Characterization of Standard Reference Material 2941, uranyl-ion-doped glass, spectral correction standard for fluorescence

Abstract

Standard Reference Material s (SRM s ) 2941 is a cuvette-shaped, uranyl-ion-doped glass, recommended for use for relative spectral correction of emission and day-to-day performance validation of fluorescence spectrometers. Properties of this standard that influence its effective use or contribute to the uncertainty in its certified emission spectrum have been explored here. These properties include its photostability, absorbance, dissolution rate in water, anisotropy, temperature coefficient of fluorescence intensity, and fluorescence lifetimes. The expanded uncertainties in the certified spectrum are about 4% around the peak maximum at 526 nm, using an excitation wavelength of 427 nm. The SRM also exhibits a strong resistance to photodegradation, with no measurable decrease in fluorescence intensity even after 8 h of laser irradiation. Published by Elsevier B.V.

Characterization of Standard Reference Material 2940, Mn-ion-doped glass, spectral correction standard for fluorescence

“…As the study proceeded, the actual surface area exposed to the water may have decreased with time as the surface roughness diminished due to dissolution of the high points. Accordingly, the final rate of dissolution, 0.23 mg/cm 2 /min is given here, which is equal to that of SRM 2941, observed previously [8]. This is equal to a log dissolution rate of À6.6 mg/cm 2 /min.…”

“…Many of the fluorescence properties of SRM 2940 have been characterized here to better understand the uncertainties and limitations related to its use as a standard. A similar characterization of SRM 2941 has been reported previously [8]. SRM 2940 is a ready-to-use, cuvetteshaped, Mn-ion-doped, solid glass standard whose certified values can be used to correct fluorescence emission spectra for distortions in the measured spectral shape, i.e., relative intensity correction, due to the changing responsivity with wavelength of the detection system of a steady-state fluorescence spectrometer.…”

“…A more detailed experimental description of many of these procedures has already been reported [8]. All uncertainties given here are expanded using k ¼ 2, i.e., 2s uncertainties, unless specified otherwise.…”

“…These measurements were taken at a fixed emission wavelength of 620 nm, corresponding to the peak maximum for SRM 2940. F and G values [25] were determined as described previously [7,8].…”

“…Many of the radiometric characteristics of glasses can influence their effectiveness as standards, including absorbance, fluorescence anisotropy, temperature dependence of fluorescence intensity, fluorescence lifetime and photostability [8]. All of these characteristics could cause observed fluorescence intensities and spectra to change with time or between instruments, which is not desirable for a standard.…”