A Pipet/Reagent Stand Entering an undergraduate organic chemistry laboratory and finding reagent bottles with their capsoff and pipets protruding from their mouths isan irritation. Finding pipets lying haphazardly about under a hood with no indication ss to which reagent bottle they belong is an annoyance. Scenes such as these in o w own labs prompted us to design and build a number of pipetheagent stands such as the one described below and shown in the figure. A 314 X 6 X 9-in. board was chosen as a base for our stand. On one end a rack measwing 3 X 5%in. high containing two holes [lO/lsin. diameter] in the top and two corresponding indentations in the base was constructed. A 6-in. test tube containing a circular piece [I2 mm diameter] of silicone rubber12 was placed in one of the holes. A thin 3/a X 1%-in. retainer wall surrounds the entire base. When in use, a reagent bottle is positioned on the end of the stand opposite the rack, and the pipet to he used with that reagent is placed in the adjacent test tube. We have found that the test tube is steady enough to hold a pipet with attached pipet filler. If an ear syringe3is used rather than apipet filler, it may be placed in the second hole. At the conclusion of each laboratory period, pipets, test tubes, and rubber discs are thoroughly washed and dried.
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The purpose of the silicone rubber discs is to minimize tip breakage by providing a cushion for our pipets. Its choice was based upon its inertness to a large nimher of solvents and reagents used in our laboratory. See Rochow, Eugene G., "Topics in Modern Chemistry-The Metalloids," D. C. Heathand Co., Boston, Mass., 1966, p: 68. Used glc septa serve t h ~ purpose s well. Hanson, Richard H., J. CHEM.EDUC.,54,434 (1977). James M. Garrett Stephen F. Austin State Univers~ty Nacogdocher TX 75962
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Journal of Chemical Education
