Volatiles Screening and Quantitation

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Blood alcohol screening

Blood alcohol content (BAC) analysis is one of the most common preliminary tests in forensic science. For law enforcement purposes, blood alcohol content is used to define the level of intoxication and serves as a rough measure of impairment. It is generally performed via headspace gas chromatography (GC) with a flame ionization detector (FID), using dual-column/dual-detector configuration for compounds identification confirmation.

 

The content of alcohol in blood is most commonly expressed as grams per deciliter (g/dL). Find out how to determine blood alcohol levels using the Thermo Scientific TRACE 1600 Series GC, Thermo Scientific TriPlus 500 GC Headspace Autosampler, and Thermo Scientific Chromeleon Chromatography Data System (CDS) Software solutions.

BAC analysis workflow

Sample collection

Blood is collected by a phlebotomist in two grey-top tubes that should contain a preservative and anticoagulant (grey top tubes are normally used in medicine for glucose-testing). Typically, sodium fluoride is used as a preservative. One tube is for the crime lab to test, and the other is preserved for the subject’s independent testing purposes. At the crime lab, one tube is opened, and the contents are poured into a clean container. A measured amount of blood and a type of alcohol (usually n-propanol) as internal standard are mixed together into a headspace vial, which is then crimp-sealed.

 

The number of samples run in a day by a forensic lab includes specimen and quality control standards that can easily reach several hundreds. Sample preparation often accounts for more than twice the time spent on actual chromatography. Through headspace sampling, it is possible to automate and accelerate organic volatiles determinations to increase sample turnaround and lower the cost per analysis. It is paramount that the system will be able to run many unattended analyses and safely classify and store results.

TriPlus 500 GC Headspace Autosampler

The Thermo Scientific TriPlus 500 GC Headspace Autosampler is designed for fast startup, high productivity, and maximum flexibility for any lab analyzing organic volatiles.

  • Superior sample integrity and traceability 
  • End-to-end inertness of the sample path with direct column connection to the valve and loop manifold 
  • Compact design easily upgradable from 12-vial basic configuration up to 240-vial capacity 
  • Local control through the friendly GC touchscreen user interface further enhances the system's versatility

TriPlus RSH SMART Autosampler

With its advanced, built-in robotics, the Thermo Scientific TriPlus RSH SMART Autosampler delivers exceptional sample handling flexibility, and reliable, weekend-long unattended operation. Ideal for high throughput labs requiring versatile sample injection capability.

  • Gas-tight syringe assures reliable direct headspace injection
  • Overlapping sample incubation capability allows higher productivity
  • Accommodates up to 300 vials facilitating high throughput need for the lab
  • Automatic Tool Change to automatically switch between liquid, headspace and SPME injection techniques

GC headspace
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GC Headspace

Blood is a very complex biological matrix, which includes salts, proteins, lipids, and other metabolites. As such, a direct analysis of blood would result in very frequent contamination of the GC injector, leading to frequent stops in the working routines and as such very low efficiency. Headspace sampling technique facilitates the extraction of volatiles and provides a “clean” injection in the GC system leading to minimized instrument downtime and overall short time of analysis.

 

Typical screening for blood alcohol is done with static headspace extraction coupled with a gas chromatograph in a dual-column/dual-FID configuration. A short uncoated guard column connects, through a 3-port microfluidic connector, to two columns having different polarity, to combine quantitative determination with ID confirmation.

Thermo Scientific TriPlus 500 HS – TRACE 1610 GC

  • Compact design with direct column connection
  • Full upgradability from 12-vial up to 240-vial capacity
  • Touch screen interface provides instant access and control of the HS-GC system
  • Multi-language capabilities
  • Easy method development
  • Sample traceability with barcode reading capability

Thermo Scientific TriPlus 500 HS – ISQ 7610 Single Quadrupole GC-MS

  • Expand analytical determination of volatiles in blood
  • Robust, reliable solution to meet lab productivity needs
  • Extended dynamic range to handle wide concentration range

Simplify your analysis to just a few mouse clicks without sacrificing flexibility using Chromeleon Chromatography Data System Software. Quick, efficient peak integration with dynamic data linkage and traceability to maintain steady tracking of data at any point during processing.

 

Chromeleon Software benefits:

  • Dynamic linking of all data, from calibration plots to report tables and charts
  • Compliance-ready data management
  • Complete multi-user chromatography management solution
  • Robust and secure file access and storage

Chromeleon CDS

Learn how to streamline your laboratory workflow with operational simplicity and intelligent functionality. The Chromeleon CDS is the first chromatography data system to include quantitative mass spectrometry controls and processing in a client/server environment.

For Research Use Only. Not for use in diagnostic procedures.