This document describes experiments analyzing the herbicide atrazine using two green chemistry analytical techniques: dispersed liquid-liquid microextraction and headspace liquid phase microextraction. It outlines the steps for each technique, presents results on extracting atrazine with different solvent combinations, and concludes that 45 μl chlorobenzene and 100 μl methanol were the most effective combination for dispersed liquid-liquid microextraction.

1. Analysis of Atrazine Using
Dispersed Liquid-Liquid
Microextraction and Headspace
Liquid Phase Microextraction
Eleanor K. Skelton
Owens Research Group
CHEM 4980, Merck Research Methods
University of Colorado at Colorado Springs
April 23, 2012

2. Outline
- Properties of Atrazine
- Two Green Chemistry Analytical Techniques
• Dispersed Liquid-Liquid Microextraction
• Headspace Liquid Phase Microextraction
- Published Literature on each
- Experimentation with each method
- Results and Conclusions

3. Project Goals
- The compound atrazine
and its harmful properties
- Two “Green Chemistry” techniques to
analyze concentrations of atrazine in our
water supply

4. Background and Technique
Overview

5. Dispersed Liquid-Liquid Microextraction

6. Step 1:
Pipet 800 18 MΩ μl DI water, 200 μl
dispersive solvent (methanol in our
experiments), and 30 μl extraction
solvent (chlorobenzene) into 1.5 ml
microcentrifuge tubes.

7. Step 2:
Sonicate for five minutes

8. Centrifuge (with microcentrifuge
Step 3: tubes balanced) for three minutes.

9. Headspace Liquid Phase
Microextraction

10. Step 1: Fill 250 ml beaker with 18 MΩ DI
H2O and partially submerge
headspace vial, which also contains
18 MΩ DI H2O. Place stir bars in
each. Set stir bar knob about 700
rpm. Heat may or may not be used.

11. Fill syringe with 1 μl 1-octanol, and inject
Step 2: through septum of headspace vial.

12. Step 3:
Suppress plunger of
syringe until one
droplet appears.
Time system for five
minutes, then draw
Droplet
droplet back up into
syringe for GC/MS
analysis.

13. Inject samples into brown glass sample
vials with glass inserts for GC/MS analysis.

14. Results
Amount of MeOH % Recovery Amount of CB % Recovery
50 μl 229.3%
100 μl 135.4% 15 μl 310.56%
150 μl 50.6% 30 μl 182.71%
200 μl 24.2% 45 μl 89.94%
300 μl 47.0% 60 μl 40.02%
500 μl 40.8%

15. Conclusions
• 45 μl chlorobenzene and 100 μl methanol are the most
effective combination of dispersive and extraction
solvents tested for atrazine analysis.
• The 200 μl samples of methanol as the dispersive solvent
will be reprocessed to obtain more accurate data.
• Future experiments will use these amounts as we attempt
to extract atrazine from non-standard solutions.
• This summer, we will collect samples from various
watersheds to observe concentrations of atrazine are
present in and around El Paso County.

16. Acknowledgements
-
- Dr. Janel Owens
and her research group
y own work unless otherwise noted.

17. References
1. Albanito, L.; Lappano, R.; Madeo, A.; Chimento, A.; Prossnitz, E. R.;
Cappello, A. R., Dolce, V., Abonante, S.; Pezzi, V.; and Maggiolini, M.
Environ Health Perspect. 2008, 116, 1648–1655.
2. Van Leeuwen, J. A.; Waltner-Toews, D.; Abernathy, T.; Smit, B.; and
Shoukri, M. Int. J. Epidemiol. 1999, 28, 836-840.
3. Deegan, D. EPA. EPA. 2003, Press Release. Web. Accessed 23 April
2012.
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562e7004dc686/604c8f5a426eb14085256cbf0070e94a?OpenDocume
nt>
4. Chandrasekaran, K.; Karunasagar, D.; and Arunachalam, J. Anal.
Methods. 2011, 3, 2140.
5. Yang, P.; Ren, H.; Qiu, H.; Liu, X., Jiang, S. Chemical Papers. 2011,
65, 747–753.
6. Nazarenko, A. American Laboratory. 2004, x.
7. Ma, J.; Lu, W.; Li, J.; Song, Z.; Liu, D.; and Chen, L. Analytical
Letters. 2011, 44, 1544-1557.
All photography was my own work unless otherwise noted.