Arsenic Lab Understanding how arsenic in water can affect our food


The purpose of our 11th grade Chemistry arsenic research expedition is to show students what university-level research is and to give them the chance to take part in an ongoing study aimed at helping solve a real-world problem: arsenic contamination in rice. Students meet Dr. Julian Tyson, professor emeritus of Analytical Chemistry at UMass and learn about his research into arsenic detection methods. Most years we focus on developing reliable methods for detecting arsenic in rice, but sometimes we work on improving test kits for use detecting arsenic in water. Since our students’ work is meant to contribute to the work of Dr. Tyson’s graduate and undergraduate students, 11th graders are asked to present their experiments and findings in a specific professional format: the research article. The audience for their work is Dr. Tyson and the student researchers in his lab, as well as our own future Chemistry students, who will need high-quality models.

After building background knowledge using a variety of protocols to introduce the issue of arsenic students are asked to get familiar with the format of a research article using close reading protocols geared toward complex texts. Their teacher introduces the test kits, reagents, and reactions they will use to conduct the majority of their experiments. Students are put into groups and select research topics that Dr. Tyson has provided. Each year the topics are different, as they reflect the current state of his research. One of the biggest sources of motivation for the students is that even Dr. Tyson doesn't know what the Four Rivers students’ research will find - there are no answer keys and they themselves are generating new knowledge. They are also building skills in scientific research and experimentation.

Their teacher tracks individual student progress on several skills related to the expedition.

Students design an experiment plan that they will present to Dr. Tyson when he visits the chemistry class. Dr. Tyson, very much the “research boss,” helps students get a sense of the pace and workload needed to produce a quality product while they engage in a type of work that is new to nearly all of them. As the experiments are being conducted, students look again at the examples and models of research articles, created by the previous years’ Chemistry students and by professionals in the field. They think about how their work and their documentation will fit into the end product of a research article. Once the experiments are done the students take a divide-and-conquer approach to the different sections of the article. Once the group has put together a rough draft with all the appropriate sections, they decide on one member to be the final editor who will use more of teacher feedback to put the finishing touches on the article and get ready to share it with Dr. Tyson.

Over the last three years of this expedition, student work has improved in both the content and the writing of the articles. The first years’ reports looked more like the lab reports they had been asked to write in science classes. They were missing stylistic elements that help define the writing style of analytical chemistry articles. For example, the procedure was not written in passive voice, there were bullet point listings of materials, and the unit parts per billion was used instead of the preferred micrograms per liter. The content of the articles was above the level of traditional lab reports, but still left out some information that would allow another researcher to repeat their experiments. Dr. Tyson described these reports as consistent with what most first or second year undergraduate researchers would produce.

The second year’s articles had better adherence to the style of this type of article, but the students struggled to properly connect their results with the greater research effort. There were still some tables with incorrect formatting, mislabeled units, and other stylistic errors, but the articles in general looked more like the kind of article that Dr. Tyson or other researchers would produce. The data that students produced was rather nuanced, however, and they focused more on the shortcomings of the reaction on which their work was based rather than on what the results told us that is new. This meant that their articles added less to the overall understanding of the reaction than they otherwise would have. Still, Dr, Tyson reported that the second year’s articles looked more like 3rd year undergraduate work, an improvement over the previous year’s writing.

This year saw an improvement in both the style and the content of the reports. Groups are more consistently spotting style errors and changing their work to reflect the guidelines of analytical chemistry papers. There was a noticeable increase in the accuracy and level of detail in their writing. They generated data that was able to show clear relationships and suggest new ways forward for future studies of these reactions, and their analysis reflected more complexity and understanding of the concepts they were studying. There is still plenty of improvement possible in terms of experimental design and execution, as well as documentation, however. Dr. Tyson will review these papers once they are completed later this spring and he and the Four Rivers Chemistry teacher will talk about them in the summer or early fall, and be ready for next year's arsenic work with students

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