Articles & Tech Notes

This month, we are discussing a complex problem that is becoming more and more prominent because of the chemistries specified and the ways of working that are being adopted by many users of evaporation equipment. We’re principally concerned with mixtures in which there is one volatile component and one high boiling point solvent. An example might be methanol /DMSO, or THF/pyridine. What's more, the two solvents don’t have to be within the same sample. A rack of tubes where each tube contains a different single solvent, will also exhibit the effect described below. Frequently a user who wishes to remove methanol/DMSO will not even mention the methanol when specifying the application, because methanol is “easy” and it’s the DMSO that is considered the challenge. However, this overlooks a rather important technical issue that we will deal with here.

Introduction: Penicillin, the first antibiotic, was discovered over 90 years ago and revolutionized medical potential. Before the advent of antibiotics, bacterial infections were a leading cause of death and the downfall of numerous surgical procedures. The capacity of antibiotics to enable patients to recover from severe infection and reduce the risk of infection of surgical wounds took the medical world by storm, leading to their routine use in both the management of disease and in prophylaxis. However, the resultant widespread overuse of antibiotics has led to many bacteria acquiring resistance to several of the most potent antibiotics available. This threatens the future of medical success as even the most efficacious antibiotics have been rendered inactive against life-threatening bacterial pathogens. Hundreds of thousands of lives are lost every year because of antibiotic-resistant infections.