Fitting It All In: Adapting a Green Chemistry Extraction Experiment for Inclusion in an Undergraduate Analytical Laboratory

Abstract

Several principles of green chemistry are introduced through this experiment designed for use in the undergraduate analytical chemistry laboratory. An established experiment of liquid CO2 extraction of d-limonene has been adapted to include a quantitative analysis by gas chromatography. This facilitates drop-in incorporation of an exciting experiment into an existing curriculum. The experiment provides an introduction to natural product extraction, calibration curves, and internal standards while simultaneously demonstrating alternative solvent selection for pollution prevention and increased chemical safety.

Isolation of biologically active compounds from mangrove sediments

“…Many previously published laboratory experiments pertaining to the subject include one or more standard steps: extraction of the NPs from crude material, separation and analysis using various chromatographic techniques, identification and characterization of the isolated compounds, and determination of their biological activity. Similar to work presented here, extraction procedures involved the utilization of various organic solvents [28][29][30]. The range of chromatographic techniques varied from simple paper chromatography [31] and TLC [30,[32][33][34], with the latter noting, "the students recognize that TLC does not have the resolving power necessary to separate the extracted compounds and are guided towards a more powerful alternative, HPLC" [35].…”

“…HPLC is widely used in undergraduate teaching environments [35][36][37][38], so the utilization of HPLC in this paper is an obvious choice given the complexity of the extract. For characterization of compounds, gas chromatography, sometimes coupled to a mass spectrometer (GC-MS), has been utilized [29,39,40] and in some cases, high-resolution mass spectrometry has also been used [39]. Most of the papers referenced above used the standard analytic methods of molecular characterization using NMR spectroscopy, optical spectroscopy, and mass spectrometry.…”

Extraction of dyes contained in glow sticks using liquid CO2

“…Both liquid CO 2 and supercritical CO 2 can be used as a substitute for volatile organic solvents in extraction and chromatographic methods (1)(2)(3)(4)(5)(6)(7). CO 2 can be obtained from and returned to the air in a cyclic fashion, it is neither toxic nor flammable, and its use as a solvent avoids the production of large quantities of waste solvent (7).…”

“…Indeed, several experiments that involve the use of liquid CO 2 during extractions and chromatographic separations have appeared in the chemical education literature. For example, the use of liquid CO 2 to extract various organic compounds from orange peels (1,2), fennel seeds (3), cloves (4), and essential oils (5) has been previously reported.…”

Extração Do R-(+)-Limoneno a Partir Das Cascas De Laranja: Avaliação E Otimização Da Verdura Dos Processos De Extração Tradicionais

“…(-)-carvona 38 e α-terpineol 39 ), que o usam como reagente estequiométrico; bem como, no contexto da QV, isolamento do limoneno utilizando dióxido de carbono líquido como solvente, para ser utilizado no laboratório de química analíti-ca. 40 Por outro lado, na revista Green Chemistry foram publicadas propostas de novos procedimentos de extração do óleo de laranja: o uso de líquidos iónicos como solventes de extração; 11 a utilização de solventes mais benignos na extração, como o dióxido de carbono líquido, 41 óleo alimentar e polímeros (polietilenoglicol e polipropilenoglicol); 42 e o uso de processos hidrotérmicos com micro-ondas de baixa temperatura. 7 Estes estudos mostram preocupação em obter processos mais verdes para a extração do óleo de laranja, 11,[40][41][42] mas não incluem qualquer referência à importância da avaliação e análise da verdura dos processos tradicionais e alternativos.…”