Centrifugal vacuum concentrators like the Thermo Scientific Speedvac are commonly used in various analytical applications in the pharmaceutical, chemical, and biotechnical industries. The use of a SpeedVac has been very helpful in procedures such as DNA analysis. It helps to reduce the boiling temperature with a combination of vacuum-drying and centrifugation methods without destroying the integrity of dried samples.
As an industry-leader in providing new and recertified laboratory equipments, we produced this guide to help you assess the right SpeedVac equipment to meet your specific laboratory requirements. With these useful tips, you will gain an understanding of what factors you should consider when purchasing a SpeedVac. Find out how you can meet your application needs, know the importance of testing traps, be familiar with the different vacuum pump types, examine your lab space, and stay within your budget.
Identify your SpeedVac Application Requirements
What type of solvents do you analyze? Depending on the solvent type, the pump performance and evaporation efficiency of your experiment will vary. Use this information to figure out the type of vacuum pump and format size to use.
Used in preservation of samples containing water, aqueous solvents are best analyzed with a low vacuum pump. This is typically used in removing harmful ionic residue or contamination in water and in studies involving precipitation, acid-based substance and oxidation.
Primarily used as a raw material to manufacture chemicals and fuel to specialized vehicles, solvents such as Methanol, Ethanol, and Acetonitrile are classified as low boiling point organic solvents. An oil-free, low vacuum pump would be best suited for this type of solvent.
Aggressive, low boiling point volatile solvents such as chloroform, ethyl acetate, acetone, methylene, chloride, and hexane are used in a wide range of applications. Some usage examples include formulating pesticides as a cleansing agent, grain fumigant in fire extinguishers, and rubber production. Low vacuum oil-free diaphragm vacuum pumps are better suited and is the preferred choice for these type of solvents.
• Aggressive High Boiling Point
Samples involving solvents such as toluene, dimethyl formamide (DMF), and dimethyl sulfoxide (DMSO) are considered as high boiling point solvents. These type of solvents are commonly used in the production of acrylic fibers and plastics, pesticides, and in manufacturing adhesives. Deep end scroll vacuum pumps are best suited for analyzing these type of solvents. Although you can use any sample format, you may want to maximize the capacity of your speedvac. Due to the slow drying process, tubes or vials for small volume sampling are recommended to achieve higher throughput.
Strong Acids and Bases
It is difficult to separate acids from other solvents but with a SpeedVac it is possible to break TFA, HCl, Acetic Acid, Formic Acid, and other solvents with aggressive and, corrosive solvent properties. These type of solvents are commonly used in purifying organic compounds for recrystallization, in producing terephthalic acid (TPA), and raw material for polyethylene terephthalate (PET). With these type of solvents, microcentrifuge and microwell plates are the recommended sample format. Oil-free vacuum pumps are most commonly used with these solvents.
In pursuit of new discoveries, laboratory experts need an accurate sample format to use. The volume for your sample format depends on the capacity of your equipment and applications. Sample formats can range from 0.3 ml to 400 ml. Here are the most commonly used type of formats:
• Centrifuge Tubes
Great for storing and handling chemical substances, centrifuge tubes have a volume capacity range of 1.2 ml - 40 ml. Aqueous solvents are best tested in this type of sample format. Centrifuge tubes are often used for high-throughput-screening, DNA/RNA analysis, and polymer chain reactions.
Flasks are useful tool for containing liquid and performing various applications like mixing, heating, cooling, condensation, among others. This type of format comes in different size, materials, and uses. They are commonly used in larger applications such as isolation/synthesis of organic substance, toxicology, and forensics.
Often used to store medications in medical or molecular biological applications, vials has a volume capacity between 2 ml - 16 ml. They are used for analyzing smaller quantities of liquid such as blood or peptide test for diagnosing diabetes.
• Microwell or Microtiter Plates
Commonly used in small volume sampling applications like analytical research and clinical diagnostic for testing in laboratories, microwell plates typically have 6 - 1536 wells. These are very useful in analyses like enzyme-linked immunosorbent assay (ELISA) to detect HIV antibodies in a blood sample or hepatitis B markers in a serum.
