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Submitted By kiannalaing
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Analysis of Blood Alcohol by Gas-Liquid Chromatography Virtual Lab Respectfully Submitted to the Forensic Science Department

Abstract The researchers experiment was about the police officers investigation on whether or not John Johnson who had initially been pulled over after being seen crossing the double line on a crowded highway. Johnson was pulled over and alcohol was detected. The officers tested Johnson for alcohol with two field sobriety tests. Which involve standing on one foot for thirty seconds and walking in a straight line heel-to-toe. Johnson failed both tests which led for his blood samples to be tested and his blood alcohol content to be investigated. The researcher found that Johnson was indeed intoxicated and had an EA area of 191 with a peak of 1.7, and PA area of 312 with a peak of 3.2 in the unknown blood. In standard 1 the PA area was 298 with a peak of 3.2. In standard 2 the EA area 82 had a peak of 1.7 while the PA area of 297 had a peak of 3.2. Finally in the researcher’s standard 3 the EA area was 272 with a peak of 1.7 and a PA area of 319 with a peak of 3.2.

Table of Contents

Introduction Pre-Lab Questions Materials and Methods Results Discussion Conclusion Appendix References

The researchers experiment involved the testing of a suspected drunk driver’s blood alcohol context. Once the sample was taken to the hospital the researchers used a Blood Alcohol by Gas- Liquid Chromatography using an internal standard to test it. Gas chromatography is a process by which a mixture of compounds in volatilized form may be separated into its constituent parts by moving a mobile (gas) phase over a stationary phase (sorbent or liquid phase). The progress of each component through a column is decreased in proportion to the component's affinity for the stationary phase. Each component is detected as it emerges from the column by a flame ionization detector. The components can be identified by their characteristic time required for emergence (retention time) and quantities by determining the ratio of the detector signal strength for the component to the signal strength for a reference compound (internal standard). (Angelos, 2010)
In the researchers experiment the researcher applied gas chromatography to the separation of a water-ethanol mixture.
This method is often used in the determination of alcohol (i.e. ethanol) in blood or urine. One obvious application is when law enforcement agencies need to determine whether or
Not someone is inebriated. In these cases, high sensitivity is required since 0.1% blood alcohol
Content is considered to be legally intoxicated in most states. The researchers own determination dealt with higher concentrations (up to 25% by volume) which are more typical of alcohol levels
Found in many alcoholic beverages. (Angelos, 2010)
Gas chromatography is a powerful and widely used tool for the separation, identification
And quantization of components in a mixture. In this technique, a sample is converted to the
Vapor state and a flowing stream of carrier gas (often helium or nitrogen) sweeps the sample into
A thermally-controlled column. (Jain, 1971) The analysis of blood and other body fluids for alcohol is most commonly performed using headspace gas chromatography due to its simplicity and the number of samples that normally run daily. The quality of GC results depends on many factors, including the stability of the gas chromatograph, the ruggedness of the injection system, and the sensitivity of the detector. Within this process, sample preparation and introduction provide the foundation for repeatability and reliability that are essential for the generation of quality data. Robustness and easy maintenance are also paramount to ensure continuous operation. (Gemme, 2012)
In the case of gas-liquid chromatography, the…