Today we asked Dr.T of a National Research Organization, who is developing a technology to detoxify persistent organic pollutants (POPs) that cannot be decomposed by the natural purification process in soil, using microbial material resolution (bioremediation), about his opinions and requests for our products.
Dr. T, Senior Researcher at a National Research Organization
┃Dr. Honda's research content
My research theme is to understand and control the dynamics of persistent organic compounds such as pesticides in the environment, especially in soil. In particular, we are working on the development of bioremediation technologies for triazine compounds such as simazine, melamine, and POPs pesticides including hexachlorobenzene (HCB), hexachlorocyclohexane (HCHs), pentachlorophenol (PCP), dieldrin, and endosulfan, using degrading microorganisms -we have a lot of patented strains- and carbonized woody material. For the elucidation of the dynamics of POPs, it is essential to determine the chemical structure of trace amounts of degraded metabolites. Smart Evaporator is used to dry up the microbial degradation culture medium as the pretreatment for the analysis by single crystal X-ray structure analysis system or LC/MS system used in that process.
My current collaborator originally has known about Smart Evaporator, and we went to see the device together to BioChromato’s exhibition booth in JASIS (November 2020) held at Makuhari Messe. I fell in love at first sight with the device, which could easily concentrate a small amount of water from tea.
We use a Smart Evaporator in the process of separating and purifying sample solutions, concentrating samples with a large amount of solvent in screw tubes , and storing samples in vials. A variety of residual solvents such as CPME and dichloromethane are removed. A 50ml screw tube containing 5ml to 30ml of sample solution is operated for concentration at 40℃ setting. Since the complete removal of residual solvent is required in the experimental process, we use rotary evaporator, Smart Evaporator, and vacuum pump together.
In the future, we expect the improvement of the recovery rate in pretreatment work using Smart Evaporator. The recovery rate was 33% when the aqueous sample in a glass vial was dried and solidified, then dissolved again by adding 2.5 mL of acetonitrile and sonicating for 1 minute.
Since a large amount of salt from the culture medium was precipitated by the drying and solidification process, there was a concern that the salt and a small number of metabolites were adsorbed together on the glass wall.
We hope that tips on how to improve the recovery rate when re-dissolving aqueous samples using organic solvents after drying and solidifying will be shared as the know-how of Smart Evaporator users.
We are also attempting to analyze the single crystal X-ray structure of trace pesticide degradation metabolites using the crystalline sponge method. We aim to directly identify the chemical structures of trace unknown metabolites extracted from microbial culture media, without the need for exact mass analysis by mass spectrometer or structural estimation based on NMR spectra.
In the future, each of the dozens or hundreds of unknown peaks detected in the chromatogram will need to be fractionated by LC, concentrated, and dried. For example, if Smart Evaporator supplied by your company can dry and solidify samples using 12-, 24-, or 96-well glass plates, I think that the subsequent pickup of single crystals and handling of the crystal sponge method will be more efficient.
Thank you very much for taking the time for the interview, Dr. T. Even now I still remember vividly the very lively conversation we had, in front of the equipment which was evaporating a tea sample on it, at the JASIS exhibition. I felt that the activities of Dr. T, who is working on the purification of persistent organic pollutants that are harmful to human health and the environment through the development of bioremediation technology, will bring a more secure daily life for us. We also received a request to share the information on what other users are doing to improve the recovery rate in the pretreatment process of analysis using Smart Evaporator. We are reminded of that our new mission is to build a network of users in various research fields who have the know-how of Smart Evaporator. Thank you very much for your very valuable feedback. We will continue to do our best to meet your expectations.
■Interested in what Smart Evaporator is? You can learn from here!