T-shirt Chromatography A Chromatogram You Can Wear Jeanne M. Buccigross College of Mount St. Joseph, Cincinnati, OH 45233-1670 Chromatography is a n important technique used by chemists to separate mixtures ofchemicals 11,. P a ~ e r c h r o matography &felt tip pens and marker inks i s popular lab activity for v .ouw .. children (2.3).Chalk chromatomaphy of felt-tip markers uslnfi methanol 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-shirt chromatograms 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.
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Two Methods for T-shirt Chromatograms This paper presents two methods for producing "stateof-the-art" T-shirt chromatograms. .The first method 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 to make these chromatograms pwmanent. Caution
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markers.. reauires the use of Method 1. usine .. nermanent . 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.
Method 1: Permanent Markers
Materials permanent felt tip markers (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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Procedure Wash and dry your T-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 going through to the back. Choose " vour Dens. . Use ones which sav "nermanent." Sharnie 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 f o 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 solvents are 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 in the hood durinc this time. ~ e m o i vour e chromatoeram from the solvent. and let it dm completeiy. This shouli be done in the fume'hood to avoih prolonged breathing of the methanol or ethanol vapors.
Volume 69 Number 12 December 1992
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After the T-shirt has dried completely, it can be made more permanent by treating it with Jo Sonja textile medium. To use this, mix the medlum with water 1:l. Paint the medium onto the chromatogram patterns. Let dry completely (24 h). Heat treat with an iron as described on the package, ar heat treat by placing the shirts in a clothes dryer for about 30
min. Your T-shirt chromatogram is now ready to wash and wear! Method 2: Water Soluble Markers Materials water soluble frlr tip mnrkcrs Flair. Expresso eV.l ST-shm,prewauhed 4 - Lbeaker or other glass container watoh glass or plate to mver beaker .water Jo Sonja textile medium (essential) Procedure: Follow directions for permanent markers with changes in the steps listed below:
Use water soluble rather than permanent pens. Flair works well, especially green, orange, black, and blue. Expresso pens also work well, especially brown, green and black. The black Expresso is very different from the black Flair. This makes an interesting comparison. Use water rather than methanol or ethanol as the solvent. The fume hood and gloves are not needed. Chromatogram will need at least 30 min to develop well. Because the solvent is water, you do not have to worry about the vanors. Hane the Trshirt on a clothes line or on a clothes hanger to dry. The T-shirt MUST be treated with J o Sonia textile medium to be permanent. Use t h e fabric medium full strength. Do not dilute. Paint it onto the shirt as above. I t may cause a small amount of bleeding in the chromatogram.
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Results and Discussion Method 1
The Dermanent markers s e ~ a r a t auite e well. and sometimes into surprising colors. Scparation can be observed in as little as live minutes. hut 2 0 3 0 mln. wlll allow the colors to migrate further. In spite of the claim to be "permanent", some of the colors will fade, and the lighter shades that appear during the chromatography will be lost if the T-shirt is laundered in warm water without being treated with the textile medium. This makes the separation less obvious in most cases. Treatment with Jo Sonja textile medium makes the colors permanent even with repeated laundering, and so should be used when practical. Laundering in cold water will help to preserve the colors if the textile medium is not available. The major disadvantage of this method is the use of organic solvents and the resulting need for safety precau-
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tions. Both solvents are toxic and so the vapor must not be inhaled. This requires the use of fume hoods. Roth solvents can he absorbed through the skin and so thestudents must wear rubber gloves when handling the solvent or the wet T-shirts. Safety glasses should be used to avoid splashing solvent into the eyes. Method 2 The water soluble inks migrate well, but are not well resolved. They tend to separate into narrow overlapping bands just below the solvent front. These chromatograms require a minimum of 30 min to develop. They must be treated with Jo Sonja textile medium or they will wash out as soon as exposed to water. The medium must be used full strength or the color will fade with each washing. The full strength polymer prevents color loss, but i t makes the shirt feel a little stiff where it has been treated. The advantage of the water soluble system is that it is completely safe and nontoxic (if nontoxic markem are used) and does not require a fume hood or gloves. J o Sonja textile medium (Chroma Acrylics Inc., Hainesport, NJ 08036) can be purchased in most craft stores and in some a r t supply stores and fabric shops. Shops that sell supplies for T-shirt painting are the best bet. The fmished T-shirt can be decorated by using a permanent marker or T-shirt painting supplies t~ paint a title, the solvent used, the colors under each pen etc, that you might find on a chromatogram processed in any lab. There are many possible variations to these methods e suszested modthat can be tried. and several ~ e o d have ifications. The method presenied here was de&loped to be e schromatoera~hv used to ex~lainthe ~ r i n c i ~ l of - . . ( 1 1and represent the manner in dhich chromatograms are set up by chemists. More artistic arrangements are possible and employ the same principles, but will no longer look like chromatograms that could be found in any chemistry lab. For the more artistic reader, the following suggestions have come from my audiences: radial chromatography using a filter paper wick in the middle of the shirt, random placement of the spots, the child's names rather than spots, mixing permanent and water soluble pens for the same shirt, etc. Many more variations are possible. It also is possible to use media other than T-shirts. Quilts made of blocks of radial chromatograms and canvas sneakers have been prepared by others using the method presented here. Literature Cited 1. Ebbing, D. D. Cpmml Chemlalq, Md.; Hrmghton M i m Company: Boston, 1990: pp 3a.39. 2. Bargford, C. L.; Summerlin, L. R. Chrrniml Aetiuitim % e b r Edition: Ame"ean Chemical Saciety: Washingtan, DC. 1988; pp 251-258. 3. Duersf M. J. Chem. Edue. 1990.67, 1031. 4. Bargford, C. L.; Summedin, L. R. Chemiml Adiuifks: k h e r Ediflon: American Chemical Saciety: Washington. DC, 1988: pp 25?-260.
