Figure 2. The product of tellurite reduction by catalase is elemental tellurium.

Absorption spectra of products formed upon the reduction of K₂TeO₃ in vitro by (A) 2-mercaptoethanol, (B) a crude extract prepared from S. epidermidis CH cells prior to chromatographic enrichment, and (C) purified bovine liver catalase, were resolved by Induced Coupled Plasma-Optical Emission spectroscopy [30].

All products show an absorption maximum at 214.281 nm, the peak wavelength of the Te° standard (triangle in panel A).

We note that the scale used to measure absorbance in the crude extract differs by a factor of ten from those used to measure absorbance in chemically prepared tellurium (A) and in the product of tellurite reduction by bovine liver catalase (C).

This is because the crude extract includes a plethora of components with absorption maxima at or near this wavelength.