Quantifying Sucralose in a Water-Treatment Wetlands: Service

Jan 12, 2018 - Participation in service-learning can provide chemistry students the opportunity to develop those skills and better prepare them for th...
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Quantifying Sucralose in a Water-Treatment Wetlands: ServiceLearning in the Analytical Chemistry Laboratory Emily C. Heider,* Domenic Valenti, Ruth L. Long, Amel Garbou, Matthew Rex, and James K. Harper Department of Chemistry, University of Central Florida, 4111 Libra Drive, Orlando, Florida 32816, United States S Supporting Information *

ABSTRACT: Service-learning (SL) is an active learning approach that connects the knowledge a student acquires in the classroom to an application that benefits the community. Increasingly popular in the chemistry curriculum, service-learning is reported to provide student benefits including improved cognitive goals; increased academic, interpersonal, and leadership skills; increased ability to apply course concepts to real-world situations; and increased community engagement. For the work reported here, an analytical chemistry laboratory was modified to include a service-learning component with the goal of allowing students to apply their newly acquired analytical skills to relevant, real-world samples; to learn new analytical techniques; and to develop professional communication skills. Students implemented a study of the wastewater effluent at the Orlando Easterly Wetlands, an engineered water polishing facility that removes nutrients from treated wastewater. Students designed a sampling strategy, collected samples in the field, and performed standard analysis on the water, including pH, chloride, total dissolved solids, and phosphorus. Students also tested the water for the artificial sweetener, sucralose, and characterized the concentration throughout the flow path of the wetlands. Sucralose has been proposed as an indicator of contamination of natural waters by anthropogenic waste. This type of analysis has not been performed for this public utility until now, and the students shared the results in a public seminar. Student learning outcomes were compared to those in a conventional section, with SL students showing comparable subject mastery and improved self-efficacy. KEYWORDS: Upper-Division Undergraduate, Analytical Chemistry, Laboratory Instruction, Communication/Writing, Applications of Chemistry, HPLC, Mass Spectrometry, Professional Development, Water/Water Chemistry, Environmental Chemistry

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creative problem solving, and ability to work collaboratively.4 These skills are not generally emphasized in the undergraduate chemistry curriculum, but may be developed through servicelearning projects. Service-learning in chemistry often involves the development and performance of demonstrations by students in schools or the community.5,6 Others focus on providing a platform for college students to teach primary and secondary school students. For example, Glover et al.7 taught organic chemistry students to synthesize azo dyes, which the college students then used to teach secondary school students about dyes and complete a tie-dye activity. Esson and co-workers8 required introductory chemistry college students to visit an elementary school for 1 h a week over an eight week period and perform chemistry experiments that were accessible in content to younger students. These projects reported increased collegestudent sense of citizenship7 or increased percentage of introductory students pursuing a chemistry terminal degree.8 Increasingly, researchers are seeking ways to combine college-

INTRODUCTION In 1996, the inaugural issue of the Journal of Public Service & Outreach published a posthumous appeal from Ernest Boyer, a renowned educator and advocate for the advancement of teaching. He called for academic institutions to increase public confidence in higher education and to become a “more vigorous partner in the search for answers to our most pressing social, civic, economic, and moral problems”.1 Many instructors and researchers have responded to his invitation to participate in the scholarship of engagement, and successful servicelearning can make strides to answer that call. A mechanism to break the barrier dividing inert disciplinary knowledge from its application, service-learning combines academic study with community service. The results of these efforts have been reported to provide many benefits, such as enhancing student interest, positive attitudes toward community involvement, a better sense of personal efficacy and commitment, problemsolving skills, and formal reasoning ability to cope with illstructured problems.2 Engaging chemistry students in servicelearning may help them prepare for careers as well. Private chemical industries employ roughly two-thirds of chemists in manufacturing and research,3 and the skills recruiters (in the chemical industry) seek most are leadership, communication, © XXXX American Chemical Society and Division of Chemical Education, Inc.

