ATOM’s Excimer lamp emission has significantly higher spectral purity than other commercially available UV lamps such as Zinc and Xenon lamps.
The above graph reflects principle spectroscopic emission differences between a zinc lamp (blue trace) and ATOM’s Excimer UV lamp (red trace) across the UV and visible wavelength region. The 214nm zinc emission line traditionally used in UV Fluorescence analysis represents less than 20% of its entire emission spectrum. By comparison, the quasi-monochromatic emission of ATOM’s Excimer UV lamp represents about 90% of its total emission spectrum. The 222nm peak emission wavelength of ATOM’s Excimer UV lamp has been shown to be ideally suited and superior for the detection of total sulfur.
The ATOM Excimer technology is much less sensitive to interference from molecular-bound nitrogen, which can significantly affect the accuracy of sulfur measurement depending on composition of the analyzed samples.
The above 3 samples demonstrate the superior Nitrogen Rejection obtained with ATOM’s Excimer technology. The certified sulfur sample contains 1.453 ppm/wt sulfur as Dibutylsulfide whereas the nitrogen sample contains 8850 ppm/wt nitrogen as Pyridine. The Blank sample, as well as the balance of the two other samples, was HPLC-grade iso-octane. All samples were run in triplicate and the average of each sample was used to calculate nitrogen rejection according to the formula:
The molecular-bound nitrogen in the pyridine sample is nearly 0.9% by weight, but its response is less than half of the 1.453 ppm/wt. sulfur sample, resulting in a nitrogen rejection ratio greater than 5,000:1. Also note, that the Blank sample has almost no detectable response. This unsurpassed nitrogen rejection is highly beneficial in reducing measurement error when analyzing high nitrogen content samples for sulfur content.
The above graph shows achievable emission stability of ATOM’s Excimer UVF lamp over a period of 5,000 hours (about 7 months). After 7 months of operation, the lamp has only lost about 7% of intensity. Lamp lifetime far exceeds that obtained with other commercially available UF lamps.