Chem 443
Lab II
Fall 2015
This lab can be started only after the completion and submission of the report for Lab 1 and after the selection
of the topic of interest. Prior to the lab students need to work with the instructor to ensure that relevant
chemicals as well as appropriate equipment are available.
Motivation
In real life any chemist or scientist may face a situation where they need to determine a specific analyte in a
particular matrix. They will need to select a method based on the literature review (as performed in the 1st
assignment) and then test the method. The goal of this lab is to prepare students for such a situation.
Topic Selection
The topic of the second lab will depend on the student’s selection of analytes (which may be the same as those
targeted in the 1st assignment). Other options for the topic selection are a selection 1) a new topic or 2) a topic
from those offered within this manual. It is essential that the equipment to perform experiments must be
available - students need to verify this with the instructor.
The selections should be performed by 5th week of the course, the students need to support their selection by a
peer reviewed paper(s) which they are planning to use as a main resource.
They also need to verify that essential chemicals are available at the department by checking on the Chemistry
server, Abbott 911, where they also need to acquire a copy of a material safety data sheet to be used in the case
of emergency. If needed, they may have to prepare a purchase order for essential standards.
By the 8th week, students need to meet with the instructor to schedule the actual lab/equipment availability and
discuss the exact protocols to be pursued
Equipment Available
Sample preparation
Analysis
Sonication
GC-MS with a column with 5% phenyl dimethylpolysiloxane
stationary phase (use of other columns has to be negotiated)
Soxhlet
LC-UV, check for column availability
PFE
LC-UV-TOFMS, check for column availability
SPME
Ion chromatography analyzer, check for column availability
Ultrasound
GC-FID
Task
Students are expected to determine the analytes in the matrix of interest and validate the method with a
verification of their procedure. This work can be done in teams of two students, however the final report must
be individual and it must clearly demonstrate independent work.
For this, the student needs to perform:
a)
b)
c)
d)
e)
f)
Literature search and propose the most suitable method for both sample preparation and analysis
Prepare a sample using the proposed method (preferably in triplicate)
Prepare the pertinent calibration standard
Analyze samples and standards
Written report
Oral presentation
1
Chem 443
Lab II
Fall 2015
Literature Review
This task should be performed in the same manner as described in Assignment 1. If the same topic is selected,
students can use the material from Task 1.
Sample Preparation and Analysis
Prior to conducting the work, students need to confirm with the instructor the experimental approach to be
used and schedule the work to ensure availability of the equipment, chemicals, and essential training.
Each student should perform his/her own sample preparation (i.e., students will prepare two sets of triplicate
experiments). As a team, students may decide to compare two different sample preparation methods, each
preparing his/her sample via a different method.
Calibration standard should be prepared in a similar manner as for lab 1. However, students need to consider
the suitability of the solvent used earlier for the new task.
The analysis will be performed under supervision of the instructor or graduate students operating specific
instruments.
Written Report
The lab report will be evaluated on the basis of (1) the initial preparation for the lab (5 pt) (2) ability to deal with
the laboratory tasks (10 points); (3) a written report (in an electronic form) (40 points), consisting of the written
and spreadsheet sections (20 points each).
The report should include a title page with the date the experiments were performed, and names of the
students performing experiments. The report should be written in a manner similar to the articles published in
peer reviewed journals including formatting (see, for example, J. Chromatography guidelines for authors and/or
some article). Thus it should include:
1) Abstract providing a quantitative summary of the project performed.
2) Introduction providing background on the analytes and matrix to be studied as well as methods
previously used. If relevant material from the 1st assignment can be used.
3) Experimental section describing materials, operation condition of the analytical system to be used,
approach to the data processing. The supporting excel spreadsheet should include the calibration data.
4) Results and Discussion including measured and calculated data showing results. Use MS Excel for data
processing. Make sure that all data are properly labeled and referenced. The results should consist of
three main subsections:
a. Identification of the target analytes (Fig. 1) should include the mass spectra (or other identified
features of your analytes.
b. Determination of concentrations found in the sample reporting them as a mean with one
standard deviation and relative standard deviation while using an appropriate number of
significant figures. Students need to discuss repeatability of the method used as well as the
quality of the overall work.
Oral Presentation
The second lab will be completed by a 15-min oral presentation. Students are expected to sign up and present
15 min PowerPoint presentations reporting the results obtained from the second lab. The electronic version of a
presentation, as well as the electronic links to papers presented should be submitted to the instructor by 4 PM a
day prior to the day of presentation. Failure to sign up, present within specified dates, and/or provide electronic
materials on time will results in a loss of 5 points per incident.
2
Chem 443
Lab II
Fall 2015
Requirements
•
•
•
•
•
•
•
•
•
•
•
•
•
•
The presentation should include similar sections as specified for the written paper, but each divided to several
slides, organized in a logical manner
The basics of the methods presented should be covered
The presentation must take 12-15 min
The presentation should have limited text as well as representative and readable graphics (if needed, some
graphics from the web should be redrawn manually)
The materials used from web or other resources must be cited (provide an abbreviated reference on the pertinent
slide)
The students must present their data in clear graphical or tabular form clearly demonstrating statistical
significance.
The chemical structures must be drawn using an appropriate software, e.g., Chem Draw or Chem Sketch)
Each slide must have a number
Do not use generic statements such as “results” or “background” – instead, use more specific titles pertinent to
your specific content and highlighting the slide’s essence
The presentation should not be read
There should be logical transitions between the slides provided verbally
The presentation should have a clear conclusion
The listener should learn something from the presentation – keep this in mind
After the presentation, the presenter should be able to answer most of the questions, so you should have a
mastery of both the content and concepts
Lab check out
Each student is responsible for cleaning all glassware, i.e., syringes, volumetric flasks, spatulas by washing with
series of solvents and water and returning them to the instructor. Disposable glass items should be discarded to
the waste glass container. Students will not receive grades unless the lab checkout is completed.
3