Under Pressure: How Pressure Can Speed Up the Extraction Process
📂Case Overview: Cornlumbo finds a solution to a client's dilemma by unconventional means. An explanation of the Pressurized Speed Extraction process is offered as a means of speeding up the client's process.
The detectives gather in the office to celebrate the success of Miss Mapple and Nancy Beef’s conference celebrating the achievements of women in science in New York. Cornlumbo’s half-built water-boiling device that he tried to construct when the kettle had broken is still sitting on the desk in the corner of the office. Miss Mapple is investigating the odd-looking contraption and wondering what was going through Cornlumbo’s head when he built it.
The makeshift kettle was constructed using a large heating flask sealed at the top, from which metallic pipes emerged and entered some bizarre accordion-style bellows. “What on earth is this thing, Cornlumbo? It looks half-kettle, half-accordion,” asks Miss Mapple. “Ah, well, I call it the ‘super pressure-reducing kettle v1’; the pipes and bellows are part of the pressure manipulation system,” says Cornlumbo. Miss Mapple looks even more confused than before, and the rest of the detectives become intrigued and gather around to hear Cornlumbo explain. “As you can see, I took a heating element from an old kettle and submerged it in the water. Then, I adapted a rubber bung so that the power cord of the heating element and the pipes could come out of the top while maintaining a sealed device,” explains Cornlumbo.
Eggcule Poirot interrupts as he can’t see why all the fuss with a sealed system and a rubber bung, “Surely, all you needed was the heating element and the heating flask; why not just plug it in and switch it off once the water had boiled? You can see when it is boiled through the glass,” says Eggcule Poirot. “You’re right, Eggcule, but that wouldn’t have benefited from my pressure manipulation system. You see, once you plug in the heating element, you pump the bellows, creating a vacuum that reduces the pressure and reduces the water's boiling point, speeding up the process. I was testing the bellows when you fixed the old kettle, so I never got around to finishing my invention. I had planned to attach my old harmonica to the bellows so you could play a merry tune while the water boiled,” says Cornlumbo.
The detectives faces show a mixture of bewilderment and awe. “Though this be madness, yet there is method in’t”, says Shallot Holmes quoting Hamlet. “It appears this contraption was not to be,” says Miss Mapple to the amusement of the detectives. Shallot Holmes then brings up the details of the latest case.
A client performs extraction using the classical Soxhlet method, but they are desperate for a quicker process as it is the bottleneck slowing down an otherwise fast and efficient procedure. “Do you have any other suggestions for how the client may perform their extractions?” asks Holmes.
Nancy Beef explains another method the client could use to extract compounds from various materials. She describes sonication extraction that uses high-frequency ultrasonic waves to agitate a sample immersed in a solvent. The ultrasonic energy causes the formation and collapse of small bubbles through cavitation. The agitation breaks cell walls and membranes, releasing the target compounds into the solvent. Shallot Holmes agrees that the method may be faster but also requires careful optimization of parameters, which would create more work for the client.
Eggcule Poirot suggests microwave extraction to speed up the process. The basic principle involves using microwave energy to heat solvents in contact with a material, facilitating the extraction of compounds. The microwaves cause the solvent molecules to vibrate rapidly, generating heat that breaks the bonds between the compounds and the material, partitioning analytes from the sample matrix into the solvent. Again, Shallot agrees that this would be quicker than the client's current method, but the high temperatures could lead to the degradation of the heat-sensitive compounds that the client works with.
Cornlumbo then makes a suggestion. “They need an accordion attached to their machine,” he says. The detectives are again baffled and look to Cornlumbo for an explanation. Cornlumbo explains his thinking and says that the limitation of the Soxhlet method is that it performs the extraction at atmospheric pressure. It is, therefore, limited by the boiling points of the solvent being used. “Therefore, if the client attached bellows to their system, like in my super pressure-reducing kettle, they could change the boiling point. The difference is that the client would want to increase the pressure in their system, unlike my kettle, which reduces pressure. By increasing the pressure in their system, they could use accelerated temperatures in their system which are even above the boiling point of the solvent. This way they can reach a higher extraction efficiency in a shorter time and the increased pressure also improves the penetration of solvent and sample, further increasing the efficiency,” explains Cornlumbo.
“You’re absolutely right, Cornlumbo, but I don’t think I’ll advise the client to attach an accordion to their device. A modern Pressurized Speed Extractor will be much better,” says Shallot Holmes. Holmes explains that modern PSE instruments have automated sealing, as opposed to a rubber bung with holes drilled into it, and they are easy to assemble quickly and have sophisticated valve systems, unlike Cornlumbo’s super-pressure-reducing kettle. Additionally, the client could use the same vessels to collect their extract as they already use for concentration in their other laboratory equipment, which makes a transfer redundant. “Yes, a modern PSE system will offer high sample throughput and repeatability and allow the client to use up to four different solvents per run - and run solvents sequentially, allowing huge optimization possibilities. Great work, Cornlumbo! It’s just as Einstein once said: If at first the idea is not absurd, then there is no hope for it,” says Holmes before heading off to advise the client. Feeling encouraged by Shallot's kind words, Cornlumbo went to look for his old harmonica to attach to his kettle.