The most difficult task during sample testing with a SpeedVac is the concentration and drying of samples in water under a vacuum. It is important to examine the drying rate since the heat temperatures vary with the sample that you are analyzing. The three heat chamber temperature are as follows:
- Low is at ambient temperature (chamber is off)
- Medium heats up the chamber at 43°C
- High heats up the chamber at 65°C
The Importance of SpeedVac Testing Traps
Testing traps serve the most important feature of a SpeedVac as they captures the solvent removed by concentration or the evaporation system. It prevents the solvent from reaching the vacuum pump which may cause errors in the analysis. By trapping moisture, vapors, and corrosive fumes, Cold Traps help protect the vacuum pump as they evaporate from the sample. Using the right temperature for your analysis can help protect your pump and help optimize the moisture trapping efficiency. Be sure to select the right temperature level for your cold trap:
- -50° C is used for aqueous solvents
- -85° C is used for aggressive organic solvents
- -105° is used to test non-aggressive organic solvents
Classify SpeedVac Vacuum Pump Types
It is paramount to be cautious with your samples while using a vacuum pump since there are potentially hazardous materials that might be included, even when using filters. There are a number of vacuum pump options offering a variety of capacities and levels. Most of the commonly used type are briefly discussed below:
When working with high boiling point aqueous samples and solvents, a Rotary Vane vacuum pump is a good choice. This type is the most commonly used since it costs less and is relatively smaller than the other pumps. Rotary Vane pumps can reach deep ultimate vacuum levels and have a high displacement capacity, which is good for freeze drying applications.
However, solvents trapped in the RV vacuum pump can condense in the pump oil and may cause damage on the inside. Although it can be costly to replace the oil every 3,000 hours of use, it helps to prolong the life of your pump. This type of vacuum pump is often used in automobiles, carbonators for soft drink dispenser fountains or espresso machines, gas applications, and as secondary air injection for auto exhaust emission control, or in low-pressure chemical vapor deposition systems.
As the name implies, oil-free pumps eliminates the need for oil. In terms of cost, these pumps are more expensive than RV vacuum pump. But in the long run, they are more cost-effective since there is no need for oil and other maintenance. Almost any type of sample can be analyzed with this type of pump, which is good if you do both evaporation and concentration. Oil-free pumps are frequently used for making artificial hearts and air pumps for filters in a fish tank.
Combination/Hybrid Vacuum Pumps
Hybrid pumps are basically RV pumps and Oil-free pumps put together. Oil can last up to 10 times longer with the hybrid pump since the oil-free pump reduces or eliminates the vapors condensing in the oil under negative pressure. While the cost that you have to incur may be higher when purchasing this type of vacuum pump, the operation costs are lower because less oil will be needed for maintenance.
Similar to the RV Vacuum Pump, hybrid pumps can reach deep ultimate vacuum levels and have high displacement capacities. But unlike the RV pump, these pumps are better at handling acids and solvents since the oil-free pump is incorporated into the system. This type of pump is often used in the paper processing industry, for creating suction cups and grippers, and in machinery for wood or glass.
Commonly used in air conditioner compressors and superchargers for automobile applications, Scroll Vacuum Pumps are recommended for aqueous and solvent samples. The cost of acquiring this type of pump can be high but the operation costs are much lower. This type of pump can reach deeper ultimate vacuum levels and have higher displacement capacities.
Lab Space Placement for your SpeedVac
Do you have a designated area for your SpeedVac? The placement of your vacuum concentrator SpeedVac in your lab space plays a role in deciding which model to purchase. The size of the equipment depends on the volume of analysis that you are conducting. When processing large batches of DNA/RNA samples, you will need high-capacity vacuum concentrators while for small-volume sampling you can opt for a compact unit.
Examining your Budget for SpeedVac
When working with a limited budget, the best approach for choosing a vacuum concentrator would be to rely on trusted distributors to provide high-quality recertified SpeedVacs. Research is key when exploring alternative options for your SpeedVac purchase. Although there may be a lot of models available, you should only opt for durable products that are tested to meet the strictest of industry standards of newly built equipment. It is wise to choose a reliable seller who has been in the industry for years.
To get the best out of your SpeedVac purchase, simply follow the tips above. Hopefully, this guide has provided insights to expand your familiarity with the SpeedVac and be able to choose the right one on your next purchase.