Extraction of dyes contained in glow sticks using liquid CO2

The authors report this easy-to-follow procedure for separating glow stick dyes from a cotton swab using liquid CO2 to illustrates several key chemical concepts, such as polarity, reaction rates, chemiluminescence, and the benefits of CO2 as a green solvent. This procedure is suitable for a diverse range of students. Due to the varying polarities of the dyes, some are preferentially dissolved in the liquid CO2, while others remain attached to the cotton swab. Both TCPO (bis(2,4,6-trichlorophenyl)oxalate) and H2O2, which are crucial for producing chemiluminescence, are found in the extracted liquid and on the cotton swab. This allows for a comparison of the emission spectrum between the extracted fluid and the original glow stick, often highlighting the absence of certain emission peaks associated with polar dyes in the extracts.

Full citation
Baldwin, B. W., Bunker, K. R., & Kuntzleman, T. S. (2019). Extraction of dyes contained in glow sticks using liquid CO2. Green Chemistry Letters and Reviews, 12(2), 102-106. https://doi.org/10.1080/17518253.2019.1609594