More on Breath Testing for Drugs – It is Coming

April 23rd, 2014 Allen Trapp Posted in Breath Tests, Driving under the Influence of Drugs, PBT's No Comments »

A roadside breath test for cocaine, marijuana, and other drugs may not have arrived in your state yet, but it is coming. Using a commercially available breath sampler, Swedish scientists were able to identify 12 drugs in the breath samples provided by at least 40 patients who had taken drugs in the previous 24 hours. However, all were probably hard core users because they were were recovering at a drug addiction emergency clinic.

This study is the first to detect alprazolam (the active ingredient in Xanax) and benzoylecgonine (an inactive metabolite of cocaine) in exhaled breath, according to a journal news release. Ths study confirms that diazepam (Valium), amphetamine, methamphetamine, morphine, and other substances can be detected in a person’s breath.

The author of the study emphasized that future studies should test the correlation between blood concentrations of drugs and the breath concentration. Currently, analysis of blood and urine samples is the most common method for detecting the presence of drugs and in the case of blood the concentration. However, advocates believe that breath test for drugs would be simpler, less invasive and easier to use in many locations, including roadside checks. Accuracy is another, and more important, factor.

Exhaled breath contains micro-particles that carry certain substances picked up from the fluid lining the airway. Any compound that has been inhaled or is present in the body can pass into the breath, where it can be detected. When a person breathes into the device, saliva and large particles are separated from the micro-particles that need to be measured. The micro-particles are deposited on a filter, which can then be sealed and stored until analysis is conducted using lab tests known as liquid chromatography and mass spectrometry.

Written by Allen Trapp who is board certified by the National College for DUI Defense and the author of Georgia DUI Survival Guide Visit Website
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More on PBT’s (Preliminary Breath Tests): The Alco-Sensor

August 13th, 2009 Allen Trapp Posted in Breath Tests, PBT's No Comments »

     Although a number of PBT’s are approved for use in Georgia, the most common is the Alco-Sensor IV, which is manufactured by Intoximeter, Inc.  This preliminary breath testing device employs a fuel cell technology that is not specific for ethyl alcohol.  Nevertheless, it is used by police as a “screening” device when making their DUI arrest decisions.

     An Alco-Sensor only captures one milliliter of breath.  It cannot be adjusted for a person’s actual blood-to-breath ratio, body temperature, or gender.  In addition, it does not have a “slope detector” to rule out errors from the suspect’s mouth alcohol.  When this preliminary breath testing device only captures one milliliter of breath and registers .08, the Alco-Sensor IV unit is analyzing .00000038 gram of ethanol, or .38 nanograms per milliliter.  One nanogram is the same as one part per per billion, so .38 is a little more than one-third of one part per billion. 

     Despite these shortcomings, some states have allowed an Alco-Sensor with an attached printer to serve as an evidential breath testing device.  After all, more admissible breath tests means more DUI convictions, and that is exactly what the neo-prohibition advocacy groups want – more convictions.  The Georgia courts, recognizing their limitations, have resisted the State’s efforts to introduce preliminary breath test results into evidence.  If the subject ever comes up, now you know why the Georgia courts are right.  

Written by Allen Trapp who is board certified by the National College for DUI Defense and the author of Georgia DUI Survival Guide Visit Website
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Portable Breath Test : the Alco-Sensor

August 6th, 2006 Allen Trapp Posted in Breath Tests, PBT's No Comments »

The PBT is recommended for use after the field sobriety tests, although an officer will frequently employ before other FST’s, which fundamentally prejudices his evaluation of the other tests. Administration of the PBT after the other field sobriety tests (FST’s) also helps the officer comply with an industry recommended 15 minute deprivation time period. The Alcosensor IV operating manual specifically recommends a 15 minute waiting period. However, officers frequently ignore this recommendation and direct motorists to blow into a PBT before the administration of other FST’s.

In the 1980’s PBTs were (in many States) originally intended to be used after the FST’s to ensure the officer is working with an alcohol issue as opposed to drugs or a diabetic condition (Qualification not Quantification). Over the course of time in many states the PBT result has become admissible evidence (Qualification and now Quantification). But, the PBT is not accurate for determining BrAC. Carry over effect, lack of mouth alcohol detection, improper deprivation period, lack of calibration maintenance, and fuel cell maintenance are some of the top issues in cases involving a PBT. On the Alcosensor, the calibration adjustment screw is exposed on the side of the unit and assessable to the operator. The unit even comes with its own mini screwdriver to adjust the value up or down. Georgia allows any police officer to administer a PBT, and any of them can adjust the calibration of a PBT.

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