Answer :
A d) Flame ionization detector is the most commonly used gas chromatograph detector for the presence of alcohol in blood because of its large dynamic range.
- Gas Chromatography (GC) involves separating chemical mixtures to identify their components. An essential part of GC is the detector, which identifies and quantifies the chemical compounds separated by the chromatograph.
- Flame Ionization Detector (FID) is one of the most widely used detectors in gas chromatography. It is particularly common in the measurement of organic compounds, including alcohol.
- Dynamic Range refers to the range over which the detector can accurately measure the concentration of chemical components. A large dynamic range is beneficial because it allows for the detection of both high and low concentrations without needing adjustments.
- FID is favored in detecting alcohol in blood because it offers a wide linear range and high sensitivity for hydrocarbons, with characteristics like a low detection limit and reliability across varying concentrations, making quantitative work easier.
- Other Detectors: Although mass spectrometers (c), infrared spectrometers (b), and X-ray fluorescence detectors (a) are used for different applications, they might not provide the same combination of sensitivity, linear range, and ease-of-use for detecting alcohol in blood as the FID does.
In conclusion, the Flame Ionization Detector (FID) is the most commonly used gas chromatograph detector for the presence of alcohol in blood due to its large dynamic range and other favorable characteristics.
