Flash-VASE™ provides for precise analysis of VOCs & SVOCs in matrices with low volatility.
Compare All Sorbent Pen Extraction Techniques For Complete Coverage of VOC to SVOC Analysis Of Virtually Any Matrix
| Label | Vase | R-Vase | F-Vase | Feve | LVSH |
|---|---|---|---|---|---|
 |  |  |  |  | |
LABEL | VASE | MA-VASE | Flash-VASE | FEVE | LVSH/X-LVSH |
Full Name | Vacuum Assisted Sorbent Extraction | Matrix Accelerated VASE | Flash-VASE | Full Evaporative Vacuum Extraction | (Extremely) Large Volume Static Headspace |
Sorbent Pen Type | HSP | HSP | FSP | FSP | ASP |
Vial Size | 20, 40, 125mL | 20, 40, 125mL, 1L | 2, 6, 20mL | 2, 6 mL | 250, 500, 1000mL |
When to Use | Liquid or Solid Sample Compositional Analysis. SPME Alternative | Faster VASE extraction when a volatile matrix is present, such as water or water/alcohol mixture | Samples with low volatile contents (solids, powders, Cannabis, packaging, oils) | Volatile Matrix with low solid contents (water, beverages, solvent extracts) | Measurement of equilibrated headspace to determine partition coefficients of aroma compounds. |
Extraction Technique | Vacuum, Diffusive, Closed System, Mechanical Agitation | Vacuum, Matrix Accelerated, Diffusive Closed System, Convective Agitation | Diffusive Vacuum Thermal Extraction, Closed System | Matrix Evaporative Transfer followed by Diffusive Extraction in Open System. Matrix eliminated | Dynamic, Fully equilibrated headspace, Static, Open System |
Vial Temp Range | 30° to 70° C | 30° to 150° C | 30° to 280° C | 30° to 280° C | 30° to 70° C |
BP Range | -50° to 450° C | -50° to 500° C | -50° to 550° C | 80° to 550° C | 0° to 450° C |
Water Management | Cold tray dehyd., Dry Purge, Split Inj. | Cold Tray Dehyd., Dry Purge, Split Inj. Capillary Focusing Trap | Cold tray dehyd., Dry Purge, Split Inj. | Vacuum Removal, Dry Purge | Dry Purge, Split |
Typical Pen Cycle Times | 200-2000 | 200-2000 | 200-1000 | 500-2000 | 100-200 (except not for disposible / replaceable inlet filter) |
Competitive Technologies Displaced | SPME, SPME Arrow, SPE, SBS | SPME / SPME Arrow, DHS | Micro Chamber, Direct Thermal Extraction, DHS | SBSE, Hi-Sorb, Full Immersion SPME | All other non-static, low sensitivity techniques |
Typical Sorbent Combinations | Tenax, Tenax / CPX, PDMS GB / Tenax, Tenax / Carboxen | Tenax, Tenax / CPX, PDMS GB / Tenax, Tenax / Carboxen | Tenax, Tenax / CPX, PDMS GB / Tenax, Tenax / Carboxen | PDMS / Tenax, Tenax / CPX | PDMS / Tenax, Tenax / Carbopack X |
Common Applications | Food, Beverage, Flavor, Aroma, Water, Soil, Consumer Products | Food, Beverage, Flavor, Aroma, Water, Soil, Consumer Products | Volatiles / Odors in Packaging, Polymers, Powders, Foams, Synthetics, Natural Products, Heavy Oils | SVOCs in Water, Flavors / Aromas in Thermally Labile samples, Pesticides in foods. | Aroma / Flavor Profiling |
Definitions:
Open System - Unretained compounds/gases allowed to pass through sorbent for removal by pump/vacuum.
Closed System - Completely isolated during extraction, so breakthrough of even the lightest compounds isn't possible. Allows recovery of wider boiling point range.
Flash-VASE. What Is It?
Flash-VASE is a next generation Thermal Extraction technique that places the sample in very close proximity to the collection sorbent, and uses static extraction under vacuum to more efficiently and completely recover volatile through semi-volatile compounds. Flash-VASE places the sample within 1-2 cm of the collection sorbent, with no flowing gases to heat up the sorbent during the extraction process like with dynamic headspace techniques, so the collected compounds stay optimally close to the front of the sorbent bed for very fast release to the GC. Extraction under a vacuum allows recovery of chemicals at a lower temperature, reducing or avoiding breakdown of the matrix itself. Flash-VASE has a tremendous number of advantages over other thermal extraction techniques, allowing Chemists to truly “See What’s Really There™”, in a way that keeps the analytical system clean and free from carryover.
