Light scattering detectors dynamic

R. Peters, Y. Georgalis, W. Sanger, Accessing lysozyme nucleation with a novel dynamic light scattering detector. Acta Cryst. D 54(5), 873-877 (1998). doi 10.1107/S0907444998002455... 

The experimental techniques for the study of conformational branched properties in solution are the same as used for linear chains. These are, in particular, static and dynamic light scattering, small angle X-ray (SAXS) and small angle neutron (SANS) scattering methods, and common capillary viscometry. These methods are supported by osmotic pressure measurements and, nowadays extensively applied, size exclusion chromatography (SEC) in on-line combination with several detectors. These measurements result in a list of molecular parameters which are given in Table 1. 

For the mini-Dawn Tristar, dynamic light scattering signals are only collected from the 900 location, whereas for the Dawn Eros dynamic light scattering signals can be collected at any one of its 18 detector locations. 

In 1953, Stockmayer and Fixman [2] observed that the ratio of hydrodynamic (Stokes) radii Rh), given by the symbol h, could also be used as a measure of branching. Although they presented their relationship as a ratio of intrinsic viscosities [see Eq. (11)], the relatively recent introduction of on-line dynamic light scattering (DLS) detectors... 

In 1953, Stockmayer and Fixman observed that the ratio, h, of hydrodynamic or Stokes radii (/ h) of the branched and linear macromolecules could also be used as a measure of branching. The relatively recent introduction of online quasielastic light scattering (QELS, also known as dynamic light scattering and as photon correlation spectroscopy) detectors for SEC permits direct determination of h by... 

The average size and size distribution of miniemulsion droplets and polymer capsules were determined by dynamic light scattering using a Zeta Nanosizer (Malvern Instruments, UK), equipped with a detector to measure the intensity of the scattered light at 173 to the incident beam. 

The dynamic light-scattering measurements were performed on a CHROMATIX KMX-6 (LALLS) detector fitted on a classical GPC device equipped with two SHOWA DENKO mixed bed columns. In that device, the LALLS detector was followed by a refractive index detector (SHIM ADZU RID 6A). 

Table 1 Weight-average molecular weights obtained by GPC with PS calibration, light-scattering (static method) and GPC with light-scattering detector (dynamic method).

Other important detector types are fluorescence detector (FL), light scattering detector (LS), and the refractive index detector (RI). The FL detection offers the higher sensitivity and the lower detection limits. Nevertheless, these properties are frequently counteracted by the limited number of compounds with native FL therefore, additional derivatization reactions of analytes are usually needed, and the cost of acquisition and maintenance. In addition, when FL is used in HPLC systems, the linear dynamic range is often small for many analytes (even when the dynamic range is relatively large) and care should be taken... 

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