Received: July 28, 2017 Revised: December 13, 2017

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DOI: 10.1021/acs.jchemed.7b00490 J. Chem. Educ. XXXX, XXX, XXX−XXX

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during the semester reported here. Two of the sections were randomly assigned to be standard sections and were taught as usual. The third section was modified to include the servicelearning project. No distinction was made in the course catalog for the sections, and students self-selected into the courses based on their schedules. Students were not assigned into groups, and no efforts were made to sort the students based on grade point average. The distributions of student year in school for the service-learning and comparison sections are shown in the Supporting Information. The major programs of study pursued by the students enrolled were chemistry (43%), forensic science (35%), and biology (22%). The students in all sections were given a pretest covering concentration units (molarity and percent composition), dilutions, standardization, and proportional reasoning. The students in the conventional sections earned an average score of 63 ± 20%, and the students in the service-learning section, on average, scored 60 ± 20%. These pretest scores indicate the populations in the conventional and service-learning sections had comparable baseline knowledge. The laboratory schedule of the service-learning section, with 22 enrolled students, was modified to include a 5-week servicelearning project. The laboratory topics for the traditional and the service-learning section are shown in Table 1. To

student outreach to primary and secondary school students with enhanced college-level learning strategies. Kalivas emphasized science-process skills with discovery laboratories in general chemistry, and then extended the discovery laboratories to teaching K−6 students a concept discovery activity.9 Feedback from college students and the K−6 teachers was overwhelmingly positive, although formal assessment of learning gains was not undertaken. An alternative approach to service-learning in chemistry involves the application of chemical analysis techniques to environmental problems in the surrounding community. Early service-learning work by Kesner and Eyring10 involved general chemistry students contacting the homeowners in nearby neighborhoods, explaining the hazards of lead paint, sampling the home’s exterior paint, and performing a wet-ash procedure to prepare the samples to submit for lead analysis with atomic absorption spectroscopy. The results of the paint analysis were reported by the instructor to the Health Department and letters mailed to the participating householders. Although the students in that service-learning project did not demonstrate better content knowledge than their peers, service-learning students exhibited higher motivation for the lead paint analysis project than for validation experiments with unknowns.10 Also in 1999, O’Hara and Sanborn11 reported introductory chemistry students conducting project-based service-learning activity to analyze pesticides in drinking water. Students sampled water at artesian wells, performed solid-phase extraction to prepare a sample for GC−MS analysis, and used enzyme linked immunosorbent assays to test for endosulfan and DDT. Those students generated a class report, and plans were underway to modify the program to include oral presentations in the future. The work of Draper12 also describes project-based service-learning in an environmental chemistry course, in which eight students researched and selected environmental samples they wished to analyze, and they derived methods of analysis from the peer-reviewed literature. Students then presented their results in a poster session at a meeting, and student perceptions were assessed through surveys, although no formal learning gains were assessed through exams. If service-learning projects can meet the goals of providing a community service, as well as prepare students for future careers, the work of Draper12 seems to offer a more complete approach: one that incorporates a component of students presenting results of the work in a professional setting. In addition to the relevance of conveying discipline content and civic engagement, preparing students to analyze and communicate their results in professional presentations is also important. We report the use of a service-learning project in an analytical chemistry laboratory course that included water sampling and chemical analysis at an engineered wetlands for polishing treated wastewater. Additionally, the students completed oral presentations to the community and city representatives of the water utility, and a results report in a newsletter for stakeholders and subscribers. Finally, the students were assessed with a final exam and the results compared to that of students in other sections of the course.

