Researchers detect palladium

A team of chemists at the University of Pittsburgh has discovered an effective and cost-efficient method of detecting palladium and platinum deposits in a product, such as medicine.

This new technique uses a highly receptive fluorescent sensor to expose palladium and platinum vestiges in less than 60 minutes.

The research was conducted by chemistry professor Kazunori Koide, post-doctoral fellow Fengling Song, and chemistry graduate student Amanda Garner at the University of Pittsburgh.
Koide specializes in the organic synthesis of natural products, researching new synthetic methods,  diversity-oriented synthesis, and organic fluorescent sensors, as stated on his faculty web page.

The find was officially published online in the Journal of American Chemical Studies on Sept. 21.

Similar in chemical properties, palladium and platinum cater to a variety of uses, including the processing of pharmaceuticals, automobiles, and jewelry. They are also employed in the configuration of electrical devices such as spark plugs.

While usage of palladium and platinum is sought after, the extent of their presence is difficult to observe. Koide’s research focused on overcoming this setback.

As mentioned by the inventors in their published study titled “A Highly Sensitive Fluorescent Sensor For Palladium Based On the Allylic Oxidative Insertion Mechanism,” the fluorescent sensor method depends on a transparent “fluorescein-based” solution.

When this solution is brought to interact with even subtle quantities of palladium and/or platinum under ultraviolet (UV) rays, traces of palladium and platinum become visible to the naked eye.

In the publication, the team explains the many advantages of their multifaceted undertaking. In particular, they emphasize its great value to the pharmaceutical industry. In this industry, reactions that involve palladium as a catalyst often yield products that are contaminated with palladium. Such products are a hazard to people’s health.

Garner said, “Most pharmaceutical corporations use a significant amount of palladium to make drugs. Certain amounts of palladium are never removed — simply because they have not been detected. Thus, remnants of toxic substance find their way into the final product — i.e., the medicine.”

To test their method of improving the visibility of palladium, the investigating team brought samples of rock and dirt (which are thought to contain palladium and platinum deposits) into contact with the team’s “palladium sensor solution.”

The results were positive, meaning that researchers detected palladium deposits.

Furthermore, although each sample was under observation for about one hour, traces of palladium began to appear within the initial 10 minutes.

Garner said that the process is efficient and relatively simple.

“Our detection method does not rely on any expensive or elaborate equipment, which usually takes from days to weeks to detect traces. It is a simple, one-hour process, and is therefore more reliable and less time-consuming,” said Garner.

Due to its economical and convenient nature, this method is applicable to almost any kind of manufacturing that involves palladium or platinum.

“Our method can be used on the mining site,” Koide stated in a University of Pittsburgh press release. “And you don’t need a doctorate in chemistry — anyone can do this.”

In their publication, the chemists suggest that while it is advisable to use a UV lamp when trying to find palladium at a mining site, in most cases, the metal can also be detected without UV.

As stated by Garner, the team is in communication with Stillwater Mining Company, one of the world’s leading manufacturers of platinum group metals and the sole producer of palladium in the West.

The group has successfully conducted conclusive tests based on their palladium sensor for the multinational organization. The company intends to use this technology for detecting palladium deposits in mines.

This experiment has also successfully been carried out with a commercial aspirin tablet.

“The extent of this discovery came about as a surprise,” said Garner. “We had obviously anticipated the chemistry to work, but such remarkable visibility of the metals was beyond our expectations,” she said.

To learn more about Koide’s research, visit the Koide Group website at www.pitt.edu/~koide/group/, or refer to the study published online in the Journal of American Chemical Studies at http://pubs.acs.org/cgibin/sample.cgi/jacsat/asap/pdf/ja073910q.pdf.