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We have developed an analysis kit and associated methods for measuring selenium in a wide variety of sample matrices and at a variety of concentrations, down to single-digit parts-per-billion. Our selenium analysis kit (OV-PP-B005) provides the platform upon which all of our methods are based. Pre-treatment kits are available for coal-mine runoff, refinery waste water, and coal-fired power plant flue-gas desulfurization water.

Our selenium test is highly selective for the selenate (+6) oxidation state of selenium. With a simple oxidation process, the user can convert all selenium in a sample to the fully-oxidized, selenate state to determine the total selenium content. This selectivity enables selenium speciation, if desired, by performing two measurements, one oxidized and one not. The difference between the reported values is the selenite (+4) concentration.

The pre-treatment kits are designed to reduce interferences to enable ppb-level selenium measurements. The primary interferent is sulfate, which is frequently present at hundreds to thousands of parts per million. A simple solid-phase extraction column selectively reduces sulfate to the single-digit ppm range, where the selenium signal is then readily obtained. In addition, we offer two measurement ranges: 100-ppb and 1000-ppb. The higher range method has a detection limit of 50-ppb, while the low-range method can determine selenium concentrations to 5-ppb. Lower detection limits are possible by adjusting sample volume; contact OndaVia for additional information.