Analysis of Vanillin in Maple Sap for the High School Laboratory
The goal of this research was to adapt a reversed-phase HPLC method and develop associated classroom materials for the analysis of vanillin in maple sap for high school laboratories. The analysis of maple sap has broad applications in assessing tree health and addresses different content areas including: chemistry, biology, environmental science and mathematics. The students use HPLC instruments that are made available for loan to high schools throughout New Hampshire by the University of New Hampshire’s Joan and James Leitzel Center for Mathematics, Science and Engineering Education. Previous work by researchers in our group have analyzed maple sap to determine seasonal trends in phenolic compounds, including vanillin, as a possible indicator of tree stress by employing HPLC gradient elution conditions that utilize chemicals that are not compatible in a high school laboratory setting.1,2 The modified method utilizes isocratic mobile phase conditions consisting of very dilute isopropyl alcohol and acetic acid to separate vanillin in maple sap within the time constraints imposed by the high school schedule. Sample preparation and processing are simple and limited to filtering the sap samples prior to injection into the instrument. Classroom materials were created to include safety protocol, lesson plans, and an operation manual. Each were designed to incorporate the principles found in the Next Generation Science Standards (NGSS), the K-12 Science Literacy New Hampshire Curriculum Framework and other national education standards. This method and classroom materials were piloted at three local high schools. An IRB approved survey was distributed at School B and School C. Student responses were examined to determine how well students understood HPLC and how effective was its use in the high school laboratory.