Chemical and Engineering News Spotlights Purdue Mass Spec Research

Diagram of Leaf Spray Analysis technique
New technique utilizes copper clips attached to the plant tissue, application of a 4.5 kV jolt to it, and aiming of the tissue's spray of chemicals at the inlet valve of a mass spectrometer.
Under their "Latest News" banner, Chemical and Engineering News showcased the mass spectrometry work being done by Weldon School's Zheng Ouyang in conjunction with Graham Cooks and other colleagues.

The article, which is based on a publication to appear in the journal Analytical Chemistry, showcases the extrapolation of their paper spray technique of biological samples to evaluation of plant samples.

Both the paper and plant techniques rely on applying an electrical potential across a wet surface to produce a spray of ionized chemicals within tiny liquid droplets. In the plant technique, the scientists attach copper clips to the plant tissue, apply a 4.5 kV jolt to it, and aim the tissue's spray of chemicals at the inlet valve of a mass spectrometer. The method is non-invasive.

So far, the researchers have used the technique to analyze leaves, roots, seeds, and fruits from several types of plants, including green onions, peanuts, and cranberries. The method even worked on living potato and tomato plants.

With the technique, Ouyang and his team could measure alkaloids, sugars, lipids, amino acids, and other compounds in the plant tissues. Sample preparation takes seconds, which could allow researchers to routinely measure rapid chemical changes within plants, such as responses to stress. Traditionally, such studies have involved time-consuming sample preparation including chromatography, Ouyang says. "We want to make it really simple."