Titanium dioxide was used as a model colloid to demonstrate the possibility of obtaining reliable values of the electrophoretic mobility in low-temperature ionic liquids. Mobilities as low as -0.98 +/- 0.16 x 10(-10) and -1.25 +/- 0.33 x 10(-10) m(2) V-1 s(-1) were found in dry and wet 1-butyl-3-methylimidazolium triflate, respectively. These values are lower by two orders of magnitude than typical mobilities in stable aqueous dispersions due to a high viscosity of the ionic liquids. (C) 2004 Elsevier Inc. All rights reserved.