Chem 4101 – Fall 2011 September, 2011 !1 Defining and solving problems with analytical methods 1. Many situations and incidents in daily life, the news, industry, a clinical setting, a research environment, etc. require investigation based on analytical chemistry methodologies. In this course, we refer to these situations as analytical chemistry problems. Central to this course is learning on how to define analytical chemistry problems and proposing the use of analytical methodologies to investigate such problmes. Some examples of problems investigated in previous years are found below. 2. Define an analytical chemistry problem. The first step will consist in identifying a situation or incident that requires analytical chemistry to be solved. The problem must be original but it can be based on articles found in newspapers, scientific magazines, on-line resources, etc. State clearly the relevant background, the importance of solving the problem and what will be gained if the problem is solved. In order to begin solving the problem, define an initial hypothesis (possible explanation for what has occurred or is behind the situation under observation). [Evaluated in a Quiz the second week of classes. The instructor and the TA can provide feedback on ideas that you may have prior to the Quiz] 3. Expand your background on the problem. Using past issues of Chemical and Engineering News (or other library resources) define the a situation or incident that needs to be investigated with analytical chemistry methods. Exclusive use of on-line resources such as google searches or wikipedia is not sufficient. [There will be a session on how to use the Library Resources at the UMN to help you fine tune your literature search skills]. 4. As each analytical chemistry technique covered in this course is discussed in class, evaluate its use to investigate your analytical chemistry problem. This requires a new literature search for each technique. For each technique you will need to consider the characteristics of the analytical method (i.e. figures of merit), nature of the sample, and the characteristics of the instrument. See below. Characteristics of Analytical Method a. Limit of detection. b. Limit of quantitation. c. Linear dynamic range. d. Precision. e. Accuracy. f. Sensitivity and S/N. g. Selectivity towards the species of interest. h. Major interferences. i. Resolution. j. Sample preparation and stability. k. Robustness. l. Speed-throughput. m. Material and Reagent Safety. n. Cost/assay. Characteristics of Instrument a. Access.Chem 4101 – Fall 2011 September, 2011 !2 b. Operation parameters. c. Speed. d. Size and portability. e. Destructive/nondestructive. [Quizzes, postings in the blog, and exams will be assess the utility of each technique for investigating your own analytical problem] 5. Present a poster describing your analytical problem {Poster/Oral Exam scheduled for December 2011}. A poster is a visual display of information and appropriate leading text. The same information could also be presented orally with slides. The chief virtue of a poster presentation is that it encourages strong verbal interaction between the author (you) and the audience (other class members and, in this case, evaluators). Examples of posters prepared in previous years and hints on how to prepare postesrs are available in the course blog. 6. What is the Topic of the poster? The topic will be your proposed solution to your analytical chemistry problem. The poster will incorporate the definition of the problem and various hypotheses that were explored throughout the semester. It must articulate the logic and critical thinking involved in selection of appropriate analytical methodology for investigating the problem, and includes a comparison to alternative approaches. Your poster will also include among other important points the specifications of the methodology, the physical and chemical principles underlying how the methodology works, and your logic as to the choice of the solution including choice of a specific make and model of instrument. General guidelines on how to prepare and present a poster are given in (Huddle, 2000) and (Block,1996), respectively (access these papers through links in the blog). Examples of posters prepared in previous offerings of this course will be posted in the blog. These examples will be critiqued in class so that you take some ideas on how to assemble your own poster. 7. What will be included in your Poster? In a maximum of 12 panels (8.5” x 11” each) include: a. Poster title, your name, course, date. b. Definition of the problem, including a central hypothesis. c. Importance and significance of solving the problem. d. Summary of the relevant analytical techniques that were reviewed in the course, with a rationale for selecting those techniques that are more promising to carry out the proposed measurements. e. A diagram explaining the fundamental principles of the chosen technique(s). f. Description of the instrumentation chosen. Provide a rationale for the selection of such an instrument over other models/makes. Include instrumental parameters that will be used to analyze samples. Include analytical specifications (LOD, LOQ, precision, accuracy, selectivity, resolution, etc.) and demonstrate that they meet the need. g. Experimental design including sample preparation, use of controls, replicates, etc. Proposed data analysis and interpretation. Include examples of possible results taken from the literature. h. Conclusions. i. References.Chem 4101 – Fall 2011 September, 2011 !3 Examples of analytical problems (Do not select any of these topics for your own problem) A simple laxative solution (magnesium citrate in water) is found to have a solid, crystalline precipitate in the bottom of the bottle. What is this material, how did it form, and how its formation be avoided? In the movie "Erin Brockovic" the plot centers on the consequences of local residents suffering from illnesses attributed to the irresponsible handing of hexavalent chromium used in a PG&E compressing facility. How would you confirm that water from the compressing facility is responsible for the illness? Detecting explosives that may be used by terrorists (C4 and related nitrotriazines) is critical to homeland security. How would you proceed to develop an analytical instrument to detect explosives, perhaps from a fingerprint of a
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