Blood Alcohol Components (BAC) Analysis by Headspace–Gas Chromatography

Headspace–gas chromatography (HS–GC) is the analytical instrumentation utilized for the analysis of blood alcohol components (BAC) in biological fluids. Accuracy and precision are essential in analysis involving legal matters. Speed of analysis, sample throughput, and cost efficiency are additional concerns with high throughput laboratories.

Using the paired columns of DB-Alc1 and DB-Alc2, the factor limiting throughput is the elution of the internal standard component. Using n-propanol as the internal standard, the final peak elutes around 1.5 min on DB-Alc2 with 1.2 µm stationary film thickness. Restek offers RTx-BAC Plus 2 with a 0.6 µm stationary film thickness. This reduced film allows faster analysis while maintaining resolution requirements. With this faster analysis, using H₂ carrier, both column run times can be reduced to under 1.0 min for higher throughput.

• Headspace extraction allows for minimal sample preparation, a high degree of automation, highly reproducible results that are essential in high case load laboratories.

• Fast separation in less than 1.0–1.5 min allows for high throughput.

• The Dani Master SHS Static Headspace Sampler performed well as tested and offers large 120 vial autosampler tray capacity for high throughput of 900 samples per day.

• Bar code reading of vials insures sample integrity and chain of custody from vial to report.

• The largest number of headspace systems in the world are manufactured by Dani Instruments.

Conclusion

The Dani Master SHS Static Headspace Sampler coupled with the Dani Master GC Gas Chromatograph as tested permits BAC analysis of ethanol and internal standard in less than 90 s with He carrier. Proper selection of column and the use of t-butanol as the internal standard can reduce the analysis time to 1 min. Linearity of 7-point calibration curve from 0.005–0.5% ethanol was 0.9997 with < 1.2% RSD for five injections at 0.08% ethanol.

The system offers a fast, reliable and economical solution to the analysis of ethanol in bodily fluids. Dani is the largest manufacturer of headspace samplers in the world and is expanding in the USA market in calendar year 2017.

References

(1) D.S. Christmore, R.C. Kelly, and L.A. Doshier, J. Forensic Sci. 29(4), 1038–1044 (1984).

(2) B. Kolb and L.S. Ettre, Static Headspace-Gas Chromatography: Theory and Practice, 2nd Edition (John Wiley & Sons, Inc., 2006).

To read the full version of this application note, please visit: https://dani-instruments.com/download/an_167_analysis-of-ethanol-in-blood-using-staic-headspace-sampler-master-shs-and-master-gc/

DANI Instruments, Inc.
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Website: www.dani-instruments.com