Environmental issues, laboratory experiments

High school students should have a greater understanding of global environmental issues. This can be accomplished by using environmentally-relevant examples to teach high school chemistry. Appropriate demonstrations and laboratory experiments that illustrate these topics are suggested. To incorporate additional environmental chemistry in die secondary curriculum, help from environmental scientists will be needed. 

Welch et al. evaluated analytical procedures and environmental issues. They investigated methods for the extraction and detection of cocaine, some of its metabolites, morphine, and codeine from hair. They concluded from a round-robin study that extractions with 0.1 ATHCL are as efficient to remove the target compounds from hair as enzymatic digestion that dissolve the hair. GC/MS with either El or Cl provides accurate determinations of the targeted compounds. External contamination by powdered or vapor-deposited cocaine was incompletely removed by all approaches tested, making it difficult to differentiate incorporated drug from external contamination. This was also proved in extensive laboratory experiments by Wang and Cone. ... 

The cornerstone of a sound program for prudent laboratory practices is a process designed to comprehensively review the operations and potential hazards associated with each experiment over its life cycle. This review should take place before any work is conducted. The diverse nature of research and development activities makes it advisable to have such a process in place as part of the scientific method of experimentation. In laboratories where this preliminary survey is routinely practiced, it has proved to be useful in both the maintenance of safe laboratory operations and the minimization of chemical exposure and waste generation. Because of the diversity of types of researchers and laboratory work, such processes— both formal and informal—can help individuals associated with new, modified, or unfamiliar experiments or procedures to plan and work safely, responsibly, and productively. By first evaluating the work area, materials, equipment, and procedures in depth, hidden hazards may be identified and addressed. The pre-experiment review process can also help to ensure that every experiment and laboratory operation complies with all applicable laws, regulations, and other policies. Moreover, by addressing all relevant health, safety, and environmental issues when an experiment is first conceived, further research, scale-up, or development based on it can be made safer and more effective. 

Mandler, D. Blonder, R. Yayon, M. Mamlok-Naaman, R. Hofstein, A. Developing and Implementing Inqu A. Developing and Implementing Inquiry-Based, Water Quality Laboratory Experiments for High School Students to Explore Real Environmental Issues Using Analytical Chemistry. 

The fundamental issue is to describe how much of the residue can be characterized accurately and whether an accounting of the applied mass of pesticide can be maintained throughout the course of the experiment. A series of environmental fate studies is required for pesticide registration in order to characterize the degradation pathways and formation and decline patterns of each major degradate. These studies are typically conducted in the laboratory under controlled conditions, applying radiolabeled pesticides to evaluate the extraction efficiency of various procedures. When standard extraction methods fail to release a significant amount of the applied radioactivity, more efficient and exhaustive extraction procedures are tried in a stepwise fashion... 

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