D. C. Neckers,' Max 6. D u n ~ a n , ~ James Gainor2 and Peter B. Grasse2 Bowling Green State University Bowling Green. Ohio 43403
Cost Effectiveness in the Organic Laboratory
The cost of individual experiments has been a concern of those in charge of organic lahoratories ever since the first purchase reauisition was nresented to a department chairman. buring recent years t h e - ~ r a hoil embargo has had an additional maior impact on American universities and the cost of organic chemistry instructional programs. Largely due to the increased cost of petroleum crude, the prices of organic chemicals have been seen to double, or sometimes even triple, in the last several years.3 As part of a summer project encouraged by the inordinately increased costs of teaching our organic lahoratories, a group of three students workedthroueh a series of tvnical uudergraduate laboratory experimen& to see if saGigs could he effected by better procedures. The students were asked to find out how undergraduate students could be encouraged to he less wasteful in their undergraduate organic laboratory. A side benefit, we anticipated, was that universities might add their bit in the conservation of small auantities of netrochemicals. We reasoned that classical instruction in undergraduate labs and the rather lax attitudes to which we had Gown accustomed in the 1960's might no longer suffice in the 1980's. We wanted to search out raw materid saving techniques. In approaching the problem, undergraduates from three midwestern liberal arts colleges joined my department foian eight-week investigation of the question-how wasteful are undergraduate oreanic laboratories. and whv? Thev were askedto think about ways the typicai undergraduate iahoratorv could operate more conservativelvwithout sacrificine the basic reason for the exercise in the first place-the pedagogical value of the experiment. The idea was to study, carefully, a host of undergraduate laboratory manuals, asking the specific question-just what does a particular organic laboratory experiment cost when considered on a total cost effectiveness hasis? All aspects of expense, including utilities, were analyzed as we tried to determine just where the money went in an organic lab. After our cost analysis was completed, we next looked a t simple ways to save costs by recycling or decreasing quantities of crucial reagents used for the experiment.
Results About 50 undergraduate laboratory experiments from seven different popular laboratory manuals were cost analyzed. A simple form, shown below, was designed and the students worked directly with the departmental administrative assistant seeking his experienced advice on the purchasing of re.nlacement chemicals-at the best orice--for a medium-sized university operation. Chemical prices were also compared with the minimum available orices:. i.e... when the chemicals were purchased in large, hulk quantities. ~~
Experiment Title: Caffeinefrom Tea A. Cost AnalysisIStudent Materials 10 Tea Bags 25 g Calcium Carbonate 50 ml CHCh 5 ml Benzene 1rnl Ligroin Utilities: 1hour gas 20 min water 690 / Journal of Chemical Education
Cost of Typlcal Organic Experiments
Wdroiysis; Oil of Wintergreen Preparation of Aspirin Hippuric Acid Caffeine from Coffee Synthesis of Benzoic Acid 2-Chiomnaphthalene Tetraphenyicyciopentadienone
Ref.
Costlstudent
a a b b c c c
$0.25 0.03 1.39
0.55 2.02
1.65 0.98
Bresrter, R. 0.. ~ c ~ w e W. n . E.. and Vanderwed, c A., "unitized ~xperimentsin Orgsnic Chemistry." van Nosmod, 1969. "ohrig. J. R.. and Neckerr. D. C.. "Lab Experiments in Organic Chemiatry." Van Nosband. 1973. 'FMer, L. F.. and Williamson. K.. "Exwiments in Organic Chemirtry." Hwfh. 1975.
Time: 3 hours-4 hours if crude caffeine is purified by sublimation Total: Adjusted for 25%waste $0.35/student $-0.12lstudent hour Recovered: 75%CHCh (35ml) savings by solvent recovery $0.08 The use of utilities required for organic experiments was similarly analyzed. The liters of gas required to operate a typical Bunsen burner on a per hour basis were measured and the cost compared with that of a heating mantle or steam bath used for the same experiment. Even the water flow, for condensers, and the costthereof, was analyzed. Analyses of some typical experiments from selected manuals are given in the table. The conclusions are best summarized as follows: (1) utility costs, a t t h e moment, are still insignificant on a per student basis; (2) the most expensive reactions are those requiring expensive inorganic reagents, or large volumes of costly solvents; and (3) an average cost of 50$/student/4 hr laboratory is about averaee .lab " for the experiments in contem~oraw manuals. Having cost analvzed the experiments the students next asked-aoes it havk to he that way? Are there procedures which can he written into curricular or individual experiments which save materials and money but do not harm the pedagogical value of the experiment? T o answer this question, we set about cost saving devices for undergraduate lahoratories. Though, on a per student basis, 50dlah seems small, the accompanied loss of petroleum based solvents and chemicals is not always small. When multiplied over the approximately 500.000 students who take some kind of oreanic chemistrv lah&atory each year, the materials wasted d k i n fact, become significant. Typical devices conceived by the students for cost-savings are not particularly novel, nor are they unique. When applied on an extensive basis, however, they could effect natural re'Fellow of the Alfred P. Sloan Foundation 1971-1976. %N.S.F.Rule Summer Scholars-1976. :'We have made extensive analyses of organic costs. As near as we can make out 100%is the typical cost increase for organics during the last three years. Many chemicals have increased even more than that.
