Measurements of light scattering from flowing heterogeneous solutions conta
ining coexisting populations of colloids and polymers are presented. By app
ropriate recognition of scattering peaks produced by individual colloid par
ticles and recovery of the baseline scattering due to the polymer populatio
n, the colloid particle number density can be monitored in real time while
the polymer population is characterized absolutely according to weight-aver
age molecular weight M-w and z-average mean square radius of gyration < S-2
>(z). Either or both populations may also be evolving in time, so that the
technique is termed "heterogeneous time dependent static light scattering"
(HTDSLS). The essential notions of the technique are presented, and then th
e feasibility of the simultaneous measurements is first demonstrated by an
equilibrium characterization of poly(vinylpyrrolidone) (PVP) "contaminated"
by known concentrations of 2 mu m latex spheres. The time dependent capabi
lities are then demonstrated by monitoring the growth of Escherichia coli b
acteria in a solution containing PVP. It is expected that HTDSLS will find
many applications, such as in biotechnology reactors, biomedical assays, an
d polymer reactors where gels or crystallites are produced in addition to p
olymer chains.