Manual versus automatic sampling variations of a preliminary alcohol screening device

Area of Science:

• Forensic Toxicology
• Analytical Chemistry
• Human Physiology

Background:

• The Alco-Sensor IV Black Dot Model's manual sampling function may underestimate breath alcohol content (BrAC).
• Understanding potential discrepancies between manual and automatic breath sampling is crucial for accurate alcohol level determination.

Purpose of the Study:

• To compare breath alcohol content (BrAC) measurements obtained via automatic sampling versus three distinct manual sampling techniques.
• To quantify the underestimation of BrAC when using manual sampling methods.

Main Methods:

• A controlled human subject study involving alcohol consumption (vodka and orange juice).
• Breath alcohol content (BrAC) measurements were taken during the descending limb of the BrAC curve.
• Comparison of results from the standard automatic sampling technique against three manual techniques.

Main Results:

• Statistically significant differences were observed between automatic and manual sampling techniques.
• All three manual techniques consistently underestimated BrAC compared to the automatic method.
• Average maximum underestimation was 27.9% (median 27.7%), ranging from 20.8% to 40.0%.

Conclusions:

• Manual sampling techniques in the Alco-Sensor IV Black Dot Model can lead to significant underestimation of true breath alcohol content (BrAC).
• The findings highlight potential inaccuracies in roadside or evidential testing if manual sampling is employed.