When to Combine Rotary and Blowdown Evaporation

The most popular type of evaporator found in analytical laboratories is the rotary evaporator. These units evaporate one sample at a time through the application of centrifugal force with vacuum and heat. There is a wide variety in the available sizes of rotary evaporators which allows for this concentration approach to be applied to a wide range of sample sizes, depending on the model and glassware utilized.

One reason why these units are so common is because evaporation is a frequently used process for sample concentration, and the ability to concentrate a sample, which would be difficult and time consuming to complete without equipment, provides a lot of utility to the lab technician.

Organomation is the preeminent manufacturer of multi-sample blowdown evaporators. Blow down evaporators apply a gentle stream of nitrogen air and heat to quickly evaporate excess solvent from several <50 mL samples at a time. In comparison, while rotary evaporators excel at concentrating one, larger sample at a time, nitrogen evaporators are used to concentrate samples held within test tubes for the purpose of lowering the volume further, such as to transfer into a 2 mL autosampler vial.

As these evaporator types excel in different areas, there are also numerous examples of these approaches being used in tandem. The 600 series EPA methods refer to a set of analytical methods published by the United States Environmental Protection Agency (EPA) and focus on the analysis of various environmental pollutants. These methods are used by laboratories to determine the concentration of contaminants in various matrices, such as water, soil, and air. We should note that our website hosts an extensive list of the standardized methods published by various regulatory bodies featuring Organomation sample evaporators.

Several of these 600 series methods have a section dedicated to Extraction and Concentration which states how extracts may be concentrated using rotary evaporation and then microconcentration is performed by nitrogen evaporation. While the to-be concentrated sample may be held in a 100 or 500 mL flask to start, through the application of first rotary and then nitrogen blow down, the sample is concentrated to final volume ahead of analysis such as gas chromatography, as is the case in EPA Method 1698: Steroids and Hormones in Water, Soil, Sediment, and Biosolids by HRGC/HRMS.

Organomation takes pride in being specifically listed as the nitrogen evaporation apparatus within a lengthy list of EPA methodologies. If you would like to discuss your specific sample preparation needs and determine which evaporator may be best for your lab, contact our team at 978-838-7300 or sales@organomation.com.