Table 1. Analytical Chemistry Laboratory Topics by Section and Number of Dedicated Lab Periods Topic Acid/base titration (indicator) Acid/base titration (pH meter) Gravimetric analysis Spectrophotometric analysis/linear calibration Ion-exchange chromatography and EDTA titration Ion-selective electrodes Electrochemical titration Paper chromatography In-field sampling Conductivity/standard addition calibration Solid-phase extraction and HPLC-MS Oral presentations

Traditional Lab Periods

Service-Learning Lab Periods

1 1 1 2

1 1 1 1

2

2

1 2 1 0 0

1 0 0 1 1

0

2

0

1

accommodate the time demands of the project, one laboratory experiment was compressed from two to one lab periods, two laboratory experiments were excluded in entirety, and, due to the holiday schedule, the service-learning lab section had an additional lab period during the semester. Learning objectives for both conventional and servicelearning sections were, in large part, the same. For both sections, students completing the lab should be able to demonstrate knowledge of laboratory safety and professional laboratory behavior, use statistical techniques to analyze data, prepare accurate liquid standards, standardize acid/base solutions using titrimetric analysis, apply stoichiometric (e.g., gravimetric, titrimetric) methods of analysis to determine concentrations of unknown samples, correctly utilize laboratory glassware (burets, volumetric flasks, volumetric pipettes, etc.), and other common laboratory tools (mass balances, spectrometers, pH meters), apply physicochemical (e.g., spectro-

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RESEARCH SETTING The course selected for this community project was a 3000level analytical chemistry laboratory. Students often, but not always, enroll in the laboratory concurrently with an analytical chemistry lecture. Three laboratory sections of the analytical chemistry lab (course number CHEM 3120) were offered B

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photometric, electrochemical) methods of analysis to determine concentrations of unknown samples, use separation (e.g., chromatographic) techniques to obtain samples suitable for chemical analysis, use graphical analysis software, and communicate procedures and results in writing. For the service-learning section, the learning outcomes listed above were supplemented with the following expectations of student skills: the ability to distinguish between homogeneous and heterogeneous sampling procedures, apply analytical laboratory techniques to real and relevant samples, collaborate with classmates to answer a large-scale analytical question by contributing one part of the overall puzzle and sharing the class’ results, gain experience using modern analytical instrumentation, apply multimedia presentation conventions to prepare visual aids for public presentations, and communicate research motivations, methodologies, and outcomes with an oral presentation.

Sucralose (structure shown in Figure 1) is a noncaloric artificial sweetener that is commonly used in diet soda

Figure 1. Chemical structure of sucralose.

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COMMUNITY PROJECT The setting for the project was the Orlando Easterly Wetlands (OEW), a constructed wetlands for removal of nutrients (nitrogen and phosphorus) from treated wastewater. The OEW polishes approximately 14 million gallons of water per day from a wastewater-treatment facility before it flows into the St. Johns River. The aim of the park is the removal of nitrogen and phosphorus below Florida Department of Environmental Protection (FDEP) levels of 2.31 mg/L total nitrogen and 0.200 mg/L total phosphorus. Given this objective of the park, a primary aim of this project was for students to develop an understanding of the purpose of the wetlands by sampling water strategically throughout the park and quantifying the phosphate concentration (using spectrophotometry), total dissolved solids (using conductivity measurements with standard addition calibration), total suspended solids (gravimetrically), chloride ion, and pH (with ion-selective electrodes). That portion of the project did not perform a service because these parameters are regularly monitored by park personnel. Rather, this water sampling and water quality analysis was intended to help educate the students on the water-treatment at the wetlands and to overcome misconceptions about wetlands: Tal reported the common misconception held by college students that consider swamps to be filthy places that should be drained for public health.13 For the service aspect of this work, the OEW personnel were consulted regarding the detection and quantification of analytes that would be of interest to them. The OEW water has previously been studied for past and potential phosphorus removal,14 short-term effects following controlled burns,15 and sludge removal and revegetation.16 Small organic molecules, such as pharmaceuticals, are garnering increasing attention as sources of contamination in treated wastewater irrigation.17 Efforts are underway to characterize small-molecule removal processes in wetlands, such as sedimentation, biotransformation, photolysis, and photoinactivation.18 Wetlands personnel were interested in determining if the artificial sweetener, sucralose, was present in the treated wastewater and whether its concentration is changed by any of the physical, chemical, or biological processes that remove other chemical species from the water. The service was provided in the form of method development for the quantification of sucralose and report of the concentration profile throughout the northern flow train of the park.

