the redispersed treated pulp water phase in units of mg l s is the solids content of redispersed treated pulp in units of g fiber g slurry u03c1 is the density of the pulp water slurry in units of g l typically 1000 g l for dilute solutions imidazoline concentrations were measured in water by using a dr 2010 portable datalogging spectrophotometer commercially available from hach company located in loveland colo the spectrophotometer method 401 for quaternary ammonium compounds was employed using suitable blanks and dilution imidazoline concentrations were measured on fiber using a liquid extraction procedure consisting of oven drying the pulp for 4 hours at 105 u00b0 c weighing out 5 g of pulp and placing it in 100 ml of anhydrous methanol in a 125 ml container the pulp methanol was then placed in a lab line model 3590 orbital shaker bath commercially available from lab line instruments melrose park ill which was operated at 300 rpm for 2 hours an aliquot of the liquid sample absorbance was then measured at 238 nm on a hewlett packard model 8453 uvnis spectrophotometer commercially available from hewlett packard company located in palo alto calif this value was used with a prepared calibration curve using the identical procedure with imidazoline spiked.