An Inexpensive Syringe for Gas Chromatography Gas chromatographic analysis plays an integral role in our undergraduate organic chemistry laboratory. Because heginning students lack experience, they often have poor laboratory technique which results in a high mortality rate for expensive GC syringes. To overcome this problem and fight the ever-decreasing budget we have developed an inexpensive GC syringe. The body of the syringe is made from a disposable plastic insulin syringe (1 ec X 100units) that originally had a in. x 27 gauge needle. The needle is replaced by a 2-in. hypodermic or chromatographic needle purchased from American Scientific Company (Catalog No. S9670-3, Mfg. #90053,21 gauge; Catalog No. 9675-20, Mfg. #90027,27 gauge). A short piece of Tygon tubing (3116 in. i.d.) serves t o form a gas tight seal hetween the needle and syringe body. In practice the students draw 10 units of air into the syringe then 1unit or less of sample. The sample itself is always contained in the 2-in. needle. After use the syringe and needle are rinsed with acetone usine a standard svrinee cleaner (filter On oc&sions w h e n t h e k n e~ e oluneer flask, one-hole rubber StODDeI with elass t"be &d ruhher tuhine to hold svrinee). . . ~ . St~rksa very sl~ghtlubrirat& with &con stopcock grease s h e s the problem. We have uspd thii s y r i n g ~for a year in our ~ for cxpe~~sivr ( X syrinjim. lahoratorws and have found it to be a practical, i n ~ x p t n wsuhirirure
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Walter 6. Avlla, Mark A. Hamilton, a n d Eric A. Holwitt United States Air Force AcademyIDFC USAF Acadwny. CO 80840
Volume 61
Number 12
December 1984
1109
