Varian launches diode array detector for HPLC applications

Palo Alto, CA—Varian Inc. has introduced a new diode array detector (DAD) line for high-performance liquid chromatography (HPLC) applications in the biotechnology, pharmaceutical, environmental, food and beverage, and other industries.

By Control Engineering Staff May 4, 2004

Palo Alto, CA— Varian Inc. has introduced a new diode array detector (DAD) line for high-performance liquid chromatography (HPLC) applications in the biotechnology, pharmaceutical, environmental, food and beverage, and other industries. The company reports that its new ProStar 335 DAD line features the first and only true scale-up detector, capable of going from analytical applications at the earliest research stages to a fraction purification process in a production environment. By eliminating the need for separate analytical and preparative detectors, this single detector gives users added flexibility, convenience, and control.

When integrated into an HPLC system, which is an UV-Vis detector that measures the amount of light absorbed by compounds as they elute from an HPLC column to determine the quantity of each compound analyzed. For each compound, the detector produces a specific signal, or peak. In addition, DADs simultaneously monitor absorbance across a broad UV-Vis light spectrum using a digital array of photodiodes, instantly adding a further dimension of information and quality assurance to the analysis.

ProStar 335 DAD features two models: a single-array detector for analytical, including microbore, applications and a dual array detector for analytical to preparative applications. For users involved in analytical applications, the new single-array ProStar 335 DAD, with a 1024 diode array and programmable slits, provides outstanding sensitivity, spectral resolution, and extended wavelength range (190 nm to 950 nm) to produce superior results, especially important in areas such as drug discovery and pharmaceutical quality assurance.

As with other information-rich detectors used in chromatography, such as mass spectrometers, DADs also provide a more certain analysis by automatically reviewing multiple spectra across a single peak, and assuring the user that the peak is pure and not contaminated with additional com-pounds emerging from the HPLC column at exactly the same time. Varian’s new ProStar 335 DAD is even more information rich because it allows the user to confirm purity of both the largest and smallest peaks in a single analysis.

Unique focusing lenses in the flow cell dramatically reduce refractive index effects, providing extremely stable performance even during more demanding gradient HPLC separations. This baseline stability allows users to see detailed information with even trace amounts of analytes. Adding to quantitative accuracy, ProStar 335 features patent-pending seamless spectral coverage technology (SSCT), which means that the photodiode arrays in the ProStar 335 are coated with a unique material that filters out unwanted or stray light to eliminate interference.

Control Engineering Daily News Desk
Jim Montague, news editor
jmontague@reedbusiness.com