CHM120H5 Lecture Notes - Lecture 1: Natural Abundance, M163 Vads, Bromine

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champagnesnake906

19 Apr 2015

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Mass spectrometry is a technique in which an instrument known as mass spectrometer, designed by j. j. thompson in 1911, at cambridge, is used to confirm or identify chemical species. The data obtained from this experiment is called mass spectrum, which in general is a plot of the relative number of ions of relative intensity versus the mass/charge ratio (m/q). In this experiment, a data obtained from similar kind of instrument was used to identify an unknown chemical species. The purpose of the experiment was to understand the working of the mass spectrometer and to get familiarized with the analysis of mass spectrum to obtain the identity of the unknown chemical species. The procedure associated with this experiment was fairly simple and basically dealt with the analysis of the mass spectrum. The experiment started with the identification of the molecular ion peak, m+2 isotope peak and m+1 peak, which were then considered on the basis of the nitrogen rule".

Related Questions

Chemistry Help: Very Bottom of Page are the questions and thedata is above the Data Analysis Questions #1 #2 #3 #4 ? Help pleaseshow work so I could understand how you solved the questions.

Good Afternoon,

I am doing a laboratory report for the course entitled: Principles of Instrumental Analysis. It is a 4th year course and i have been tasked with the following analytical problem, "Determine the DEET composition in common bug sprays." In other words, I have to determine the concentration of DEET in a couple of bug sprays. The sprays and DEET are supplied. Secondly, I have to prepare a protocol for measuring the concentration of DEET in my samples and a GC:MS method for analysis of DEET. By the way, GC:MS is short for 'Gas chromatographyâmass spectrometry' and as you may know it is an analytical method that combines the features of gas-chromatography and mass spectrometry to identify different substances within a test sample. Basically, I need your help in giving me a layed-out protocol (such as we would see in a manual) of what I will do in the lab to answer the above analytical problem. You can think of it as a lab manual that you would write so that someone else could go in the lab and perform the experiment in your place.

It should have all of these components.

1. Brief (!) introduction of the problem (1 short paragraph)

2. Sampling â how much (be precise), in what form, how many, where, etc.

3. Sample preparation â list all reagents needed up front. Then list all steps and procedures you will use to prepare the samples for instrumental analysis. You should know what concentration ranges you are aiming for.

4. Standards preparation â list steps involved in preparing your standards used for calibration (if you need to do this).

5. Instrumental Analysis â list the procedure for running the instrument, including any blanks, standards. The sequence of runs (sample, standard, blank, etc) should be listed.

6. Data Analysis â how will you go from the raw data provided by the instrument to a value with a Â± deviation on it.

Please refer to the above question. Can you give me a detailed layout of how I will determine the concentration of DEET in my samples before doing the GC:MS analysis? You do not need to determine the composition or synthesize DEET. You need to determine the concentration of DEET, in a couple of bug sprays. The sprays and DEET are supplied.

I'm not quite understanding. Thank you for your clarification once again.

Identification of an unknown compound

Needed:

Draw the actual structure of the unknown

Explain why this conclusion was reached

Explain how the functional groups were determined based IR

How did you get the exact structure from using NMR

Identify how chemical shifts and peaks areas match hydrogens in the proposed structure

Comment on splitting patterns if they are discernible

Determine the identity of the unknown, explaining why the structure is consistent with NMR and IR

Include melting/boiling points, compare with the literature value of your unknown

Include the reflective index