The Perils of Drinking Water
A Teaching Module on Analytical Chemistry Techniques for Determining Drugs in our Drinking Water
Fredrick G. Hurtado1
Nicholas H. Snow, Ph. D.2
2 Department of Chemistry and Biochemistry, Seton Hall University, South Orange, NJ
Summer Research Program for Science Teachers
Module Topic: This teaching module was created to introduce high school students to current analytical chemistry techniques employed in the research laboratory as well as raise awareness of the current problem with pharmaceutical-tainted waters. The analytical techniques utilized were slightly modified for the high school classroom without compromising the concepts. These techniques highlighted in the module can be used to introduce several topics that include: Solution concentrations, solution stoichiometry, dilutions, Beers Law, equilibrium, drug delivery, absorption, adsorption and environmental concerns.
Appropriate Subject Area(s): Advanced Placement Chemistry, Honors Chemistry and College Preparatory Chemistry.
Rationale: Chemistry practiced in the research laboratory and the manner in which it is taught to the adolescent student is far too incongruent. This is a serious problem for a society that is dependent upon knowledge that is current and complete. Moreover, the problem becomes very serious when the secondary education preparation and the college expectations do not align. Therefore, a structural change, a shift in the approach chemistry is transmitted and integrated within the k-12 curricula must take place. An inquiry-based laboratory exercise such as the one proposed here can serve as an initial step toward such a change. It is extremely important to expose students to this kind of rich curriculum; that allows them to be in control of their own learning. Students must be prepared to be independent thinkers, to make informed decisions concerning human activity and the consequence that it has on the environment, and understand the interrelationship between science and technology. In a research curriculum students learn by discovering—being captivated and become engaged in doing science.
Students will be able to:
1. Use appropriate laboratory safety procedures.
2. Utilize proper laboratory equipment
3. Construct laboratory equipment
4. Compose a polarity chart for chosen analgesics
5. Create a calibration curve for a specific analgesic
6. Calculate values from experimental measurements
7. Interpret data from graph
Background Information: Pharmaceuticals and personal care products, known in the water industry as PPCPs, have been detected in trace amounts in surface water, drinking water and wastewater effluent sampling conducted in both Europe and the U.S. Environmental Health Perspectives informs in 2005, on the over 100 pharmaceuticals that have been found in rivers, lakes and coastal waters throughout Europe and the U.S. (Hemminger, 2005). Further research suggests that there may be some ecological harm when certain drugs are present. Chemistry and Ecology reported in 1994 on the feminization of male fish as the result of exposure to sewage effluent now known to contain ethinyl estradiol, the active ingredient in birth control pills (Hemminger, 2005). To date, however, no evidence has been found of human health effects from pharmaceutical and personal care products in the environment; this includes drinking water sources. The issue, however, becomes grave when one reasons the effects that the long-term exposure to these contaminants can have on people’s health. To date, no studies on the long-term exposure-effects that trace pharmaceuticals can have on human subjects have been conducted. It would require 3, 4 or 5 decades of data to better analyze the effects. We just have not had the information for that long a time.
There is no debate, however, that throughout several major U.S. cities these chemicals are present in our drinking water sources. The media first began aggressively reporting on detection of pharmaceuticals in our drinking water sources as early as March 2008, in spite of the problem having been recognized more than a decade earlier. As late as July 2008, newspapers were still reporting on antibiotics, anticonvulsants, mood stabilizers, analgesics and sex hormones that had made their way to our drinking water sources.
When pharmaceutical products are consumed, 80% or more of the drug can pass through the body unaltered (Halling-Sorensen, 1998). As the drug is biotransformed, the metabolites can be more bioactive than the drug itself. Wastewater-treatment plants are ill equipped to eliminate these contaminants. As the water is recycled, it makes its way back for human consumption. In a 2002 study, Clofibric acid, Aspirin, Clofibrate, Ibuprofen, Caffeine, Gemfibrozil, Naproxen, Carbamazepine, Ketoprofen, and Diclofenac, were found in the waters of the Seine River near Paris, France (Togola, 2007). These and many other drugs have also been found in U.S. cities.
To study the procedures and techniques utilized in the research laboratory to detect pharmaceuticals in our drinking water, a study using over-the-counter (OTC) drugs will be performed in the high school laboratory. Qualitative and quantitative analyses will be carried out where identification, confirmation and quantitation of the drugs will take place. Mock tainted-water samples will be analyzed for contaminants. The contaminants will be identified from a set of standards in a thin-layer chromatography analysis. The contaminants will then be isolated using column chromatography. Finally, the concentration will be determined visually using a colorimetric analysis using a spectrophotometer.