beverages, cereals, and sugar-free desserts. In the United States it is marketed in Splenda, where it has been the best-selling artificial sweetener.19 Sucralose is not hydrolyzed in the human intestine, does not bioaccumulate, and is excreted in urine and feces.20 Torres et al.21 report that sucralose is undegraded by common processes in municipal wastewater-treatment facilities, such as aerobic and anaerobic biological reactors, prolonged exposure to ultraviolet radiation, and chlorine or ozone oxidation. As such, sucralose and other artificial sweeteners have been proposed as indicators of wastewater loading in natural waters.22 The presence of artificial sweeteners in surface23 and drinking24 waters is increasingly common, partly due to indications that artificial sweeteners can modify the gut microbiota in mice, leading to glucose intolerance.25 Quantifying sucralose in the tertiary water-treatment wetlands would set a benchmark for sucralose in the treated wastewater, and tracing its concentrations from the inflow, following deep marsh and mixed marsh treatment, and at the outflow would provide insight into whether wetlands processes altered the sucralose content before the water entered the St. Johns River.

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EXPERIMENTAL METHODS

Sampling

One lab period was devoted to sampling at the wetlands park. Students met first in an on-site education center at OEW to devise a sampling strategy in consultation with the course instructor and park personnel. A stratified heterogeneous sampling strategy was selected, with six students sampling at the inflow, five students sampling after the deep marsh (hereafter referred to as site 3Y, according to the park designation), six students sampling at the mixed marsh (referred to as site 13Y), and four students sampling at the outflow. This approach would allow an average and standard deviation to be calculated for each measured parameter at each site, and improve the reliability of combined student measurements. The design and implementation of the sampling strategy was executed so that students could achieve the learning objective to distinguish between homogeneous and heterogeneous sampling. The heterogeneity of the wetlands was reinforced as they later shared the results from each site in the wetlands and discovered differences between the sampling sites. C

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Figure 2. Total ion chromatogram showing elution of sucralose from wastewater sample at 14.4 min. Additional unidentified peaks are found throughout the chromatogram, but it was beyond the scope of this project to identify all the detected components in the complex wastewater matrix.

Figure 3. Mass spectrum for sucralose obtained in a wetlands water sample. The m/z signal 395 [M − H] was used to quantify the sucralose. The signal at 433 represents the sucralose−formate adduct.

Analytical Methods

eluted with 5 mL of methanol. The eluate, which was a dark brown color, was evaporated to dryness and then reconstituted in 1 mL of methanol. The concentration of sucralose in the extracted samples was quantified using reversed-phase liquid chromatography with mass spectrometry using an Agilent G1311B 1260 Infinity LC system with quaternary pump, vacuum degasser, and autosampler. The autosampler was used to inject 5 μL samples onto a Zorbax 15 cm reverse-phase C-18 column (3.5 μm particle size) with mobile-phase flow rate 0.25 mL/min. The mobile-phase eluents were water with 1% formic acid, and acetonitrile with 1% formic acid. The gradient method employed a starting mobile-phase composition of 90% water, 10% acetonitrile for 5 min, which changed to 10% water, 90% acetonitrile over 5 min, held for 5 min, and returned to 90% water, 10% acetonitrile over 5 min. The column then equilibrated for 5 min before the next injection. Because the samples were expected to be complex mixtures, blank samples were injected in between student samples to minimize crosscontamination. The sucralose peak retention time was 14.4 min, determined using standards with concentrations ranging from 5 to 50 ppm. An example chromatogram from extracted wastewater is shown in Figure 2.

