Krimer Nicolás I, Rodrigues Darío, Rodríguez Hernán B, Mirenda Martín
Gerencia Química, Centro Atómico Constituyentes, Comisión Nacional de Energía Atómica (CNEA-CONICET), Av. Gral. Paz 1499, B1650KNA San Martín, Buenos Aires, Argentina.
Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA, UNLP-CONICET), Facultad de Ciencias Exactas, Universidad Nacional de La Plata , Casilla de Correo 16, Sucursal 4, (1900) La Plata, Argentina.
Anal Chem. 2017 Jan 3;89(1):640-647. doi: 10.1021/acs.analchem.6b02819. Epub 2016 Dec 21.
A simplified methodology to acquire steady-state emission spectra and quantum yields of highly absorbing samples is presented. The experimental setup consists of a commercial spectrofluorometer adapted to transmission geometry, allowing the detection of the emitted light at 180° with respect to the excitation beam. The procedure includes two different mathematical approaches to describe and reproduce the distortions caused by reabsorption on emission spectra and quantum yields. Toluene solutions of 9,10-diphenylanthracence, DPA, with concentrations ranging between 1.12 × 10 and 1.30 × 10 M, were used to validate the proposed methodology. This dye has significant probability of reabsorption and re-emission in concentrated solutions without showing self-quenching or aggregation phenomena. The results indicate that the reabsorption corrections, applied on molecular emission spectra and quantum yields of the samples, accurately reproduce experimental data. A further discussion is performed concerning why the re-emitted radiation is not detected in the experiments, even at the highest DPA concentrations.
