Inexpensive Buret Tips and Sample Tubes

l l s n y undrryrmluatt chrmicrr). Inlwrstmes wntmur ro urr \I(*hr t\.pe l ~ ~ r e t . due tl) I~r lm l~muimon~ The 4iipc:liing rnrchnnt.~u in\olrrt rubhrr rulun:. n gla.5 brad or pinch r lamp.nnd n gin-i buret deliwry t i p TIM Ltt1 r i r t ,n w't, sl,mt $11 lid, i; fmyale, ;and thr c?pl l l ; l ry ~11ter1 IIPC(.OIPI I ~ I ked d w I U lmh u t clcaniny :after usr. Thew i.a i l m p wlution tr, th..* prohlem.

Disposable polypropylene pipet tips are inexpensive, durable, and function very well as buret tips. The tapered harrel is easily cut with scissors or a razor blade to enlarge the hole for the desired delivery rate. The top end can also be cut to fit the rubber tubing. If they do become plugged during use, their price makes them truly disposable. Many vendors sell these pipet tips in hulk for about 3 or 46 each. The Fisher Scientific Company sells the Eppendorf brand for $5511000.

A second use is for small sample containment. The tip is easily heat sealed by touching to a hot plate surface. A small cork (size 00) can be used tocap this sample tube. A mass spectrometer sample wassuccessfully mailed in an envelope eon- raining such a tuhe.

University of Wisconsin-Eau Claire Allen A. Denio Eau Claire, WI 54701

464 1 Journal of Chemical Education