Instructions for the routine analysis of pH, chloride, total dissolved solids (TDS), total suspended solids (TSS), and phosphate are included in the Supporting Information. Quantifying sucralose poses several challenges to an undergraduate analytical chemistry student: it does not absorb light in the visible or UV region, it is not electrochemically active, it has no acidic or basic functionality (pKa ∼ 12.5) to lend itself to titration, and it does not photoluminesce. The water matrix precludes the use of infrared spectroscopy (water interferes in the OH region), and its high boiling point (669 °C) precludes it from direct analysis by gas chromatography (it must be derivatized26 to vaporize). For this lab, a modification of the method developed by Loos et al. was employed.23 To concentrate and isolate the sucralose, the samples were subjected to solid-phase extraction with Oasis HLB solidphase extraction (SPE) columns27 (6 mL volume with 200 mg sorbent material). The cartridges were first conditioned by passing 5 mL of methanol and then 5 mL of water at a flow rate of 5 mL/min. The wastewater was filtered using a 0.45 μm filter, and then 500 mL was passed (under vacuum) through the SPE columns. The cartridges were rinsed with 5 mL of water, and then the sucralose (and other sorbed material) was D

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Table 2. Comparative Results of Tested Wastewater Analytes from the Northern Flow Train of the Wetlands Observed Analyte Concentrations by Sampling Sites Analyte

Inflow

Site 3Y

Site 13Y

Outfall

Guideline Levels or Ranges

pH TSS, ppm TDS, ppm Phosphorus, ppm Chloride, ppm Sucralose, ppm

7.30 ± 0.07 30 ± 12 246 ± 20 0.12 ± 0.03 50 ± 10 0.024 ± 0.002

7.40 ± 0.04 1.35 ± 0.07 228 ± 10 0.03 ± 0.02 37 ± 11 0.024 ± 0.004

7.53 ± 0.13 0.53 ± 0.50 238 ± 35 0.05 ± 0.04 39 ± 12 0.021 ± 0.004

7.42 ± 0.05 0.001 ± 0.005 234 ± 28 0.02 ± 0.04 31 ± 10 0.021 ± 0.009

6.5−8.5a 80b 500a 0.20c 250a 0.012−0.069d

a

These are secondary maximum contaminant level standards set by the EPA (note that pH is expressed as a secondary standard range). bThe TSS limit is reported for wastewater-treatment by Guida et al., see ref 28. cThe reference phosphorus concentration is the upper limit set by the Florida Department of Environmental Protection for phosphorus. The method reported here quantifies phosphate, not total phosphorus, but the table shows the phosphorus from the phosphate measurement for ease of comparison between reference and experimental values. dThe sucralose reference concentrations are the literature reported values from septic systems in 2011. See ref 22.

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For quantification, a literature method23 used a triple quadrupole MS−MS system; no such instrument was available for this project. The instrument used for this project was an Agilent G6230B TOF/Q-TOF mass spectrometer with dual ESI ion source, so modifications to the previously published method were necessarily made to use a single mass spectrometer. The MS utilized nitrogen nebulizer gas with 8 L/min flow at 325 °C and 35 psig. Negative ESI mode was used with capillary voltage −2900 and 175 V scan fragment voltage. A typical mass spectrum is provided in Figure 3. The method was selected and modified by the instructor (author E.C.H.). Detailed instructions were provided to the students, and when the students had prepared their samples, an instrument manager taught an informational session (∼30 min) on how the instrument worked and explained its components. The students loaded their samples into the autosampler and retrieved their chromatograms and mass spectra when their sample runs were complete. Along with each sample, five standard sucralose solutions were quantified using the same HPLC−MS method. The samples ranged in concentration (before extraction) from 0.010 to 0.10 ppm; standards were subjected to the same extraction procedure as the samples resulting in concentrations of 5−50 ppm. A linear calibration curve was produced and used for quantification of the sucralose.

