Cromatografia

T-shirt Chromatography
A Chromatogram You Can Wear
Jeanne M. Buccigross 670 College of Mount St. Joseph, Cincinnati, OH 45233-1
Chromatography is a n important technique used by chemists to separate mixtures ofchemicals 1 , P a ~ e r c h r o 1. matography &felt tip pens and marker inks i s popular lab activity for v o u w children (2.3). Chalk chromatoma. .. phy of felt-tip markers uslnfimethanol a s the solvent also has h e w presented for older students (41.Wlth the advent of T-shirtpainting and the return of tie-dyed T-shirts, application of the principles of chromatography ( I )to T-shirts is a timely, entertaining and informative activity for young children, as well as a n entertaining activity for more advanced chemistry students. The requirements for acceptable T-shirtchromatograms a r e somewhat different from traditional chromatoerams. The finished T-shirt must stand u p to perspiration &d repeated l a u n d e r i n g without bleeding o r fading, a n d i t should look attractive. On the other hand, i t does not have to be stringently reproducible, nor does it have to provide quantitative separation. Method 1: Permanent Markers

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Materials
permanent felt tipmarkers (Sharpie, El Marko etc.) .T-shirt, prewashed methanol (wood alcohol) or ethanol 4-L beaker or other glass container w a t c h glass or plate to mver heaker Jo Sonja textile medium (recommended) safety glasses rubber gloves fume hood (last four steps)

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Two Methods for T-shirt Chromatograms This paper presents two methods for producing "stateof-the-art" T-shirt chromatograms. .The firstmethod utilizes permanent (nonwater soluble) markers. The results of this method are more satisfadarv than the second, but it requires methanol or ethanol as a solvent which will be a disadvantage in same settings. The second method employs water soluble markers, and thus water as a solvent, hut the separation is not as good, and it is more diff~cdt make these chromatograms pwmato nent. CautionMethod 1. usine nermanent markers.. reauires the use of .. . methanol or ethanol. Both are organic solvents and require safety procedures. Methanol a n d ethanol a r e toxic solvents, Inhalation ofthe vapors a n d skin contact must be avoided. These methods m u s t b e performed in a fume hood AU participants must wear rubber o r latex gloves a n d safety goggles.

Procedure Wash and dry yourT-shirt before beginning. This will remove any sizing or other conditioners that may interfere with the dye. A shirt made of 100%cottan is recommended for best results, although we have had success with some cotton and polyester blends as well. Lay the T-shirt flat on a table. Place a sheet of paper or plastic wrap inside the shirt, between the front and back. This will keep the ink from goingthrough to the back. Choose " Dens. Use ones which sav "nermanent." Sharnie vour . Dens work well. esneciallv black. red: blue and ~ ~ ~-- meen.$l ~ Marko pens also work well, especially orange, purple, green and yellow. Place small (about 114 in.) dots of color about one inch from the bottom of a child's shirt, or about 112 way up an adult's shirt

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Use a fume hood fo r the following steps:
Choose a chromatographychamber. A 4 L beaker works well, but any large glass container can be used. It is best if clear glass is used so that you can watch the chromatogram develo~. Put the chamber into the fume haod. and turn the haod on. Put on rubber gloves and safety'glasses Pour methanol or ethanol solvent mro the contamer to n helght of about 1 2 in. Thcse solventsare toxic. Avoid breathing t h e solvent vapors. 'Put the bottom of the T-shirt into the beaker, being careful not to let the solvent touch the dots of ink. Lower the shirt until the solvent is just below the dots. Let the top of the shirt hang out over the edge of the heaker. Cover with a watch glass, a plate or bowl, or a piece of plastic wrap. Let chromatogram develop from 5 3 0 min. Leave it...