The halogens are a chemical family of reactive nonmetallic elements. Chlorine is the most well-known from its presence in table salt, but the other halogens may also be familiar: fluorine, bromine and iodine. The last halogen, astatine, is radioactive with a short half-life, and thus does not exist in any appreciable quantities.

While small amounts of the halogens are present in humans, larger concentrations are toxic; thus, the halogens are a source of environmental concern. One particular variety of halogen compounds are called organic halides, in which one or more halogen atoms has been substituted for a hydrogen atom in an organic compound. While some of these compounds occur naturally, organic halides are also manufactured and used in a variety of industries. Many classes of organic halides are banned for industrial use, such as chlorofluorocarbons (CFCs) due to their destructive effect on the ozone layer, and dioxins and polychlorinated biphenyls (PCBs) due to their toxic effects on animals and humans. Others remain in use, but are generally subject to environmental regulations.

Various specific tests are used to regulate the halogens and organic halides. Among them are total halogen content (TX), total organic halides (TOX), adsorbable organic halides (AOX), purgeable organic halides (POX) and extractable organic halides (EOX). Most of the instruments that perform halogen analysis can perform several of the organic halogen tests. The most common method involves a pretreatment stage with activated carbon, followed by combustion. The combustion gases are scrubbed for interferences. The remaining halogen ions are measured by a coulometric titration. Alternative electrochemical technologies and even ion chromatography are used in some instruments. While water samples are the most common, these instruments can also be used to analyze soils, sludges and even gases for halogen content.

Applications for halogen analyzers are primarily focused on the environment. Environmental test labs are the largest source of demand, but most of the other significant uses of these instruments are also environmental in nature. Water utilities monitor drinking water, and government environmental labs monitor ground water and soil. Industrial users across a broad spectrum of industries from polymers to pharmaceuticals use these instruments to monitor the water they release. The pulp and paper industry is one of the most significant markets because the chlorine used to bleach paper can form organic halide compounds.

Mitsubishi Chemical Analytech leads in market share among a the short list of halogen analyzer vendors. The next largest vendors are Analytik Jena, Thermo Fisher Scientific and Yanaco. Other market participants include behr Labor-Technik, Elementar, PAC and Trace Elemental Instruments. Hach addresses this market through kits. Total 2012 revenues for halogen analysis amounted to about $10 million.

Halogen Analyzers at a Glance:

Leading Suppliers

• Mitsubishi Chemical Analytech

• Analytik Jena

• Thermo Fisher Scientific

Largest Markets

• Environmental

• Utilities

• Pulp and Paper

Instrument Cost

• $25,000–$50,000