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STUDENT REPORTING AND SEMINAR

Students wrote lab reports for each topic that were graded by the teaching assistant and instructor. Feedback from these reports and group sharing of all results were used to help the students prepare seminar presentation slides. Although presentations are not a typical component of this course, for the purpose of disseminating the results of the study, and to aid students in developing their communication skills, presentations were included in this project. To prepare the presentations, the students were divided into groups of three, with one group for each analyte (e.g., TSS, TDS, pH, choride, phosphorus, sucralose). One student from each group was assigned to prepare a short presentation on each of the following topics: the background and importance of the group’s analyte in wastewater (including reference or allowable ranges), the methodology used to make the measurement, and the results of the calibration and measurement. The remaining three students were each assigned to make an overall introduction to the seminar, a discussion of the sampling methodology, and a summary with conclusions, recommendations for future work, and acknowledgments. The students each met with the instructor in advance of the formal seminar and received feedback on their prepared slides with recommendations for revision. From the instructor’s perspective, these sessions were tremendously important because they revealed student misconceptions that could be corrected in advance. Some examples of student misconceptions included the following: lack of understanding about the purpose of standard addition calibration, the mechanism of the measurement for ion conductivity, and the implications of high chloride ion concentrations in natural waters. These meetings also provided opportunities to coach the students on effective presentations based on multimedia learning principles found in the literature.29 Students within groups also worked together, appearing to take pride and ownership in the overall quality of their presentation segment. The students supplied their final slides to the instructor before the final presentation, and they were assembled into one continuous presentation document. The seminar was advertised in advance to various on-campus departments, and invitations were issued to representatives of the wastewater utility, two of whom attended. Approximately 50 other faculty, students, and visitors attended the seminar. The grading rubric, which was shared with the students in advance of the seminar, is shown in the Supporting Information.

RESULTS OF CHEMICAL ANALYSIS

The results for the chemical analysis of treated wastewater from the inflow, deep marsh (site 3Y), mixed marsh (site 13Y), and outfall are shown in Table 2. Some reference concentrations for the analytes are also shown. For the regulated analytes, the concentrations are well within acceptable levels. For sucralose, it is within the range reported by Oppenheimer et al., who studied the sweetener as a potential marker of wastewater loading in surface waters.22 The gradient in the phosphorus concentration is noteworthy: its removal from the inflow to the outflow demonstrates the effectiveness of the wetlands in removing nutrients and emphasizes the need for heterogeneous sampling throughout the park. This knowledge would have been suppressed had students not worked collaboratively to share their individual data and create a complete picture of the concentration gradient. These results fulfill the learning outcome of students working collaboratively to solve a larger analytical problem through working on individual pieces that are combined. E

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Figure 4. Comparison of correct student responses between service-learning (N = 22 students) and conventional lab (N = 19 students) sections.

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ASSESSMENTS

The students were asked the extent to which they agreed with the statement “I am able to perform accurate...” with the blank filled with analytical techniques taught in the course such as spectrophotometric analysis, titrations, electrochemical analysis, and calibrations. Rather than reporting a measure of students’ actual abilities or technical skills, this item was intended to gauge the students’ self-efficacy, or belief that they were capable of completing the tasks. The Likert-type response scale from Strongly Agree (4-point value) to Strongly Disagree (0-point value) provided a quantitative way to compare the self-efficacy of the service-learning section relative to the traditional sections. In each category, the service-learning sections responded with higher self-efficacy scores (i.e., more students strongly agreed that they could accurately perform the analytical techniques). On average, the service-learning selfefficacy scores were 15 ± 5% higher in the service-learning section than in traditional sections. This difference in selfefficacy is statistically meaningful, determined by using a comparison of means t test (p = 0.005). Even if the students’ perceived skill is unrelated to their actual skill, their self-efficacy can be an important factor. Chemers et al.30 reported selfefficacy to be a predictor of future academic success in college students, and Khan31 also reports a correlation between selfefficacy and college-student GPA. All candid responses to the free comment portion of the survey from the service-learning section were positive, with two that seem noteworthy. One respondent stated, “I liked the fact that we were able to do ‘real’ chemistry. We didn’t know what to expect when we took the samples from the wetlands, and that’s what chemistry is all about. Problem solving.” Another remarked, “I’m glad I was enrolled in the section that performed the water analysis of the wetlands park. It was very interesting and helped me prepare for real world

