State-of-the Art Comparability
of Corrected Emission
Spectra.1. Spectral Correction with Physical Transfer Standards and
Spectral Fluorescence Standards by Expert Laboratories
- Publication date
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Abstract
The development of fluorescence applications in the life
and material
sciences has proceeded largely without sufficient concern for the
measurement uncertainties related to the characterization of fluorescence
instruments. In this first part of a two-part series on the state-of-the-art
comparability of corrected emission spectra, four National Metrology
Institutes active in high-precision steady-state fluorometry performed
a first comparison of fluorescence measurement capabilities by evaluating
physical transfer standard (PTS)-based and reference material (RM)-based
calibration methods. To identify achievable comparability and sources
of error in instrument calibration, the emission spectra of three
test dyes in the wavelength region from 300 to 770 nm were corrected
and compared using both calibration methods. The results, obtained
for typical spectrofluorometric (0°/90° transmitting) and
colorimetric (45°/0° front-face) measurement geometries,
demonstrated a comparability of corrected emission spectra within
a relative standard uncertainty of 4.2% for PTS- and 2.4% for RM-based
spectral correction when measurements and calibrations were performed
under identical conditions. Moreover, the emission spectra of RMs
F001 to F005, certified by BAM, Federal Institute for Materials Research
and Testing, were confirmed. These RMs were subsequently used for
the assessment of the comparability of RM-based corrected emission
spectra of field laboratories using common commercial spectrofluorometers
and routine measurement conditions in part 2 of this series (subsequent
paper in this issue)