Spectroscopic Measurements of Temperature with Uranyl Compounds

Abstract

A new class of fluorescent probes for measuring temperature is described. The intensities of the strong fluorescence bands of uranyl acetate, uranyl nitrate hexahydrate, and uranyl orthophosphate were recorded when the uranyl compound was illuminated with an argon-ion laser operating at 488 nm. The intensity ratio of two fluorescence bands of uranyl acetate at room temperature were determined for five freshly prepared samples and shown to be independent of the intensity of the laser excitation and optical alignment. The intensities of the fluorescence bands lying between 500 and 570 nm were measured at various temperatures ranging from 77 to 295 K. The ratio of the intensities of two fluorescence bands was calculated and shown to vary linearly with temperature. A linear fit provided the slope. The largest positive slope of all the intensity ratios associated with uranyl acetate was 6.02 × 10−3 K−1, that associated with uranyl orthophosphate was 4.68 × 10−3 K−1, and that associated with uranyl nitrate hexahydrate was 1.81 × 10−3 K−1. The potential of uranyl compounds as a new group of temperature probes is discussed.

Light Emission Diode Water Thermometer: A Low-Cost and Noninvasive Strategy for Monitoring Temperature in Aqueous Solutions

“…Thus, during the last decade, considerable interest has been focused on the development of spectroscopic temperature sensors. [2][3][4][5][6] Two different types of spectroscopic measurem ents of temperature, those related to bulk properties and those concerning molecular attributes, can be mentioned. 4 In the rst case, it is well known that the emission of the infrared radiation of a given object is normally used as an indication of its temperature.…”

“…However, m olecular-based measurements have attracted the attention of researchers during the last years, as they allow the development of highly sensitive sensors and, in some cases, the resolution of spatial therm al gradients. 2,5 Th e tem p era tu re-indu ced ch anges in th e uo re scence 2,3,5,6 or in the absorbance 7 of different chemical systems have been proposed for m easuring the temperature of different types of systems. With these approaches a precision ranging between approximately 1 8C and 0.2 8C can be achieved.…”

Monitoring the Temperature of Dilute Aqueous Solutions Using Near-Infrared Water Absorption

“…The m ajor drawback of this approach is the dif culty of nding substances showing suitable temperature-dependent spectroscopic properties. The thermally induced changes in the intensity of uorescence of different compounds has been frequently proposed [2][3][4][5][6] as a thermometric property. Unlike uorescence, absorbance in the UV-Vis region has received much less attention due to the scarcity of compounds showing a suitable temperaturedependent absorption spectrum.…”

Atomic spectrometry update. Advances in atomic emission, absorption and fluorescence spectrometry and related techniques

“…Although not an application used specifically to detect atoms, Barabas et al 230 have proposed a new class of fluorescent probes for measuring temperature. The intensities of the strong fluorescence bands of uranyl acetate, uranyl nitrate hexahydrate, and uranyl orthophosphate were recorded when the uranyl compound was illuminated with an argon ion laser operating at 488 nm.…”