K-5 Thin-Layer Chromatography: Three-Dimensional Analysis of Pigments from Plant Materials Using an Interlocking Building-Block Photography Box

• Melissa Saldaña ^[2] ; Stephanie A. Valenzuela ^[1] ; Sarah R. Moor ^[1] ; Pedro Metola ^[1] ; Eric V. Anslyn ^[1]
  1. [1] University of Texas at Austin

     University of Texas at Austin

     Estados Unidos

     
  2. [2] Claude Berkman Elementary School, United States
• Localización: Journal of chemical education, ISSN 0021-9584, Vol. 97, Nº 12, 2020, págs. 4414-4419
• Idioma: inglés
• Texto completo no disponible (Saber más ...)
• Resumen

  • It is widely understood that students are able to learn and comprehend topics better as active participants. Topics related to science, technology, engineering, and mathematics are often mistakenly considered too difficult for elementary students to grasp. Conducting simple hands-on science experiments can be a useful instructional approach, allowing young scholars the ability to better grasp key scientific principles. We felt chromatography would make an ideal technique to incorporate into the elementary school curricula due to its ubiquitous use throughout the field of chemistry. We have designed an activity that combines chromatography with pigments extracted from plant materials to create a new, interactive activity that allows students to take on the role of a scientist. Students extract pigments such as chlorophyll, anthocyanins, flavonoids, and carotenes from plant materials, and separate the pigments using thin layer chromatography. The students construct a photography box from interlocking building-blocks and build a circuit that is used as a light source for the box. The developed thin layer chromatography paper is placed inside the box, and using a smartphone, a photograph is taken for analysis. Using a python script developed for this activity, students are able to analyze the photograph of the thin layer chromatography paper in a three-dimensional space that determines the red, green, and blue values, and the hue and saturation values of the pigments. This activity allows students to actively learn important scientific principles such as chromatography, color theory, and circuitry, all while working with common household items and toys, such as interlocking building-blocks, and smartphones, for instrument construction and analysis.