Jun Zhao of Metrohm Spectro Wins Williams-Wright Award

This year the Coblentz Society celebrated the 47th anniversary of the Williams-Wright Award. The award is presented annually at Pittcon to an industrial spectroscopist who has made significant contributions to the field of vibrational spectroscopy while working in industry. The Award is named after Norman E. Wright of the Dow Chemical Company and Van Zandt Williams of American Cyanamid. Both Williams and Wright contributed greatly to the formation and application of industrial infrared spectroscopy over their careers. This year’s Williams-Wright Awardee is Jun Zhao, director of Engineering at Metrohm Spectro, Inc. The theme of this year’s session was the development and applications of Raman spectroscopy.

Zhao started off the session by presenting a talk titled “My Joyride on the Raman Spectroscopy Renaissance Express.” The renaissance of Raman spectroscopy began in the 1990s and shows no sign of diminishing, fueled in large part by new applications, innovative methods, and instrumentation advancements. Zhao likened the Raman industry to a great train carrying us into the future of analytical chemistry. He described his experiences and thoughts for the future of Raman. Zhao has devoted his career to the advancement of Raman spectroscopy instrumentation and methods with innovative work at Chromex, Bruker, and B&W Tek. He has over 90 patents, publications, and presentations, which have been cited more than 1,400 times.

Next, Kristen Frano from Metrohm Spectro presented, “Advances in Through-Barrier Raman Identification of Real-World Samples.” She discussed how Raman is valued as an identification technique by the pharmaceutical and safety and security sectors, but it faces limitations when test samples are inside visually opaque containers, hindering the use of Raman spectroscopy analysis. Frano described a “see-through” Raman technology developed to expand on the confocal design of most Raman systems and increase the relative intensity of the Raman signal from the sample inside of an opaque container, therefore allowing for better nondestructive identification of the sample through the container wall.

Richard McCreery of the University of Alberta presented “Raman Spectroscopy of Buried Interfaces in Molecular Electronic Devices.” McCreery explained the analysis of carbon-based molecular junctions consisting of 1-10 nm thick layers of aromatic molecules between conducting carbon surfaces used in audio processing circuits for many consumer electronics. Characterization these materials is challenging, since the required sensitivity for measurement is beyond the capabilities of commercial Raman spectrometers. McCreery explained the development of a custom Raman spectrograph by Zhao that has permitted measurements of carbon interfaces during fabrication and operation of molecular tunnel junctions.

The next talk, “Advancement in Practical Raman Instrumentation; the Early Years of Jun Zhao’s Career,” was presented by Mike Carrabba of Droplet Measurement Technologies. Carrabba explained that in the late 90’s, Raman was emerging as a technology that had potential both in process controls and general laboratory analysis. A major driving force was the advancement of compact diode laser sources that were both cost effective as well providing wavelengths that help reduce background fluorescence. Zhao developed two technologies that helped to overcome both sample and instrumental variabilities in his early career, namely, automatic fluorescence removal using shifted excitation Raman difference spectroscopy (SERDS), and also a method for achieving a standardized Raman spectrum that has both short and long-term precision and accuracy.

Tom Tague who is Applications Manager at Bruker Scientific presented a talk entitled “Overcoming Obstacles in the Raman Analysis of Art Objects.” Tague described Raman analysis as an important technique used in the conservation and authentication of art objects. Tague opined that Raman is very specific where each molecule has a “fingerprint” signature in the middle infrared region of the electromagnetic spectrum (4000-400 cm-1), where the Raman analysis result lies. Importantly, the Raman also yields results in the far infrared region of the spectrum (<600 cm-1). In this region inorganic based pigments manifest unique spectral responses, which is quite helpful for identifying the aspects of authentic art objects.