Talk dirty to me: Teaching undergraduate students the importance of good hygiene in

the teaching laboratory

Luke Gallion, Dr. Michael Samide, Dr. Anne Wilson

Butler University, Department of Chemistry Indianapolis, IN

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Presentation Outline

•  Significance of teaching undergraduates the importance of a clean lab

•  Previous work/current practices •  Butler University’s current laboratory

sequence •  Modified laboratory sequence •  Effects of the modified laboratory

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http://searchpp.com/messy-laboratory/

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Significance •  Cleanliness and its

safety impacts lead to success in the laboratory

•  “Maintain proper PPE” and “accident avoidance” ranked two highest safety priorities by industrial chemists

Fair, J. D.; Kleist, E. M.; Stoy, D. M. J. Chem. Educ. 2014, ASAP. DOI: 10.1021/ed400570f. http://www.amazon.com/Simpsons-Chemical-

Safety-Poster-Procedures/dp/B00BR0B9VG

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Previous Work – University of Kentucky

Safety in the Analytical Laboratory: Guidelines and Practices. www.chem.uky.edu/courses/che226/003-Safety_Guide.pdf (accessed November 25, 2014).

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•  Safety guidelines are comprehensive but discuss what to do after an incident, not how to prevent

Previous Work – Iowa State University

•  Great for cataloging safety issues

•  Can be boring and dry

•  Only reading it

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Miller, G. J.; Heideman, S. A.; Greenbowe, T. J. J. Chem. Educ. 2000, 77, 1185-1187.

Previous Work – Seattle University

•  Held a safety training session – Alternate class discussion and worksheets – Students more engaged by breaking up

discussion and worksheets •  Safety teams •  Weekly pre-lab safety presentations

Alaimo, Peter J.; Langenhan, Joseph M.; Tanner, Martha J. J. Chem. Educ. 2010, 87, 856-861.

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Our Current Lab Sequence – Butler University

•  Week 1: Check in, fermentation (aqueous sugar and yeast) set-up –  20 minutes

•  Week 2: Filter solution, perform fractional distillation on filtrate –  3 hours

•  Week 3: Identification of unknown compound using melting point, TLC, and mass spectrometry –  2 hours

Azman, A. M.; Barrett, J. A.; Darragh, M.; Esteb, J. J.; McNulty, L. M.; Morgan, P. M.; O’Reilly, S. A.; Wilson, A. M. J. Chem. Educ. 2013, 90, 140-141. 8

Modification •  Week 1: Check in, fermentation (aqueous sugar and

yeast) set-up –  Pour TLC plates –  Evaluate cleanliness of laboratory –  2.5 hours

•  Week 2: Filter solution, perform fractional distillation on filtrate –  3 hours

•  Week 3: Identification of unknown compound using melting point, TLC, and mass spectrometry –  Compare commercially-available TLC plate to hand-

poured TLC plate –  2.5 hours

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Procedure for Student-Poured Plates

•  1.2 g silica •  0.1 g CaSO4

•  Fluorescence indicator green 254 nm

•  2.7 mL H2O

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Qualitative Results – Week 1

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Qualitative Results – Week 1

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Qualitative Results – Week 1

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Qualitative Results – Week 1

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Qualitative Results – Week 1

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Qualitative Results – Week 1

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Qualitative Results •  “It was helpful to see how the plates are made/work.

However the homemade plates were a lot more difficult to use and I didn’t get any date for one of my compounds.”

•  “Homemade TLC plates, in my opinion, don’t work as well as pre-made TLC plates”

•  “Home-made plates are extremely fragile and therefore not reliable as some completely fell apart. Stick with the purchased commercial plates.”

•  “The TLC plate I made fell apart when I placed it inside the beaker to run.”

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Qualitative Results

“Luke is cute”

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Quantitative Results  

Mean scores 1= “Not Clean,” “No impact,” “Not worthwhile”;

6= “Very Clean,” Strong Impact,” “Very Worthwhile”  

Survey Statements for Response  

Students That Performed Modified

Laboratory  

Control Group Students  

p Values (Significance)  

How would you have rated your lab cleanliness before

this laboratory?  4.45 ± 1.15   4.93 ± 1.03   0.0817,

significant  

Indicate how this laboratory affected your view on lab

cleanliness.  4.42 ± 1.36   3.47 ± 1.55   0.0266,

significant  

Now that you know how a TLC plate is prepared, how worthwhile is it to purchase

commercial plates?  

5.19 ± 1.07   3.60 ± 1.68   0.0016, significant  

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Quantitative Results

  Correct Response, %    

Survey Question  Students That

Performed Modified Laboratory  

Control Group   p Values (significance)  

Rf Calculation   93.5   80.0   0.0869, significant  

Rf understanding   80.6   73.3   0.2925, not significant  

Polarity/IM forces   71.0   33.3   0.0072, significant  

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Summary/Conclusions

•  Greater appreciation of lab cleanliness in hoods and common areas

•  Greater realization of the importance of PPE

•  Greater understanding of TLC •  Greater appreciation of common

laboratory techniques

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Acknowledgements

•  Butler University Department of Chemistry •  Professor Kelsie Graham •  Dr. Michael Samide •  Dr. Anne Wilson •  ACS National Meeting & Exposition •  You!

