Table of General Anesthetics |
History and Chemistry |
Usefulness of Ether |
Ether Unsuitable For Anesthetic |
New Generation of Anesthetics |
References |
GC-MS tutorial |
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The Problem: A historian from the National Museum of Civil War Medicine in Frederick, Maryland, discovers what he believes to be a mid-1800's medical kit on a Civil War battlefield near Knoxville in eastern Tennessee. Inside the kit is a small vial of liquid whose identifying label can no longer be read due to faded ink. Suspecting that the vial contains an anesthetic used in the Civil War, he sends the liquid to a laboratory to be examined. What is in the vial? Brief Background: Inhalation general anesthetics have evolved toward the point of ideality in the past 150 years. When chloroform's properties as an anesthetic were investigated by Sir James Young Simpson in 1847, ether had already been in use as an anesthetic for 15 years. Owing to the cost and amount needed to cause unconsciousness, Simpson introduced chloroform as an anesthetic upon recommendation from a chemist, David Waldie. The utility of ether as an anesthetic faded, and chloroform remained one of the standard anesthetics for many years until it was later discovered to be harmful to the human body. Due in large part to the safety factor, nitrous oxide, as well as halothane and some others, are now used to induce anesthesia in patients. See the Detailed Background page for more information on the history of the inhalation general anesthetics. The
Experiment: Because
the vial is suspected to contain an anesthetic, some of which contain
no or only a single hydrogen, proton NMR is of limited utility. Therefore,
it is recommended that a mass spectrum be obtained and compared to authentic
spectra. It is your job to help out the technician who has been charged
with identifying the compound found in the suspected Civil War medicine
kit. You should choose a mass spectrometry technique that will present
you with the data necessary to make legally binding conclusions regarding
the identity of the unknown. Once you have identified the compound,
be sure to submit your answer for the problem presented and also provide
logic for your results. |