Spectroscopy-01-01-2008

In part I of this series, columnist David Ball laid the groundwork for why the scientific understanding of nature in the late 19th century was found wanting: it could not explain a variety of phenomena that scientists were examining. (One of these phenomena was spectroscopy itself!) In this installment, he reviews the paradigm shifts in science that preceded the development of the currently accepted theories of the nature of matter. It all starts with the nature of light.

Featured products from the spectroscopy marketplace.

There are straightforward motivations for miniaturizing an optical spectrometer. If an instrument can be made smaller, it often will also consume less power, enabling it to be portable and eventually handheld, which allows the spectrometer to be taken to the sample. This article describes various miniaturization techniques and focuses on the mid-infrared; subsequent articles will examine near-infrared, UV?vis, and Raman spectrometers.

Inductively coupled plasma (ICP) spectroscopy is an important optical emission technique, with strong applications in environmental testing and related areas. The basic principle of ICP involves the introduction of a liquid sample into an argon plasma torch, which provides the excitation energy required to stimulate atomic emission in the sample. The geometry of the torch with respect to the optical components provides one source of control over the analysis. The axial mode, with the optics directed toward the plasma jet, provides better detection levels, although the radial (side-on) mode generally is less problematic.

In this month's installment, columnist Ken Busch addresses the molecular applications of inductively coupled plasma linked with mass spectrometry (ICP-MS), and how those applications have developed.

The authors use a novel MIR laser-induced breakdown spectroscopy (LIBS) probe, biochemicals, and inorganic alkali metal salts to produce emissions in the MIR region from atomic and oxygenated molecular breakdown species.