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References 1.  Banholzer, W. F.; Calabrese, G. S.; Confalone, P. Chem.

Eng. News 2013, 91 (18), 2. 2.  Laboratory Safety. http://www.acs.org/content/dam/acsorg/

about/governance/committees/training/acsapproved/degreeprogram/laboratory-safety.pdf (accessed November 19, 2014).

3.  Fair, J. D.; Kleist, E. M.; Stoy, D. M. J. Chem. Educ. 2014, ASAP. DOI: 10.1021/ed400570f.

4.  Alaimo, Peter J.; Langenhan, Joseph M.; Tanner, Martha J. J. Chem. Educ. 2010, 87, 856-861.

5.  Miller, G. J.; Heideman, S. A.; Greenbowe, T. J. J. Chem. Educ. 2000, 77, 1185-1187.

6.  Hill Jr., R. H.; Nelson, D. A.. Chem. Health Safety, 2005, November-December, 19-23.

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References 7.  Laboratory Health and Safety Training. https://www.amherst.edu/media/

view/64011/original/Laboratory%2BHealth%2Band%2BSafety%2BTraining.doc (accessed November 19, 2004).

8.  The Chemical Safety Mechanism; Laboratory Housekeeping. http://www.ehs.wisc.edu/chem/LaboratoryHousekeeping.pdf (accessed November 19, 2014).

9.  Safety Policies – College of Life Sciences. http://lifesciences.byu.edu/safety/LabSafety/SafetyPolicies.aspx (accessed August 22, 2014).

10. Safety in the Analytical Laboratory: Guidelines and Practices. www.chem.uky.edu/courses/che226/003-Safety_Guide.pdf (accessed November 25, 2014).

11.  Miller, G. J.; Heideman, S. A.; Greenbowe, T. J. J. Chem. Educ. 2000, 77, 1185-1187.

12. Azman, A. M.; Barrett, J. A.; Darragh, M.; Esteb, J. J.; McNulty, L. M.; Morgan, P. M.; O’Reilly, S. A.; Wilson, A. M. J. Chem. Educ. 2013, 90, 140-141.

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Fluorescent Green Indicator

•  Zinc silicate, Mn doped •  Zn2SiO4

•  http://www.sigmaaldrich.com/catalog/product/fluka/02554?lang=en&region=US

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Previous Work

Hill Jr., R. H.; Nelson, D. A.. Chem. Health Safety, 2005, November-December, 19-23.

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Previous Work – Iowa State University

Miller, G. J.; Heideman, S. A.; Greenbowe, T. J. J. Chem. Educ. 2000, 77, 1185-1187.

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Quantitative Results – Appreciation of laboratory

cleanliness •  How would you have rated your lab cleanliness

before this laboratory?1 = “Not clean” 6 = “Very Clean”

•  Control Group (n=18): 4.93 ± 1.03 •  Students that Performed Modified Laboratory

(n=33): 4.45 ± 1.15 •  p Value: 0.0817 •  Statistically significant at 90% confidence level

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Quantitative Results – Appreciation of laboratory

cleanliness •  Indicate how this laboratory affected your view

on lab cleanliness. •  1 = “No impact” 6 = “Strong Impact” •  Control Group (n=18): 3.47 ± 1.55 •  Students that Performed Modified Laboratory

(n=33): 4.42 ± 1.36 •  p Value: 0.0266 •  Statistically significant at 90% confidence level

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Quantitative Results – Appreciation of common laboratory

techniques •  Now that you know how to prepare a TLC plate,

how worthwhile is it to purchase commercial plates?

•  1 = “Not worthwhile” 6 = “Very Worthwhile” •  Control Group (n=18): 3.60 ± 1.68 •  Students that Performed Modified Laboratory

(n=33): 5.19 ± 1.07 •  p Value: 0.0016 •  Statistically significant at 90% confidence level

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Quantitative Results A student ran a TLC of an unknown compound on a commercial silica gel plate. The distance to the solvent front was 5.0 cm. The unknown compound being analyzed had an Rf of 0.4. How far did the compound travel up the plate? •  Control Group (n=18): 80% correct •  Students that Performed Modified Laboratory

(n=33): 93.5% correct •  p Value: 0.0869 •  Statistically significant at 90% confidence level

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Quantitative Results The student from the previous question (#4) wanted to replicate data. This time, the compound traveled 1.6 cm. What was the distance to the solvent front? •  Control Group (n=18): 73.3% correct •  Students that Performed Modified Laboratory

(n=33): 80.6% correct •  p Value: 0.2925 •  Not statistically significant at 90% confidence level

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Quantitative Results Compound A is very polar. Compound B is nonpolar. Compound C is of moderate polarity. If these three compounds were spotted on a TLC plate and a mobile phase of 90:10 hexanes: ethyl acetate was used, what would be the elution order of the compounds from lowest Rf value to highest Rf value be? •  Control Group (n=18): 33.3% correct •  Students that Performed Modified Laboratory (n=33):

71.0% correct •  p Value: 0.0072 •  Statistically significant at 90% confidence level

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