Flash-VASE is intended for samples containing relatively low moisture levels, as the sample is heated anywhere from 30 °C to 280 °C while in a closed system, so the potential for generating a substantial amount of vapor during Thermal Extractions should be considered. However, some excess water can be temporarily delivered and condensed on the Sorbent Pen, as water can be removed after the extraction either by cooling the vial on a cold tray to pull water back down out of the Pens, or by placing a vacuum on the Pens after isolating them back into their sleeves to vacuum off the water prior to thermal desorption into a GCMS.
Flash-VASE utilizes a specialized sample enrichment device called a Sorbent Pen™.
Extreme Precision, By Design
Flash-VASE provides incredibly reproducible results, by eliminating the inconsistencies inherent in dynamically purged Thermal Extractions. Below is an example of 8 replicate Cannabis analyses for Monoterpene and Sesquiterpene profiling, and these 8 runs almost perfectly overlap. The Flash-VASE extraction times in these examples was just 5 minutes, at 100 °C. Higher temperatures will yield reproducible recovery of the Cannabinoids present in Cannabis.
Flash-VASE utilizing the Vacuum X-traction Bar (VXB)
The Vacuum X-traction Bar (VXB) supports sample extraction onto Sorbent Pens and the cleanup of Sorbent Pens and associated extraction hardware (sleeves, O-rings, etc). The VXB allows extractions to be performed in the sample preparation area, with only the extracts on Sorbent Pens brought into the GCMS laboratory. This is similar to how sample preparation techniques are currently performed, except the Entech vacuum extraction methods are easier, cleaner, and more sensitive, all without the use of hazardous solvents. he VXB comes in 30” and 50” sizes, allowing for convenient above the bench management of the Flash-VASE and Pen Evacuation Modules. Other modules may also be connected, such as the 3700 Thermal Vacuum Cleaning System, which is utilized to restore background-free extraction hardware before performing the next set of extractions.
The list of applications is quite extensive, and Flash-VASE can be scaled up to look at outgassing from larger samples as needed, such as in forensic investigations of accelerants in fire debris. Just as in VASE, 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, the extraction times can be as short as 2-5 minutes (Cannabis) by heating the sample to 100 – 200 °C under vacuum. This provides a whole new opportunity for high speed sample throughput for Flash-VASE compatible applications.
Sorbent Pen Options
Sorbent Pen Desorption and Analysis Solutions.
Flash-VASE Modules & Pumps
| Image (click to enlarge) | Part # | Description | Unit | link to product |
|---|---|---|---|---|
| VRES | Vial Heater Module, VASE Rail Extraction System, 120VAC/60Hz | EA | ||
| VRES-HV | Vial Heater Module, VASE Rail Extraction System, 240VAC/50Hz | EA | ||
| VRES-FVVM-2ML | 2mL vial Flash-VASE Vial Module | EA | ||
| VRES-FVVM-6ML | 6mL vial Flash-VASE Vial Module | EA | ||
| VRES-FVVM-20ML | 20mL vial Flash-VASE Vial Module | EA | ||
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10-20100 | 2-Stage Oilless Diaphragm Pump, Dual Voltage 120/240VAC, 50-60Hz | EA | Product Page |
Flash-VASE Extraction Vials, Sleeves, Components, and Accessories
| Image (click to enlarge) | Part # | Description | Unit | link to product |
|---|---|---|---|---|
| 2mL Flash-VASE Components | ||||
| VIAL-V002-11 | 2mL Clear Vials, wide mouth 11mm Crimp Top | 100pk | ||
| SP-VS011C | Vacuum Sleeve for 2 / 6mL Flash-VASE, EEU Module | 10pk | ||
| SP-11C-NUT | Securing Nut for 11mm Crimp Top Vial (2mL and 6mL) | 10pk | ||
| OR-L011S-30 | 2mL Vial Vacuum Sleeve Silicone O-rings | 30PK | ||
| 6mL Flash-VASE Components | ||||
| VIAL-V006-11 | 6mL Clear Flash-VASE Vials | 100pk | ||
| SP-VS011C-10 | Vacuum Sleeve for 2 and 6mL Flash-VASE Vials | 1 | ||
| SP-11C-NUT | Securing Nut for 11mm Crimp Top Vial (2mL and 6mL) | 1 | ||
| OR-L011S-30 | 6mL Vial Vacuum Sleeve Silicone O-rings | 30pk | ||
| 20mL Flash-VASE Components | ||||
| VIAL-V020-24 | 20mL x 24-400 Clear Screw Top Vial | 144pk | ||
| VIAL-V020-24-A | 20mL x 24-400 Amber Screw Top Vials | 144pk | ||
