Blood samples are analyzed for alcohol content using a Gas Chromatography.? More specifically, it is a?Head Space Gas Chromatograph with Flame Ionization Detector.

The Good & The Bad

The good thing about them is that they can be reliable if the test procedure is followed and the machine is probably maintained.

The bad thing about them is that they can be reliable?only?if the test procedure is followed and the machine is probably maintained.

Many people, including criminal defense attorneys, think that a blood test is better and more reliable.? This isn?t true.? Calling it a ?blood test? isn?t even very accurate.? The blood is heated up and then the air above the blood is tested for alcohol concentration.? The same issues that arise with temperature, calibration and human error with the breath test machine apply to a blood test.

Clinical Tests Comparing Blood & Breath Results

It probably comes as no surprise to you that clinical tests involving the taken of a person?s breath sample and blood sample results in the conclusion of different blood alcohol contents.? Jones, A. W., et al. ?Measuring ethanol in blood and breath for legal purposes: variability between laboratories and between breath-test instruments.??Clinical Chemistry?38.5 (1992): 743-747.