Rotary evaporators are one of the ways that fractional components can be distilled out of a solvent mixture, while minimizing heat input. In is simplest form, rotary evaporation is a boiling flask of solution is rotated on its side in a hot bath, while under vacuum, with the vapors being condensed and collected using a chilled heat exchanger. The rotation coats the inside of the boiling flask with a thin film, greatly enhancing film surface area and evaporation rates. Using vacuum instead of heat also allows fractionally distilling fragile substances sensitive to heat, such as carboxylic acids. By controlling the heat and vacuum level, individual fractions may be distilled off and collected at their different boiling points. There is more than one company manufacturing lab size rotary evaporators, and the cheapest is not inexpensive, sooo we'uns decided to attempt a comparison of available offerings, to share with ya'll. Not just what is available, and what does it cost, but what is the utility at the margin, aka bang for the buck, because they also range in price. One out of three success from our first round of importuning central suppliers for the loan of a test unit for impartial-pari-passu (IPP) (even, same/same, side by side) comparison with their competition, to share with our readership. Hee, hee, hee, snicker, snark, snort, I'm pleased to report that Heidolph is proud and confident enough of their Hei-VAP Precision ML G3, to supply it and a chiller for our trials and sooooo, we'uns have been having our way with her at the Pharm. She is a gaugus piece of precision equipment from zee fatherland, who gets extra points for being purdy to gaze longingly upon, but more importantly, she has been reliable and a joy to operate. A admirable quality that lingers in mah heart, after the honeymoon is over and the joy of her good looks wanes!! More fractional distillation experiments underway, but check out Jules report on ethanol removal using the Heidolph Hei-VAP Precision ML G3 at: /evaluation-of-heidolph-instruments-hei-vap-precision-ml-g3/ Thank you Jules from Specialized Formulation's for conducting the tests, as well as Rick from Botanical Analytics for lab space, and support. Thank you Heidolph for sharing the ML G3's charms with us'ns and readership! We admire manufacturers who are confident enough in their equipment to belly up to the bar for unbiased IPP comparison We also still have offers out to other manufacturers, and if any more decide to join us at the bar to strut their stuff, we will share that as well. Lu lu lu lu lu lu lu lu lu lu lu, let the fun begin!!