Course-Related Skills

Student learning of chemistry content was assessed by a final exam that was administered to both the service-learning section and the conventional section. Since some of the laboratory content deviated between the two sections (specifically, redox titrations and paper chromatography laboratories were absent from the service-learning sections), there was some concern about diminished student competence in those areas. The exam was a 10-item, open-ended exam covering the Beer−Lambert Law, quantitative and qualitative distinctions, redox analysis, titration with standards (specifically KHP), dilution and concentration units, chromatography, EDTA titration, and complexation. The results are summarized in Figure 4, with error bars representing one standard deviation from the average scores on the question item. For the redox titration item, the conventional section had a larger percentage of correct responses than the service-learning section (average scores are further than one standard deviation apart). For all other items (including paper chromatography, a topic excluded from the service-learning section), the scores were either better in the service-learning section, or indistinguishable from the conventional section (as determined by comparison of means within one standard deviation). The average score on the final exam for the service-learning section was 71 ± 13%, and for the conventional section it was 67 ± 12%, indicating that there was no net content loss or understanding penalty to the students for participating in the service-learning project. Student Perceptions

Following the completion of the semester and posting grades, students completed evaluations of the course. Evaluations were approved through the university’s institutional review board. F

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applications. More labs should target industrial techniques like this to better prepare students for jobs after college.” These are noted because the students were not coached on the benefits of service-learning. Their candid responses seem to lend additional support to the previously reported benefits of servicelearning,2 with an emphasis on job skills and problem-solving.

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ASSOCIATED CONTENT

S Supporting Information *

The Supporting Information is available on the ACS Publications website at DOI: 10.1021/acs.jchemed.7b00490. Complete instructions for the water analysis (PDF, DOCX)

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LIMITATIONS AND RECOMMENDATIONS This project did not seek to provide students with methoddevelopment experiences. The students did not search the literature for methods of analysis: rather, they were supplied with protocols for quantification, as a technologist in a production laboratory might find in a standard operating procedure. Hence, no learning gains in method development were observed or reported. From a service standpoint, the objective of the project was to provide a public utility the information they sought regarding sucralose: if sucralose could be detected in the water and, if so, how its concentration changes throughout the flow train from influent to outfall. In future, the data acquired here may be supplemented with a longer-term study to examine the fluctuations in sucralose concentrations with sampling over a longer time frame. Collaboration with OEW continues and is evolving to meet the needs of the public partner. Currently, method development is underway to quantify other analytes of interest to the OEW personnel. Other instructors may be able to implement some or all of this activity on their own. For this project, the collaboration with the public utility began by reaching out to the manager at the wetlands, with no prior connection or introduction. The authors recommend contacting a local water-treatment utility to assess potential for collaboration, and inquiring whether chemical analysis of their water would be useful and, if so, what analysis would align with their interests. Even if wastewater is not available, agricultural or urban runoff may be used for analysis of pH, phosphate, or total dissolved solids.

AUTHOR INFORMATION

Corresponding Author

*E-mail: [email protected]. ORCID

Emily C. Heider: 0000-0002-9728-6863 Notes

The authors declare no competing financial interest.

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ACKNOWLEDGMENTS We gratefully acknowledge the collaboration of Rachel Kessler and Mark D. Sees at the Public Works Department, Division of Wastewater, City of Orlando. This work was supported in part by the National Science Foundation under CHE-1455159.

