how errors in analytical procedures are identified | My Assignment Tutor

1,000 words, excluding references. ONLY ONE EXAMPLE The coursework title is in your handbook: ‘Discuss the processes used to identify how errors in analytical procedures are identified. Use one example to help explain the relevant processes’. You can select any relevant two examples, but it is very strongly suggested that you use two of your own practical reports as examples. These can be first or second year practicals you have done / written a report for. Essentially you are reviewing / commenting on your own personal work, which will enhance your professional development and self-reflection skills. Please bear in mind that you must NOT use one of the examples provided in the presentation. When you write up a practical report, you often give a brief introduction, list or describe the materials and methods (sometimes explaining a little about the theory), give your results in tables and sometimes graphs and drawing the attention of the reader to what those results might mean. Then follows a discussion section, which explains the results and finally your conclusions. In addition, you are often asked to explain potential sources of errors. This coursework is intended to take things a step further, and encourage you to act as an objective ‘investigator’ of the experiment(s), consider the outcomes, and explain where errors happened or could happen and also explain how you might improve the experiment outcomes for the future. The focus is on your own analysis / investigation of your own experiments and how you would improve the outcomes, if you had to repeat the experiments to a high level of quality. A detailed explanation of ‘six sigma’ is NOT needed, nor do you need images / diagrams from the internet. Your submitted work should give a concise introduction, explaining the importance of quality assurance in science then focus on your own analysis / investigation of your examples. You may want to include a table or graph from one or both of your experiments to illustrate what you are discussing / explaining. Just to get you started, here are a few ideas to think about:  If you were using a pipette, did you calibrate this? Did you use the same pipette or ‘swap’ it with someone else’s half way through making your dilutions? Not all pipettes will deliver exactly the same volume, even if they are set to the same value (eg 50 microlitres). Did you use the pipette at the same angle? Using a pipette at different angles can often result in different volumes being delivered. It won’t change much, but it might be enough to alter your eventual readings (eg in a spectrophotometer).  Did you do your experiment in duplicate (do you think triplicate would be better)? Why would you want to do that?  Can you be sure any glassware was uncontaminated?  Can you be sure that chemicals used were ‘in date’? Just like food products, chemicals have ‘expiry dates’. This is especially true for labile substances such as enzymes.  What about temperature? Was this important in your experiment? Did you check and record the temperatures at which you did your experiment? This is also important if you are doing enzyme work – enzymes degrade if they get ‘warmed up’. Did you keep samples on ice, if that was suggested? Or did you leave the bottle lying around on the bench while you were working?  Did you make sure to zero your spectrophotometer? And did you give the machine enough time to ‘warm up’. They drift over time – the reading is sometimes not completely constant. So did you check your zero frequently?  Did you get your ‘dilutions’ right? Did you make sure you double-checked your calculations?  Did you record your results carefully, with the relevant units noted? Could you have made an error when you recorded them? Did you ask a colleague to check that you had written the result down correctly?  Did you recheck your result / procedure if you got an unusual result (eg a very high or low reading)?  Did you follow the SOP (standard operating procedure) / practical schedule / worksheet correctly? Bear in mind that the SOP may sometimes have an error in there – if you found one, did you check this with the supervisor?  When drawing any graph did you get the units / axes right? Ideally you should do a rough graph in the lab, as a quick way of checking that your experiment is working as expected.  Did you read you schedule in advance, so that you could be confident of working effectively, and identify any potential difficult procedures? This is a good way of reducing the possibility of error.  You might want to comment on how ‘serious’ certain errors might be for your outcome. If you used contaminated glassware or pipette tips, for example, that might have a serious impact on your results. If you used your pipette at 90 degree for some of your dilutions and 45 degrees for others, that would probably have little impact, so would be a less serious impact on the outcome. If your experiments went wrong, and you didn’t have a good outcome, this will not be penalised in the context of this assessment. For this coursework, the objective is for you to see where things went wrong, and how you might improve things for the future. It is also about making some kind of self-evaluation and judgement on your own work, which in itself is an important skill.


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