An Inexpensive Alternative to Pipet Flllers

In general experimental chermvtry courses, brcause of the rsquiremenrs of precise mra- suremrnts of liquid volumes, pipets are one of the must often used tnolr in the laboratory. Alrhaugh an ampledivrriity ofp~prtingdev~ccsarecommercially available(bulbs, rubber- pipet flllers, pi-pumps, ete.), their prices are generally high and mare than eight years of experience have shown us that their mean lifetime is not very long for fmst-level eourses. Recently, a note in this Journal'showed the use of plastic syringes as measuring pipets, which gave similar accuracy hut with advantages in rapidity of use and cost. Similarly, we are using in our experimental first-level chemistry courses dastic dis~osahle (reusable) syringesas a cheap alternative to commercial pipet fillers. The figure shows the device obtained by easy attachment of a plastic syringe and a pipet of the same volume using a 23 cm lone Teflon tubine of anorooriate diameter (usuallv it is necessarv to introduce a second sha; Teflon tube bred;ced diameter a t the svrin& edee to eet a correct adiust- , -~ ~ "~~ ~ ~~~ ~~~ ~ ~ ,~ ~~

ment, see the flcwre,. l lur system is cay to operate, qune economicnl, and allows us to toke out liquid samples from nsmw-necked flasks where synnpn, alone, cannot reach.

'Chiu. G. J. Chem. Educ. 1992. 69,666.

Agustin Galindo and Andres Ortega Universidad de Sevilla, Aptdo 553

41071 Sevilla, Spain

314 Journal of Chemical Education