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REFERENCES

(1) Boyer, E. The Scholarship of Engagement. J. Public Serv Outreach. 1996, 1 (1), 11−20. (2) Eyler, J. Reflection: Linking Service and Learning - Linking Students and Communities. J. Soc. Issues. 2002, 58 (3), 517−534. (3) Melton, L. The Doctor of Chemistry Program Career Preparation for Industrial Chemists. J. Chem. Educ. 1991, 68, 142−144. (4) Levy, F.; Cannon, C. The Bloomberg Job Skills Report 2016. https://www.bloomberg.com/graphics/2016-job-skills-report/ (accessed Nov 2017). (5) Cartwright, A. Science Service-Learning. J. Chem. Educ. 2010, 87 (10), 1009−1010. (6) Hatcher-Skeers, M.; Aragon, E. Combining Active Learning with Service Learning: A Student-Driven Demonstration Project. J. Chem. Educ. 2002, 79 (4), 462−464. (7) Glover, S. R.; Sewry, J. D.; Bromley, C. L.; Davies-Coleman, M. T.; Hlengwa, A. The Implementation of a Service-Learning Component in an Organic Chemistry Laboratory Course. J. Chem. Educ. 2013, 90, 578−583. (8) Esson, J. M.; Stevens-Truss, R.; Thomas, A. Service-Learning in Introductory Chemistry: Supplementing Chemistry Curriculum in Elementary Schools. J. Chem. Educ. 2005, 82 (8), 1168−1172. (9) Kalivas, J. H. A Service-Learning Project Based on a Research Supportive Curriculum Format in the General Chemistry Laboratory. J. Chem. Educ. 2008, 85 (10), 1410−1415. (10) Kesner, L.; Eyring, E. M. Service-Learning General Chemistry: Lead Paint Analysis. J. Chem. Educ. 1999, 76 (7), 920−922. (11) O’Hara, P.; Sanborn, J. A.; Howard, M. Pesticides in Drinking Water: Project-Based Learning within the Introductory Chemistry Curriculum. J. Chem. Educ. 1999, 76 (12), 1673−1677. (12) Draper, A. J. Integrating Project-Based Service-Learning into an Advanced Environmental Chemistry Course. J. Chem. Educ. 2004, 81 (2), 221−224. (13) Tal, R. T. Using a Field Trip To a Wetland as a Guide for Conceptual Understanding in Environmental Education - a Case Study of a Pre-Service Teacher’s Research. Chem. Educ. Res. Pract. 2004, 5 (2), 127−142. (14) Black, C.; Wise, W. Evaluation of Past and Potential Phosphorus Uptake at the Orlando Easterly Wetland. Ecol Eng. 2003, 21, 277−290. (15) White, J. R.; Gardner, L. M.; Sees, M.; Corstanje, R. The ShortTerm Effects of Prescribed Burning on Biomass Removal and the Release of Nitrogen and Phosphorus in a Treatment Wetland. J. Environ. Qual. 2008, 37, 2386−2391.

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CONCLUSION The service-learning project reported here was intended to provide students the opportunity to apply their analytical skills to relevant and real problems, learn new analytical techniques, and develop professional communication skills. The design and implementation of a wetlands wastewater analysis project, and the task of reporting it in a public seminar, met these objectives. For this study, including such an activity has not come at a cost of content knowledge or compromise in the curriculum. Rather, it has expanded the students’ technical repertoire to include field sampling, solid-phase extraction, and HPLC-MS. Additionally, service-learning students report higher self-efficacy than those in traditional sections. Over the past decade, leaders in both industry and academia have been calling for additions to the chemistry curricula in support of improving job skills of college students, with communication skills,3 a willingness to volunteer, and “a reflective and aware attitude”32 among the highest in demand. Participation in service-learning can provide chemistry students the opportunity to develop those skills and better prepare them for the workforce. Since completing the sucralose servicelearning project, other community organizations have sought assistance from this university for quantifying sucralose and monitoring water-quality, providing additional opportunities to engage students in outreach. G

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Journal of Chemical Education

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DOI: 10.1021/acs.jchemed.7b00490 J. Chem. Educ. XXXX, XXX, XXX−XXX