 | ||
 |
 |
Features Main
Periodic Table of Elements
About Team C004970
|
 |
A Trip to the Washington State Patrol Crime Lab
A Fourier Transform Infrared Spectrophotometer.
The computer that reads data from the FTIR
Gasoline vials, used as a baseline to detect and confirm traces of evaporated gasoline in arson cases.
A robotic arm used to take care of the mundane task of sample measurement.
The GC/MS (gas chromatograph/mass spectrometer) that analyzes the samples taken by the robotic arm.On July 26th, our team went on a trip to the Washington State Patrol Crime Lab. Our host, Mr. Erik Neilson, showed us around and let us take pictures of the tools and instruments that are used there. After a long drive, we finally arrived at the Lab in Marysville. The high security was rather intimidating, but with our white lab coats and yellow "visitor badges," we were ready for action! The first stop was the chemistry laboratory, where Mr. Neilson's work bench, along with those belonging to three of his colleague's, were found. Off to the side, Mr. Neilson showed us the gasoline standards for arson cases. These vials show gasoline, with the lightest ones being the least evaporated, and the darkest ones being almost totally evaporated.
In the main section of this laboratory, Mr. Neilson showed us the FTIR, which is an acronym for "Fourier Transform Infared Spectrophotometer." The FTIR measures the interaction of pure substances with infrared light, producing an infrared absorbance pattern that is like a molecular fingerprint, very useful for the identification of drugs and other organic substances. To the right of the instrument is the computer that both controls it and displays a graphical interpretation of the data that the FTIR puts out. By analyzing the infrared spectrum and comparing it to that produced by known standards, we could identify the compound being analyzed.
Next, Mr. Neilson took us into the Lab's equipment room, where, over the thirteen years he's worked there, the number of instruments has increased from a single device to enough that the counter is no longer visible. It's been said that the color of this fabled counter is peach, but no one knows for sure anymore...
Down the left of this text, you can see a robotic arm (4th picture down). This robot saves the analysts a lot of time. The sample tray can be filled and the robot programmed to pick up each sample vial and place it in a tower where a syringe removes a measured volume and injects it into the GC/MS, or gas chromatograph/mass spectrometer. These samples can be running overnight, unattended, allowing the scientists to do other tasks.
The GC/MS is another powerful anaytical tool (see 5th picture down). It is actually two instruments interfaced together. The gas chromatograph takes mixtures and separates the components, which are then analyzed sequentially by the mass spectrometer. The MS produces a molecular fragmentation pattern, another kind of molecular fingerprint that tells the analyst what the compound is.
As our tour wound to a close, we were able to see some of the substances the lab examines, and got our pictures taken in our nifty white lab coats. Our sincere thanks to Mr. Neilson for driving us ALL the way out to Marysville. (Don't worry, we treated him to a gourmet dinner afterwards!)
A fine white powder...
The three of us in our nifty white lab coats.