| SP-VSLL024-FV-10 | Flash-VASE Vacuum Sleeve for 20mL Vials | 10pk | ||
| FVASE-MCAP024-10 | Aluminum Caps for 20mL Vials | 10pk | ||
| OR-L024S-3 | Clean High Temp Silicone O-rings for 20mL vial Vac Sleeves | 30pk |
VXB - Vacuum X-traction Bars
| Image (click to enlarge) | Part # | Description | Unit | link to product |
|---|---|---|---|---|
 |
SP-VXB-50 | Vacuum X-traction Bar (50” VXB), allows 3-4 modules to be attached simultaneously | EA | Product Page |
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SP-VXB-30 | Vacuum X-traction Bar (30” VXB), allows 1-2 modules to be attached simultaneously | EA | Product Page |
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SP-VXB-PV-EVAC | Pen/Vial VXB Evacuation Module | EA | Product Page |
Cold Dehydration Tray and Accessories
| Image (click to enlarge) | Part # | Description | Unit | link to product |
|---|---|---|---|---|
| Water Management | ||||
| SP-HSCOLDTRAY45-FV | Flash-VASE Cold Tray for Dehydration of 15 each of 2, 6, 20mL Vial | EA | ||
Vial Platforms and Trays
| Image (click to enlarge) | Part # | Description | Unit | link to product |
|---|---|---|---|---|
|
SP-PF-TRAY10-20M | 10-Position Platform/Tray for VXB/SPR40, 20/40mL Vials | EA | Product Page |
Flash-VASE Controllers
| Image (click to enlarge) | Part # | Description | Unit | link to product |
|---|---|---|---|---|
| Supports Flash-VASE, 3700, & 3830 | ||||
| VXB-EMC-VASE-12 | VXB Mounted Dual Controller for Flash-VASE 1/2 with SPRINT Interface, 120VAC/60Hz | EA | ||
| VXB-EMC-VASE-12-H | VXB Mounted Dual Controller for Flash-VASE 1/2 with SPRINT Interface, 240VAC/50Hz | EA | ||
| VXB-EMC-VASE-34 | VXB Mounted Dual Controller for Flash-VASE 3/4 with SPRINT Interface, 120VAC/60Hz | EA | ||
| VXB-EMC-VASE-34-HV | VXB Mounted Dual Controller for Flash-VASE 3/4 with SPRINT Interface, 240VAC/50H | EA |
Replacement O-rings
| Image (click to enlarge) | Part # | Description | Unit | link to product |
|---|---|---|---|---|
| High-Temp O-rings (>180° C) | ||||
| SP-OR-1565S-30 | 2/6mL Vial Vacuum Sleeve Silicone O-rings | 30pk | Product Page | |
| SP-OR-L024S-30 | 20/40mL Vial Vacuum Sleeve Silicone O-rings | 30pk | Product Page | |
| Low Bleed O-rings (<180° C) | ||||
| SP-OR-1565F-30 | 2/6mL Vial Vacuum Sleeve FKM O-rings | 30pk | Product Page | |
| SP-OR60-L024-30 | 20/40mL Vial Vacuum Sleeve FKM O-rings | 30pk | Product Page |
| Methods | FLASH-VASE | Micro-Chamber Extraction | Direct Thermal Extraction/DHS |
|---|---|---|---|
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| Extraction System / Sample Prep | Glass Vials (2, 6, 20, or 40mL) are used as extraction chambers whereby samples are placed under vacuum to reduce required recovery temperatures, with subsequent heating of the vial from ambient up to 280 deg C to extract volatile to semi-volatile compounds | Microchamber thermal extraction is a sampling technique used to collect volatile and semi-volatile organic compounds (VOCs and SVOCs) released from products or materials. The technique involves using a compact unit with cylindrical chambers that can withstand temperatures up to 250°C. The released compounds are collected onto sorbent tubes for analysis by TD-GC-MS. | DTE (Direct Thermal Extraction) is a technique used to desorb volatile through semi-volatile compounds directly into a GCMS by placing the solid sample into a glass tube and using the GC carrier gas to thermally desorb the sample directly onto the GC column, with optional LN2 focusing |
| Extraction Technique | VASE- Vacuum Assisted Sorbent Extraction in a closed system. No breakthrough possible during sample heating | Flow through Dynamic Headspace in an “Open System”. Breakthrough of lighter compounds possible during sample heating while trapping the evolving compounds | The tube containing the sample is heated to release the analytes, which are then transferred to the GC column for separation and detection. |
| Water/Moisture Removal | After Extraction, the vial can be cooled to draw moisture back into vial, as typically there is little affinity of moisture to the sorbent. Only possible due to extraction in a “closed system”. Limiting moisture improves GCMS performance | Moisture must be purged through the sorbent, resulting in potential loss/breakthrough of lighter VOCs of interest | Split injection is the only means to limit the amount of water reaching the GCMS. Water may clog LN2 focuser if excessive. |
