Which two analytical techniques does the EC/IR II employ to measure alcohol concentration?

Which two analytical techniques does the EC/IR II employ to measure alcohol concentration?

• A. Chromatography and Mass Spectrometry
• B. Infrared Energy Absorption and UV-Vis Spectroscopy
• C. Electrochemical Fuel Cell and Infrared Energy Absorption
• D. Ion Mobility Spectrometry and Flame Ionization

Answer: (C)

The EC/IR II uses two independent measurement methods: infrared energy absorption and an electrochemical fuel cell sensor. Infrared energy absorption works by directing IR light through the breath sample. Ethanol molecules absorb light at specific wavelengths, so the amount of light that makes it through is reduced in proportion to the ethanol present. The device translates that absorption into a breath alcohol concentration reading, relying on the relationship between absorbance and concentration. The electrochemical fuel cell sensor provides a second, independent measurement. As the breath passes over the fuel cell, ethanol is oxidized at the electrode, producing a current. The magnitude of that current is proportional to the amount of ethanol in the sample, giving another BrAC estimate. Using both methods together makes the measurement more reliable and helps guard against interference. Other techniques listed aren’t used by this instrument: chromatography/mass spectrometry, UV-Vis spectroscopy, and ion mobility or flame ionization detectors are different analytical approaches not employed by the EC/IR II.

The EC/IR II uses two independent measurement methods: infrared energy absorption and an electrochemical fuel cell sensor.

Infrared energy absorption works by directing IR light through the breath sample. Ethanol molecules absorb light at specific wavelengths, so the amount of light that makes it through is reduced in proportion to the ethanol present. The device translates that absorption into a breath alcohol concentration reading, relying on the relationship between absorbance and concentration.

The electrochemical fuel cell sensor provides a second, independent measurement. As the breath passes over the fuel cell, ethanol is oxidized at the electrode, producing a current. The magnitude of that current is proportional to the amount of ethanol in the sample, giving another BrAC estimate.

Using both methods together makes the measurement more reliable and helps guard against interference.

Other techniques listed aren’t used by this instrument: chromatography/mass spectrometry, UV-Vis spectroscopy, and ion mobility or flame ionization detectors are different analytical approaches not employed by the EC/IR II.