Chemistry researchers receive patent for new scientific measurement instrument

May 10, 2011

Two Baylor University chemistry professors have invented a new polarimeter, a basic scientific instrument used to measure and interpret the polarization of transverse waves, such as light waves, that could prove useful in determining the purity of pharmaceuticals. Baylor has now patented the device.

Certain compounds differ only in the way that they interact with polarized light. Plane polarized light is light whose electric vector moves back and forth in a plane. When plane passes through an optically active medium, the plane of polarization is rotated. The device that measures this rotation is called a polarimeter. To measure the rotation with a conventional polarimeter, a polarizing prism must be rotated and this requires some mechanical parts. Dr. Kenneth Busch, emeritus professor of chemistry at Baylor, and Dr. Dennis Rabbe, chemistry laboratory coordinator at Baylor, have developed a polarimeter that differs from others in that it has no moving parts, which eliminates problems associated with wear and tear and possible inaccurate readings.

"Our device uses two prisms whose planes of polarization are fixed at a certain angle with respect to one another," Busch said. "When these prisms are placed in the beam of a solid-state array detector , any rotation caused by an optically active compound rotates the plane of polarization. This rotation reduces the amount of light that reaches the detector of the spectrometer. Because we are using a spectrometer, the device monitors the rotation over a range of different wavelengths."

Busch said that by having a range of wavelengths with different rotations, researchers can use multivariate statistics to correlate the spectrometer signal with the optical activity of the sample.

Busch said one application that Baylor's polarimeter could prove useful is in pharmaceuticals. Most pharmaceuticals are optically active compounds composed of enantiomeric pairs. In some cases, one member of an enantiomeric pair is the active ingredient of the drug, while the other may be either inactive or toxic, which makes enantiomeric purity an important factor with drug formulations. Polarimeters are used to determine enantiomeric purity.

Explore further: Beer quality is no froth and bubble

add to favorites email to friend print save as pdf

Related Stories

Rotating light provides indirect look into the nucleus

Nov 30, 2010

Nuclear magnetic resonance (NMR) is one of the best tools for gaining insight into the structure and dynamics of molecules because nuclei in atoms within molecules will behave differently in a variety of chemical environments. ...

Quantum electronics: Two photons and chips

Jan 20, 2006

Scientists at Toshiba Research Europe Limited (Cambridge, UK) believe they are on to a way of producing entangled twins of photons using a simple semiconductor electronic device. Such a chip-based source of entangled photons ...

Light Scattering Method Reveals Details under Skin

Apr 12, 2005

A new optical method that can image subsurface structures under skin has been demonstrated by scientists at the National Institute of Standards and Technology (NIST) and the Johns Hopkins University Applied Physics Laboratory. The met ...

Physicists rotate beams of light

Apr 05, 2011

Controlling the rotation of light – this amazing feat was accomplished at the Vienna University of Technology (TU Vienna), by means of a ultra thin semiconductor. This can be used to create a transistor ...

Student Develops First Polarized LED

Mar 03, 2008

In recent years, light emitting diodes (LEDs) have begun to change the way we see the world. Now, a Rensselaer Polytechnic Institute student has developed a new type of LED that could allow for their widespread ...

Recommended for you

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.