| Desorption System | Specialized Thermal Desorption System Installed Into GC. | Thermal Desorption System located next to the GC requiring the use of long transfer lines and potentially cold or focusing traps. | Extracted analytes are introduced into the GC column either by transfer from a cold trap or by direct injection |
| Injection Technique | Split or Splitless | Split or Splitless | Split or Splitless |
| Effective BP Range | -40C to 550C, depending on sorbents | Highly Dependent on Sorbents due to flow through trapping and further penetration of compounds into sorbents. Potential loss of compounds from sample to trap, through longer flow path | Recovery of compounds performed under pressure of carrier gas, which may limit diffusion of heavier compounds out of samples matrix. Recovery is matrix dependent. |
| Ad/Absorbent Phases | All phases, 1, 2, or 3 beds weak to strong. 2 Beds Typical | Activated Charcoal, Tenax TA, Carbopack X, and Porapak Q, among others (is this what they state on their website?) | No adsorbents used during Direct Thermal Extraction |
| Carry Over – Extraction System | Glass vials are low cost and disposable saving cleaning time. Vacuum sleeves (Sorbent/Vial interface) cleaned using specialized steam + dry cleaning in 1L vials under vacuum. | Microchamber must be thoroughly cleaned between sample analysis to avoid carryover. Substantially more surface area to clean up than other two techniques. | Residual analytes from previous samples can potentially contaminate subsequent samples, leading to false positives or inaccurate results. Careful cleaning of the DTE system and appropriate blank runs between samples can minimize carryover issues, but they still need to be considered when using this technique. |
| Carry Over – Adsorbent Traps | No active flow through traps, so compounds stay maximally close to trap entrance. More complete recovery during desorption, with far less carryover than Dynamic Headspace Sampling | Channeling into sorbent caused by inconsistency in sorbent packing due to expansion and contraction during heating and cooling cycles may require much longer bakeout times to totally remove chemical residual from last sampling event. This is inherent with most Dynamic Headspace sampling techniques | No adsorbent used |
| Distance to head of GC column from heated desorption point. | 1-2cm | Potentially meters long. | Direct GC Inlet. |
| Advantages of Flash-VASE & Other Key Differentials. | No Transfer Lines: Extracted sample is injected nearly at the head of the analytical column avoiding long transfer lines where losses and cross-contamination may occur.
Avoids channeling: Static vacuum extraction allows for a consistent and graduated deposition of analytes based on BP and size, eliminating issues with channeling which can cause losses of heavier compounds that find their way deeper into the adsorbent or potentially into a stronger bed where they may not come off. Reproducibility Issues: Vacuum eliminates “low flow dead volume” concerns found in other two techniques. The entire sample is exposed to the vacuum and heat equally |
Dynamic-Flow Conditions: The use of an extraction gas may cause heavier analytes to deposit deeper than desired in the sorbent trap and may also sweep heavy unwanted compounds onto the trap.
Long transfer lines used in the microchamber technique can cause issues with compound degradation or loss during transfer from the microchamber to the gas chromatography (GC) column. This is because the long transfer lines can cause some of the desorbed compounds to condense or react with the transfer line material or with other compounds in the sample matrix. Reproducibility Issues: Exposure to the extraction gas may vary based on the cell loading, and the consistency of sample particle size and shape. |
Matrix effects: Typically must heat the sample higher than other two techniques, as injection times are limited. Thermal decomposition of the matrix is more likely, which can lead to the formation of interfering compounds and reduce the sensitivity of the analysis.
