Stanford researchers find a quicker, cheaper way to sort isotopes BY EMMANUEL ROMERO L.A. Cicero Professor Richard Zare in his lab. Whether it's the summer grass that tickles your feet or the red Bordeaux smacking on your palate, nearly every part of the world around you carries special chemical markers. These markers, called isotopes, can tell scientists where the molecules that compose a substance are from, where they traveled and what happened to them along the way. But doing these analyses has been complex and costly. Now, Stanford chemists have developed a new method to make isotopic analysis easier and less expensive.

 "It's all done with smoke and mirrors," said chemist Richard Zare, offering a very literal description of the new method. The device he and his collaborators have created burns chemical samples into a gas, which then flows through a laser beam that is bouncing back and forth off a set of mirrors inside a special container.

 Zare's co-authors on the paper include Stanford chemistry graduate student Douglas Kuramoto and Christa Haase, an undergraduate in chemistry at ETH, the Swiss Federal Institute of Technology in Zurich, Switzerland, who worked in Zare's lab last summer. A grant from Picarro Inc., a private gas analyzer manufacturer that Zare serves as a technical advisor and of which he is a founding member, supported the development of the current prototype. Other co-authors of the paper are Sze Tan, Eric Crosson and Nabil Saad, researchers at Picarro Inc. Emmanuel Romero is a science-writing intern at the Stanford News Service.