Multiple-scattering artifacts are a not uncommon difficulty in applications of quasielastic-light-scattering spectroscopy (QELSS). An earlier proposal [G. Phillies, J. Chem. Phys. 74,260 (1981)] for a two-beam, two-detector light-scattering spectrometer, which is only sensitive to singly scattered photons, is subject here to an experimental test. The device is found to work essentially as predicted. The diffusion coefficient of $0.091-\mu$m polystyrene spheres in water is concentration independent for solute volume fraction ≲0.01. Multiple scattering does not have a significant effect on the QELSS spectrum of bovine serum albumin at a protein concentration of 20 wt.%.

• Received 28 April 1981

DOI:https://doi.org/10.1103/PhysRevA.24.1939