Filter-Pipets A modification of the filter-pipet designed by Rapoport and Hancock' was successfully used in the bottle-point2 method of determining adsorption isotherms for Cu2+on granular activated coke. The withdrawal of the supernatant solution free of coke particulates was achieved by means of the apparatus illustrated in the figure. This is a volumetric pipet connected with PVC tubing to a fritted-glass filter cup. The withdrawal of the sample is facilitated by the vacuum created by a pipet-filler attached to the upper end. The tiansfer of filtered supernatant solution may be accomplished in one minute. The fritted-glass filter cups are easily cleaned and may be constructed of fritted-glass sealing tubes in any desired porosity.
'
Rapoport, M., and Hancock, C. K., J. CHEM. EDUC., 98.39 (1962). 2Mattson, J. S., and Kennedy, F. W., J. Water Poll. Control Fed., 43, 2210 (1971). Department of Analytical Chemistry Catholic University Santiago, Chile
Guido A. Concha 1, I.,III.D*~
1". cYI
Volume 57, Number 9, September 1980 1 877
