Evaluation of breath alcohol instruments. I. In vitro experiments with alcolmeter pocket model

Area of Science:

• Analytical Chemistry
• Forensic Science
• Biomedical Engineering

Background:

• Breath alcohol testing is crucial for law enforcement and medical diagnostics.
• Electrochemical fuel cell devices offer a portable solution for ethanol analysis.
• Accurate and reliable breathalyzer technology is essential for public safety.

Purpose of the Study:

• To evaluate the performance of the Alcolmeter Pocket Model breath alcohol device.
• To assess its accuracy, linearity, and stability under in vitro conditions.
• To determine its suitability for reliable ethanol concentration measurement.

Main Methods:

• In vitro evaluation of the Alcolmeter Pocket Model using an electrochemical fuel cell principle.
• Testing response to various alcohol vapors (ethanol, acetaldehyde, methanol, isopropanol, n-propanol) and acetone.
• Assessing linearity and accuracy across different ethanol concentrations (0-2.0 mg/ml).
• Monitoring calibration stability over an 18-day period.

Main Results:

• The device showed linear response to ethanol up to 1.0 mg/ml, with curvilinear response at higher concentrations.
• It responded to other alcohols but was insensitive to acetone.
• Standard deviation for ethanol determination was +/-0.0175 mg/ml at 0.902 mg/ml.
• Percent recovery ranged from 96.8% to 88.3% at tested concentrations.
• Calibration drift was observed at 0.01 mg/ml per week.

Conclusions:

• The Alcolmeter Pocket Model is a reliable breath alcohol device for concentrations up to 1.0 mg/ml.
• Potential cross-reactivity with other alcohols should be considered.
• The device exhibits acceptable accuracy and stability for practical applications, with minor calibration drift noted.