Approximate Time Required: One to two weeks, depending on the laboratory schedule. One week is better for the standard solutions. If the study must be scheduled to two weeks, make sure to make new standard solutions for week two.
Materials: OTC drugs-diphenhydramine, loratadine, mezicline
tainted water samples (teacher should prepare these solutions ahead of time)
thin layer chromatography plates
capillary tubes or Pasteur pipettes
solid iodine chips
large test tubes
small borosilicate test tubes (cuvettes)
Scenario: You have obtained some water samples from local bodies of water suspected of being contaminated with antihistamines, and antiemetic drugs. Initial tests suggest that the specific drugs may be diphenhydramine, loratadine or meclizine (all available as OTC drugs). You now have the task of determining which drug(s) is/are present in the water and to what extent. Therefore, you have to identify and quantify the contaminants.
Part I: Making standard solutions and identifying the drugs.
Rf = Distance traveled by the compound
Distance traveled by the solvent front
Part II: Isolating the contaminants.
Part III: Colorimetric Assay
Part A: Optical Activation of drugs.
Part B: Serial Dilution, Calibration Curve and Quantitation of Drug Sample.
NATIONAL SCIENCE EDUCATION STANDARDS:
PROGRAM STANDARD A:
All elements of the K-12 science program must be consistent with the other National Science Education Standards and with one another and developed within and across grade levels to meet a clearly stated set of goals.
PROGRAM STANDARD B:
The program of study in science for all students should be developmentally appropriate, interesting, and relevant to students' lives; emphasize student understanding through inquiry; and be connected with other school subjects.
PROGRAM STANDARD C:
The science program should be coordinated with the mathematics program to enhance student use and understanding of mathematics in the study of science and to improve student understanding of mathematics.
PROGRAM STANDARD D:
The K-12 science program must give students access to appropriate and sufficient resources, including quality teachers, time, materials and equipment, adequate and safe space, and the community.
PROGRAM STANDARD E:
All students in the K-12 science program must have equitable access to opportunities to achieve the National Science Education Standards .
Schools must work as communities that encourage, support, and sustain teachers as they implement an effective science program.
NEW JERSEY CORE CURRICULUM CONTENT STANDARDS: (NJCCCS)
STANDARD 5.1 (Scientific Processes) All students will develop problem-solving, decision-making and inquiry skills, reflected by formulating usable questions and hypotheses, planning experiments, conducting systematic observations, interpreting and analyzing data, drawing conclusions, and communicating results.
STANDARD 5.3 (Mathematical Applications) All students will integrate mathematics as a tool for problem solving in science, and as a means of expressing and/or modeling scientific theories.
STANDARD 5.4 (Nature and Process of Technology) All students will understand the interrelationships between science and technology and develop a conceptual understanding of the nature and process of technology.
STANDARD 5.6 (Chemistry) All students will gain an understanding of the structure and behavior of matter.
STANDARD 5.10 (Environmental Studies) All students will develop an understanding of the environment as a system of interdependent components affected by human activity and natural phenomena.
1) Crimi, Christina M. and Snow, Nicholas H. “Analysis of Pharmaceutical Residual Solvents Using Comprehensive Two-Dimensional Gas Chromatography.” (2008) Chromatography Online.com The Website of LCGC North America.
2) Frutos, P. Torrado, Susana. Perez-Lorenzo, M.E. and Frutos, G. “A Validated Quantitaive Colorimetric Assay for Gentamicin.” (2000) Journal of Pharmaceutical and Biomedical Analysis 21:1149-1159.
3) Halling-Sorensen B, Nielsen SN, Lanzky PF, Ingerslev F, Holtem Lutzhoft HC, Jorgensen SE (1998) Chemosphere 36:357-393.
4) Hemminger, Pat. “Damming the Flow of Drugs into Drinking Water.” Environmental Health Perspectives. Volume 113. No. 10. October 2005.
5) Librera, William L. Ed. D. “New Jersey Core Curriculum Content Standards for Science.” (2004) New Jersey Core Curriculum Content Standards. PTM# 1505.24:E1-E27.
6) Snow, Nicholas H. “Determination of Free-Energy Relationships Using Gas Chromatography.” (1996) Journal of Chemical Education 73:592-597.
7) Togola, Anne and Budzinski, Helene. “Analytical Development for Analysis of Pharmaceuticals in Water Samples by SPE and GC-MS.” (2007) Analytical and Bioanalytical Chemistry 388:627-635.
8) The United States Pharmacopeia–National Formulary (USP–NF). The Official Compendia of Standards, USP 29-NF 24 2005. Pharmacopeial Convention Inc., November 2005. USP <467>.