Hydride generators are accessories used with atomic spectrometers for more sensitive analysis of certain elements. Particular techniques that benefit from hydride generation include atomic absorbance, atomic fluorescence (AFS), ICP and ICP-MS spectroscopy. Generators are specific to each analysis technique, but the underlying processes and results are similar. Yields improve for elements that form hydride compounds, enabling lower detection limits.

Hydride generation entails combining a sample with a reducing agent, such as sodium borohydride. Inside the generator, chemical reactions form hydrides—binary compounds of hydrogen and the element tested in the sample. Reactions with certain elements, mainly those that lie near the boundary between the metals and nonmetals on the periodic table (e.g., arsenic and germanium) produce volatile hydrides that are then drawn off as a gas from the sample. This concentrates the elements of interest into a gas stream, which is then introduced into the spectrometer for analysis.

Hydride generation combined with atomic spectroscopy provides a very specific and sensitive test for these elements. Demand for hydride generation comes primarily from environmental applications in public and private test labs, and industrial labs.

Arsenic analysis is most common due to environmental regulations’ requirements for low detection limits, but other hydride forming elements are also of interest. Another common application is mercury analysis, although the method differs somewhat. The hydride generation reaction produces elemental mercury, which is volatile enough to exist as a vapor and can be drawn off much like the hydride gases in more typical applications. Hydride generation enables mercury analysis in a wide variety of samples, from drinking water to fish.

The benefits of hydride generation include increased sensitivity and the ability to process difficult sample matrices, while a drawback is the additional cost of analysis. The elements that can be analyzed are also limited.

Complex hydride generators produce not just a hydride bearing gas stream but also a parallel sample stream containing the rest of the sample. This allows the sample’s complete elemental composition to be analyzed in a single run, rather than just the elements that form hydrides.

All of the major atomic spectroscopy vendors offer hydride generators, although some are third-party products. The top company in the market is PerkinElmer, offering its own products as well as the hydrideFAST 2 from Elemental Scientific, which produces only hydride generators. Large vendors like Agilent Technologies, Shimadzu and Thermo Fisher Scientific and are also significant with products designed specifically for their instruments. Teledyne Technologies competes in the market through both Leeman Labs and Cetac. Integrated systems are also on the market, such as the combined hydride generator and AFS from PS Analytical.

Hydride Generators at a Glance:

Leading Suppliers

• PerkinElmer

• Agilent Technologies

• Thermo Fisher Scientific

Largest Markets

• Environmental

• Academia

• Food

Instrument Cost

• $2,000–$12,000