water are added to bring the volume of the flask to exactly 25 ml. Ten-milliliter samples are removed and oxidized with an excess of standard potassium dichromate in a hot acid medium. Back titration of the cooled diluted sample is conducted with sodium thiosulfate in the presence of an excess of K I using starch as an indicator. The amount of alcohol is determined in the 10-ml. sample by calculation. This value multiplied by two and one-half will give the total amount of alcohol present in the breath-sample. To determine the percentage of alcohol in the hlood one bases his calculations on the following reasoning: According to Henry's law the concentration of alcohol vapor in the alveolar air deep in the lungs is proportional to its concentration in the pulmonaly hlood. Alveolar air also has a constant content of carhon dioxide in the adult, approximately 5.5 per cent by volume. Therefore, if a sample of alveolar air is available for analysis the concentration of the alcohol in the hlood can he (indirectly) determined. Even though exhaled air from See footnote 2.
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the lungs is not alveolar air, the air which has not been deep in the lungs has picked up neither alcohol vapors nor carhon dioxide from the hlood. However, the ratio of alcohol to carbon dioxide remains the same. From the calculation of the carhon dioxide content of the breath, the relative proportion of alveolar air can he determined. Then from the quantity of carhon dioxide in the hreathaample and the amount of alcohol in the same sample the per cent of alcohol in the blood can he determined. Analyses of both hreath, by Intoximeter, and blood taken a t the same time indicate a correlation within 0.01 per cent between the direct and indirect methods.
It has been shown that 0.2 g. of carbon dioxide, equivalent to 2000 ml. of alveolar air, also expresses the percentage by weight of alcohol in the blood. Thus the calculation of the percentage of blood alcohol is obtained as follows: % blood alcohol
=
wt. alcohol in the total bbreath-sample X 100 wt. COz in the total breath-sample 0.200
+
Thus the exact percentage alcohol in the blood can he determined in order to substantiate the charges of officers or to indicate that the charge was erroneous on the basis of established standards. This serves as a protection to the innocent as well as holding the guilty to a strict account. If one receives a hlood sample, which any physician or nurse can obtain, it is quite simple to use a modification of the procedure given above to get the alcoholic content. Approximately 2 g. of blood accurately weighed is transferred to a 500-ml. flask with about 50 ml. of water. Ten grams of mercuric sulfate is added to reduce foaming. The collection and oxidation
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JOURNAL OF CHEMICAL EDUCATION
of the distillate are the same procedures as those used for the breath sample. The calnllation of the percentage of alcohol is quite easy: % blood alcohol =
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wt. of alcohol in total blood ample X 100 ..-+ 7"
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If law enforcement officers have the assistance of college personnel near by, it paves the way for easier
and more rapid indictment of the guilty and reliase of the innocent. I t would seem reasonable that chemists who are interested in contrihutine to the commnnit,~ ~ welfare would find familiarization-with these and likk procedures valuable. Community education t o the use of precise measures for intoxica&on, and the contribution of our time in a professional capacity for service t o orir society are obligations we should not avoid. ~
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