Rd. Vaillancourt et Wm. Balch, Size distribution of marine submicron particles determined by flow field-flow fractionation, LIMN OCEAN, 45(2), 2000, pp. 485-492
Flow field-flow fractionation (flow FFF) with power field-strength programm
ing was used to size fractionate submicron particles (colloids) in coastal
seawater. All analyses used filtered seawater as carrier solution to preser
ve the native chemical environment of the colloids. Our fractograms show co
lloid size distributions with major peaks centered at 50 to 60 nm for sampl
es that were size fractionated immediately following the preconcentration s
tep. Preconcentrated samples that had aged for 2 to 5 d revealed the presen
ce of an additional larger sized particle (or aggregate) peak with indeterm
inate size. Errors in colloid sizing may result if the physical and chemica
l behaviors of the particle size standards are not mimicked by those of the
colloids during separation in the flow FFF channel. Particle detection usi
ng absorbance meters, such as the ultraviolet (UV) detector used here, grea
tly underestimates the contribution of smaller particles (ca. <100 nm) due
to the exceedingly small optical efficiency of particles within this size-r
efractive index domain.