VASE™ provides superior headspace analysis by GC-MS for hundreds of applications by using vacuum and high phase ratios to maximize recoveries while minimizing matrix effects.
Clinical and Diagnostic
Pharmaceuticals, Nutraceuticals, Therapeutics
Food & Beverage
Cosmetics, Soaps, Fragrances
Materials and Consumer Product Testing
Ecosystems, Atmospheric and Biochemical Analysis
Introducing VASE - Vacuum Assisted Sorbent Extraction - What is it
Vacuum Assisted Sorbent Extraction (VASE) is a next generation extraction technique capable of greatly extending the range of extractable compounds over other headspace or even full immersion techniques. Virtually all liquid and solid samples to be analyzed by GC or GCMS are compatible with this exciting technique that was recently made even better by modifying the presentation of the Sorbent Pen to the vacuum headspace that completely prevents the deposition of aerosols on the outside of the Sorbent Pen during rapid agitation. Aerosol contamination is a known issue with HSSPME and other headspace techniques where splashing of the sample can lead to the deposition of non-volatile compounds on the extraction device, shorting the lifetime of these devices and increasing the production of thermal breakdown products that can be hard to distinguish from compounds that were actually in the original sample.
VASE is performed under vacuum which allows compounds to migrate much faster to the extraction device positioned only a few centimeters away, and the tremendous increase in phase over HS- SPME (>100,000x increase in surface area over a PDMS fiber) can virtually eliminate matrix affects thereby dramatically improving sensitivity and extraction reproducibility. Due to the consistency of the VASE technique, multiple Sorbent Pens can be used to extract several samples in parallel to increase the sample throughput with very little “Pen to Pen” variability in the results. Sorbent Pens with 1, 2, or 3 sorbent beds are available based on the desired boiling point range to be recovered, and custom sorbent packings are also available upon request. Analysis of the Sorbent Pen extracts are performed using the 5800 Sorbent Pen Desorption Unit (5800 SPDU), which provides multiple desorption options including SPLIT, SPLITLESS, and SPLITLESS VOC modes to optimize the recovery of compounds of interest.
A More Quantitative Alternative to SPME & SBSE
VASE offers tremendous advantages over other extraction techniques that perform extractions at atmospheric pressure, where diffusion rates are suppressed. Sorbent Pens™ perform sample enrichment offline from a GC-MS, allowing all samples to extract simultaneously and for longer periods of time. This approach results in high throughput while yielding a more complete and reproducible extraction for more sensitive and quantitative measurements. The low cost 5800 Sorbent Pen™ Desorption Unit (5800A SPDU) makes this exciting new technique both affordable and practical for virtually any laboratory’s budget. Upgrade to 120 sample automation with the Entech SPR40 (Sample Preparation Rail) Autosampler for the ultimate in laboratory productivity. Join the Sorbent Pen™ movement and take advantage of the next generation in GC-MS sample prep!
VASE provides considerable advantages over SPME, HSSE, SBSE and Dynamic Headspace
We apologize in advance for the bullet point overload, but we promise it’s not just us being trigger-happy with the keyboard. Our technology is just that good!
VASE utilizes a specialized sample enrichment device called a Sorbent Pen™.
Extensive Number of Applications
The list of VASE applications is extensive. The presence of a vacuum increases the rate of evolution of volatiles out of materials at lower temperatures, and depending on the matrix or sample surface area, extraction times can be as short as 2-5 minutes. VASE is particularly useful for the extraction of volatile and semi-volatile organic compounds from environmental, food, and biological samples. It has found applications in the analysis of flavors and fragrances, food safety, and food fraud detection, among many others. VASE has also been applied in the analysis of complex mixtures, such as essential oils and petroleum products.
Extreme Precision, By Design
VASE provides incredibly reproducible results by eliminating the inconsistencies inherent in other extraction technologies. Your state-of-the-art MS with 1-3% reproducibility can become a slot machine without proper sample preparation and extraction. Entech Sorbent Pens and VASE extraction technology eliminate the variables that have plagued gas chromatographers for decades.
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How it Works
Sorbent Pens can be used literally hundreds of times to perform VASE extractions. To perform VASE, a sample is weighed or measured into a 20, 40, or 125mL vial, a vacuum sleeve is secured to the vial using a high temperature plastic cap, and a Sorbent Pen is inserted with 1 or more sorbents depending on compounds of interest. However, since compounds cannot “break through”” the sorbent during extraction in the closed system created by the VASE process, even a moderate strength sorbent such as Tenax TA can recover much lighter compounds than is possible with dynamic headspace techniques. The Pen/Vial combination is then evacuated for 15-20 seconds to the boiling point of water at 25° C (0.3 psia, or 2KPa). The evacuated assemblies are placed into trays where they are heated and agitated using the 5600 Sorbent Pen Extraction System. After an extraction period of 0.1-16 hours, the Pen/Vial assemblies are removed and placed into a cold tray to quickly withdraw any moisture that partitioned into the Sorbent Pens during extraction. As the assemblies are still under vacuum, the transfer of moisture to the chilled vials occurs in just 10-20 minutes. After isolation into the Sorbent Pen sleeves, the Pens are thermally desorbed into a GCMS using the 5800 Sorbent Pen Desorption Unit. The deposition of compounds near the entrance of the Pens not only leads to a fast delivery to the GC column(s) with less thermal decomposition, but also typically eliminates the need for additional cleaning of the Pens prior to reuse. A 3801A Thermal Conditioner can clean Pens when they are severely overloaded, or before initial use.