Ultraviolet-transparent cuvettes ideal for spectroscopy of optically opaque liquids
August 30, 2007, Redondo Beach, CA--ALine, Inc. has announced short-path-length, ultraviolet (UV)-transparent cuvettes for spectroscopy of optically opaque tannins and phenols. Measurement of wine color and tannins involves spectroscopic analysis in the UV and visible region. The test protocols are complex and are hampered by the need make multiple wavelength measurements. A typical spectrophotometer can only make one wavelength measurement at a time.
Also, the assessment of total phenols requires measurement of the sample at 280 nm, requiring the use of an expensive, difficult-to-clean and easily breakable 1-mm-path-length quartz cuvette. Even with a 1 mm pathlength, most red wines still require 5- to 10- fold dilution to keep the absorption at 280 nm near 2.0 OD, further complicating the test protocol.
In a new application note, ALine Inc. reports the performance of a new short-path
cuvette, the SpecVette with an Ocean Optics HR4000 spectrometer using a balanced deuterium-halogen light source to measure the absorbance of undiluted red wine samples from 250 to 650 nm.
The SpecVette slides into a 1 x 1 cm sample holder and the sample windows are filled with the liquid sample via standard pipettes. The SpecVette allows UV light to pass through it, allowing interference-free spectroscopy of the sample. Because the SpecVette cuvettes are disposable, cleaning and contamination of the sample are eliminated.
ALine introduced the application note at SPIE's Optics + Photonics exhibition in San Diego, CA, Aug. 28-30. The application note is available on ALine's website.
Valerie Coffey-Rosich | Contributing Editor
Valerie Coffey-Rosich is a freelance science and technology writer and editor and a contributing editor for Laser Focus World; she previously served as an Associate Technical Editor (2000-2003) and a Senior Technical Editor (2007-2008) for Laser Focus World.
Valerie holds a BS in physics from the University of Nevada, Reno, and an MA in astronomy from Boston University. She specializes in editing and writing about optics, photonics, astronomy, and physics in academic, reference, and business-to-business publications. In addition to Laser Focus World, her work has appeared online and in print for clients such as the American Institute of Physics, American Heritage Dictionary, BioPhotonics, Encyclopedia Britannica, EuroPhotonics, the Optical Society of America, Photonics Focus, Photonics Spectra, Sky & Telescope, and many others. She is based in Palm Springs, California.