Incomplete extraction: Some analytes may not be completely extracted due to low thermal stability or short extraction times, leading to lower recoveries and reduced sensitivity. Reproducibility issues: Exposure to the desorb gas may vary based on the tube loading, and the consistency of sample particle size and shape. Sample handling concerns: May be difficult to load the sample into ¼" OD glass tubes, requiring further grinding/sample preparation which may cause loss of some compounds. Flash Back Concerns: May cause contamination if the concentration of volatiles are too high, causing significant gas expansion that can push the sample “backwards” into the carrier gas delivery lines. |
| Extraction Time | 2-20 min | 2-20 min | 1-5 min |
Flash-VASE: A Safer and Better Way to do Thermal Extraction
Many systems attempt to perform thermal extraction by placing a sample into a tube and then directly thermally desorbing it into a GC. However, there are several draw-backs associated with this approach:
Samples may not transfer quickly from the sample to a GC column since chemicals of interest will not release very fast from many matrices, causing poor peak shape unless a secondary trapping or focusing system is used- Therefore, direct desorption methods often have to heat samples hotter to reduce band broadening, but higher temperatures will increase thermal degradation of the target compounds and the matrix
- Liberated compounds must remain in contact with the matrix longer during a pre-heating step, rather than allowing their removal once they become mobile
- Chemicals must diffuse out of the matrix at positive GC carrier gas pressures which slows down outgassing rates relative to a vacuum thermal extraction approach
Samples with a high volatiles content can backflash into the GC carrier gas delivery lines, permanently contaminating the lines until the entire injection system is removed and solvent rinsed.
Many matrices simply cannot be heated to GC injection temperatures, even momentarily, without changing them chemically, potentially creating artifact chemicals that were not in the original sample
There is no water/moisture management opportunities when directly desorbing a sample into a GCMS
Loading a sample into a 1/4” glass tube before direct desorption is more difficult than loading it into a vial, and some sample may drop into the desorber or injector, creating a background until removed
Flash-VASE solves all of these problems by performing an offline vacuum thermal extraction, followed by a moisture removal step if necessary while the sample/Pen assembly is still under vacuum in a closed system, simply by cooling the bottom of the sample vial to draw moisture back into the vial before removal and desorption of the Pen. This not only improves the performance of thermal extraction solutions, Flash-VASE may be the only way to perform thermal extraction on many sample matrices.
Flash-VASE Improves Performance over Off-Line Dynamic Thermal Extraction
Other thermal extraction systems use small chambers or micro chambers which attempt to thermally extract samples by heating them, flowing a gas over them, and delivering the desorb gas through an outlet port/fitting and into a classical sorbent tube. There are numerous problems associated with this approach as well:
- The cell or chamber can become contaminated when exposed to higher concentration samples
- Contamination of outlet tubing
- Many matrices simply cannot be heated to GC injection temperatures, even momentarily, without changing them chemically, potentially creating artifact chemicals that were not in the original sample
- Loss of low volatility compounds that adsorb to surfaces prior to reaching the TD tube
- Heating of the front of the sorbent bed can occur when trying to maintain a hot transfer system all the way to the collection sorbent. Hot gas introduced onto a sorbent will allow compounds to penetrate further into the sorbent, resulting in lower thermal desorption recoveries and greater potential for carryover
Channeling Effects are exhibited while flowing through a sorbent trap, causing reduced recovery, increased carryover, and increased thermal degradation by requiring higher desorption temperatures during analysis
Flash-VASE eliminates these concerns as well. The entire “cell” is the sample vial, which is used once and discarded, so no chance of carryover. There are no transfer lines and connective fittings in the flow path, as the opening of the Sorbent Pen is right at the top of the vial. There is no hot carrier gas to heat up the sorbent, so the penetration of compounds into the sorbent is far less, making their recovery during thermal desorption more complete and at lower desorption temperatures. The Flash-VASE closed system means that even very light compounds will be recovered, as long as they have more affinity for the sorbent in the Pen than they do for the heated sample matrix. Finally, the extraction occurs diffusively, eliminating channeling and all of the negative effects this has on recovery, carryover, and sampler lifetimes.
Compare All Sorbent Pen Extraction Techniques For Complete Coverage of VOC to SVOC Analysis Of Virtually Any Matrix
