The maple sugar industry in the United States represents a significant contributor to the economic potential for agricultural operations in the northeast portion of our country. In addition, the maple industry is historically and culturally important to the area; yet, surprisingly few students understand the basic physical processes involved in maple syrup and sugar production. Recently, the maple sugar industry has become increasingly concerned with issues of product purity with regard to the presence of trace elements due to potential air bore and ground water contamination. It is the goal of this project to introduce high school students to the processes involved in maple sap collection, syrup and sugar production and analysis of samples for trace element contamination by way of Neutron Activation Analysis (NAA) at the Penn State research reactor facility.

As part of the chemistry curriculum at State High, we discuss various aspects of aqueous solutions, including concentration and its effect on colligative properties such as melting and boiling points. An ongoing theme in this class has been aqueous solutions of sugars, such as sucrose, and the physical properties of these solutions. For example, one project involved the preparation of a super-saturated solution of sugar and the formation of rock candy. As part of our ongoing collaboration between the science and agricultural programs here at State High, we have begun tapping a number of maple trees on our campus and have been boiling the sap to produce maple syrup. A question that was posed by some students concerned the purity of the syrup and how it compared with the purity of commercially available samples. Specifically, since our campus is in an urban setting, are there issues of trace heavy metal contamination?

The proposed project involves four basics aspects: (1) Initially, students will learn about maple syrup production. This will be accomplished by having two sections of the Chemistry 1 class (40-50 students) conduct a laboratory experiment in which they collect maple sap in the spring of the 2007-08 school year, boil the sap to remove excess water, and monitor the boiling point and color changes of the solution during the process. (2) Students will take a field trip to PSU’s Shavers Creek Nature Center, where they will participate in the Maple Harvest Festival. This will facilitate learning more about commercial maple sugar operations. (3) Samples of sap and syrup will be collected by students and prepared for trace element analysis by NAA. As part of this process, students will take a field trip to the PSU research nuclear reactor and learn about neutron activation. Samples will be irradiated and data collected by support personnel at the reactor facility. During the summer of 2007, the principle investigator will be engage in professional development activities and be trained to participate in the neutron activation studies. This will facilitate his communication of the details of this process to his students. (4) The final aspect of the project will involve communication of the results by having students present a paper or poster at a scientific meeting or symposium, such as the Pennsylvania Junior Science and Humanities Research Symposium, which is held annually at the Penn State University conference center.

This project will help support a number of units in our chemistry curriculum, such as solution chemistry and nuclear chemistry. In addition, a number of state standards will be addressed. As specifically stated in the descriptor for section 3.4 Physical Science, Chemistry and Physics, “Physics and chemistry involve the study of objects and their properties. Students examine changes to materials during mixing, freezing, heating and dissolving and then learn how to observe and measure results. In chemistry, students study the relationship between matter, atomic structure and its activity. Laboratory investigations of the properties of substances and their changes through a range of chemical interactions provide a basis for students to understand atomic theory and a variety of reaction types and their applications in business, agriculture and medicine.”

1 BHANDARI S. A.; AMARASIRIWARDENA D.; “Closed-vessel microwave acid digestion of commercial maple syrup for the determination of lead and seven other trace elements by inductively coupled plasma-mass spectrometry” Microchemical Journal, 2000, vol. 64, no1, pp. 73-84.

2 WATMOUGH Shaun A. “A dendrochemical survey of sugar maple (Acer saccharum Marsh) in south-central Ontario, Canada” Water, Air and Soil Pollution, 2002, vol. 136, no1-4, pp. 165-187.

For more information concerning the equipment used to make maple syrup for our project please visit http://www.maplemadness.com/backyard.html