Gas Chromatography BAC Tests – Everything You Need to Know

gas chromatography bac tests

Gas Chromatography BAC Tests: Everything You Need to Know

Driving under the influence in Arizona can have an array of consequences. The most immediate one is a law enforcement professional requesting the submission of a chemical test. Through this test, the driver’s blood alcohol content will be established. A breath, urine or blood test can be performed. While breath tests are very common because of the ease of administration, a blood alcohol test may be chosen because it is perceived to be much more accurate. Blood BAC tests are known as gas chromatography BAC tests. This is how they take place.

What is a Gas Chromatography BAC Test?

The most important thing to understand is that gas chromatography BAC tests provide an indirect assessment of BAC. The machine itself does not examine the liquid that has been collected via the provision of a blood sample. Rather, substances are converted to gas and the different types of molecules from the sample are separated from each other.

After the separation is completed, microscopic samples get examined by the machine. In Arizona, the process is automated. This means that the separation and the analysis are “carried out” by the machine rather than by a lab technician.

In essence, the machine tests out various compounds that have been separated from the blood. The quantities are so small that they can’t be examined by the naked human eye. While the process is considered to be highly reliable, there could be some gas chromatography preparation issues that will alter the results and contribute to serious errors.

Issues That Contribute to Gas Chromatography Test Result Errors

The machine itself does what it has been designed to do. The taking and the preparation of blood samples, however, may contribute to a result that is not accurate.

For the gas chromatography test to work, blood has to be collected, stored and transferred in a specific way. Everything that occurs before the sample is placed in the gas chromatograph could affect the outcome of the test.

Problems with the collection of a blood sample include whether enough has been drawn, whether the right tube has been chosen and if the correct number of inversions has occurred. Something as simple as a labeling error could lead to a person who hasn’t consumed alcohol being charged with DUI.

Refrigerated samples will then have to be taken to the Arizona police lab. Because the gas chromatograph processes multiple samples, these are delivered to the lab in batches. Usually, anywhere between 30 and 40 blood samples will be taken to a police lab at the same time. During transportation, the integrity of the tubes may be affected.

Finally, the preparation of the sample before it gets put in the machine will potentially impact the test result. Pipetting is used to transfer some of the blood from the tube into a headspace vial. The technician could either pipet the blood directly or use a cuvette to simplify the process. The cuvette is a smaller container that is often utilized in lab procedures but it has to be properly sanitized in order to maintain the integrity of the sample. If the lab technician doesn’t sanitize the cuvette during the blood transfer, the sample will be compromised.

Challenging Gas Chromatography Test Results

gas chromatography bac testsAn experienced DUI attorney can challenge the gas chromatography BAC tests’ results by claiming that some of the mistakes mentioned above have been committed.

The calibration of the gas chromatograph itself and the reliability of the machine’s software may also be challenged in the event of test result accuracy suspicions.

In order for test results to be valid, both the quality of the machine and the work of the lab technician will have to be examined. These two work in conjunction and cannot be simply assumed. Just accepting the test results without challenging the process can have life-altering consequences. This is why you should definitely consult an Arizona DUI attorney who will acquaint themselves with the manner in which the test was carried out and the accuracy of the BAC result.