source conservation. More importantly, concern with the project enhanced the awareness of t h e participating students toward conservation of materials and cost accountinn-an i m p o r t a n t benefit which all undergraduates should realize. S o m e t v d c a l examples devised bv t h e participants for cost savings are shown heiow. Recycling Eachof the threestudents took itupon himself to routinely recycle allof his solvents and, where necessary, herewrote that portion of his experiment to recover solvents. Consider an example: virtually every elementary teaching organic laboratory uses the extraction of caffeine fromeither coffee or tea to instruct in the technique of immiscible solvent extraction. In an experiment in which caffeine is isolated from tea leaves436 ml of chloroform is utilized in removing the caffeine from the aqueous phase. But what happens to the chloroform when the experiment is completed? It is distilled away and simply drawn off into a water aspirator where i t becomes part of the discarded waste. A similar experiment involving coffee rather than tea" is done on a slightly larger scale. Chloroform (60 ml per student) is required. Again, the chloroform is distilled away after the extraction procedure and completely wasted. Spot checks of six or seven laboratory procedures using the same kind of experiments to illustrate the principles of extraction give exactly thesame result. At the end of the experiment the solvent is destroyed, becomes part of the waste, and is lost. If we assume that, annually, 10,000students in the United States use the experiment4 for their organic chemistry courses (this is not an unrealistic number) and if we also assume that 10,000 students use the alternate experiment and isolate caffeine from coffee, the wasted chloroform, nationwide, in the first experiment is 360 1, while 600 1 of chloroform is wasted in the extraction of caffeine from coffee. In just two experiments carriedout by 20,000students in our nation's uniuersities, failure to recycle has cost the world ouer 1000 1 af chloroform! Since the chloroform was probably purchased on a relatively small scale, these two experiments alone cost our nation's universities about $5,000! Multiply the number of students who have carried out these experiments each year by the lifetimes of these laboratory experiments and you see that substantial savings, both in materials and dollars could have been made had the writers of the experiments written in a simple recycling step a t the end of the experiment instead of flash evaooratine the chloroform. A simole vacuum distillation could have
be the same. Carrying Out Experiments in S e q u e n c e s Another materials and cost saving device used by the three students was to carry out experiments in sequence. Their idea again was not particularly unique, but the fact that they came up with i t independently was and shows again the value of the experience in their preview of organic laboratories. For example, one student spent one routine laboratory session on the sequence of experiments."
benzene (just add bNH, to solution of boiling b. then cool)
I
1
*NHz
succinanil C1 Each u l the three reartims i, .ihort. No rwryitallirariuns w r r req.~ired.The licldr i t ) the steps were ~xrrllent.%, 98, and 6(% in11the meroll sequence waq nor part~rularl)expeusiw, r u n n ~ n gahour 45c
per student per experiment, but the sequence was not gratifying for the student. At the end he searched and searched for uses of succinanil, without any success. The product of thesequence was useless, basically, so the sequence lost a great deal of its pedagogical ap"~111. r---
This was the take-home lesson for the student-that making useful products is more fun than just making products to carry out a sequence of experiments to learn techniques. Making Useful Products Perhaps most ingenious of the students collective summer was their suggestion that, as a group, they could make products for commercial sale. Two kinds of projects were considered 1) Those which produced an unavailable, but marketable product 2) Those in which the group synthesized a commercially expensive product from cheap starting materials
Both approaches were extremely gratifying in the end and proved most interestine for the students. Consider the first: /',I"-Ji-rcrr-btjrvlhlphenylappeared in the Ilteraturethis\pring7 and appear.tudent spent abuut 1 ureks working most important take-home lessan. at the proh.em: how uor, itilbenr add photoehern~cally1.1 itilhene' A second student approached the problem somewhat differently. In the end he devised an entire laboratory sequence of experiments He reasoned that many undergraduate experiments are performed which a small group of undergraduate students could carry out. routinely without regard far profitability. As such, he also reasoned The take-home lesson from his experience was also not particularly that routine undergraduate experiments which produce products unioue-thoueh it reinforces aeain the concent of oroiect orientation whieh cost more than thestarting materials should he better experiin tAe oreanic"lahoratorv andthe fact that''1ess.i~ &en more:' A ments than those which produce products whieh are less expensive than the materials from which the products are prepared. As such, he first analyzed a series of Grignard experiments excerpted from common laboratory manuals. Almost to the experiment of natural resources he found that the experiment produced a relatively cheap product Summary and Conclusions from a reasonably expensive starting material. For example, a typical Grignard experiment found in many undergraduate laboratory Few pedagogical experiences in t h e principal investigator's manuals prepares henzoie acid from bromobenzene. Since bromocareer have beeu a s rewarding as this one. Organic chemistry benzene costs =$8 a kg and benzoie acid $5 a kg, and because one is students are often ignorant of t h e value of t h e supplies they limited toa 75% weight efficiency anyway by virtue of the difference consume a n d t h e natural resources they require. Most exin molecular weights of bromobenzene and benzoicacid, the experineriment writers in t h e v a s t have been euiltv. of takine for ment is a cost inefficient one. You lose money by performing it. granted t h e unending supply of petroleum-based materials. .An i l b \ ~ w s l ?l~ettrrrxpmmmt X O U I ~ be to prrpare p-ch1s.11)W e therafore are neelieent i n our instructional d u t v uiz a uiz b r w k 3c1d(,$I:> ltdlp, trorn p-bmmt,chl
