Chem 231 128 Lecture Introduction Goals of Course

Chem. 231 – 1/28 Lecture

Introduction Goals of Course • Discussion of More Practical Aspects of Separation Science • Provide Specific Lab Training in Use of Chromatography Instruments and Simple Separations (e. g. Extractions) • Facilitate Semi-Independent Student Learning • Improve Communication Skills

Syllabus Class/Discussion Meeting Times • Not exactly as in syllabus • We typically have extended discussions and instrument demonstrations in the beginning • We will end discussion “lectures” about half the way through the semester; Discussions will then occur for 3 rd lab oral presentations • Some work can be performed outside of class hours (once first lab is completed) provided work doesn’t interfere with other classes and follows department policy

Syllabus Website + Discussion • Additional Course Information on Website • Discussion Topics – In past, I covered “practical” topics I thought were important – I expect topics to be divided between general “practical” information and information specific for the experiments to be performed

Syllabus Laboratory Experiments • Set 1 Labs – Relatively simple experiments to demonstrate use of HPLC and GC – Will need to do both laboratory experiments – One will include quantitative work that will be reported while the other will just be for competency

Syllabus Laboratory Experiments • Set 2 Labs – Both labs use extraction methods as would be typical for extraction of compounds from complicated matrices – HPLC lab will use solid phase extraction to trap phenols from an aqueous matrix – GC lab will use solid phase microextraction to trap volatile compounds from gas

Syllabus Laboratory Experiments • Set 3 Labs – The focus of these experiments will be to derivatize fatty acids and carbonyl compounds for subsequent analysis by GC and HPLC – Students will provide additional samples of interest

Syllabus Laboratory Experiments • Term Project Labs – These are meant to be more independent – Students can isolate an ingredient from a household product or – Students can work on a separation using equipment beyond that used in the first 3 experiments (e. g. use HPLC with fluorescence detection)

Syllabus - Notes on Grading • Homework and Quizzes – 10% of grade – In discussion and on discussion materials • Final Exam – 15% of grade – No date set yet because previously given after discussion lectures end after set 2 labs begin – Good dates would be the Monday before or after Spring Break

Syllabus - Notes on Grading (2) • Lab Reports – 75% of grade – Will submit 4 formal written reports (one for each lab + for the term project) (65% of grade) – Will submit one ungraded report for the other set 1 lab (e. g. formal for HPLC and informal for GC) – Will give one oral report on your particular sample in the (Set 3) derivatization lab (10% of grade)

Lab Safety • Safety Equipment Required – Goggles, gloves and lab coats needed – Must wear long pants and shoes covering feet below ankle – Goggles and lab coats should be worn while running instruments, but gloves only needed when handling chemicals – Gloves should not be worn outside of labs (people get concerned that you are spreading toxic compounds) – Gloves can both protect your hands from chemicals (e. g. from dinitrophenylhydrozene) and protect your samples from your hands (e. g. from fatty acids)

Other Lab Equipment Needed • Lab Notebook (and pen) • Lab Instructions (see e. g. Set 1 Lab Instructions) • Notes from Discussion • Memory stick/floppy drive

Discussion Topics • Practical Aspects of Separation Science – example: demonstration and discussion of how SPE cartridges work and are used • Specific Tools Needed for Our Labs – example: how to set up file folders to save data using the Agilent HPLC

Today’s Discussion Topic: Data Processing • • How to Set Up Folders Saving Raw and Processed Data Excel Processing of Raw Data External Standard Calibration Using Excel

Today in Lab • Check in to lockers

Data Processing How to Set Up Folders • Whenever possible, use your own folders • Advantages: – All your stuff should go there – Nobody else’s stuff should go there – Easier to find data/methods and less likely to have data overwritten • Disadvantages: – it takes a little time to set up Example: Chemstation

Data Processing Saving Raw Data I • Raw Chromatographic data consists of time and response(s) (response for a single channel instrument to responses for multichannel instruments) • Most software programs allow you to obtain raw data • For some instruments (Buck GC), data presented using Excel looks nicer than software chromatograms (with the exception of no integration)

Data Processing Saving Raw Data II • Steps in Process: – Open file (in Chem. Station, you need to be in Data Analysis mode) Example: Chemstation

Data Processing Saving Raw Data III • Steps in Process: – Look for way to “export” file or “save file as” with the output being a “text” file (these usually have a. txt extension) In Chem. Station, text file made as “CSV” file

Data Processing Saving Raw Data IV • Steps in Process: – Once in text format, you can open using “notepad”, but best to move to Excel – Demonstrate opening Expfil using notepad and in Excel

Data Processing Saving Processed Data I • For Lab Reports, you will want to incorporate chromatograms • Besides switching raw data to Excel, you also can use instrument software plots In Chem. Station: use Graphics → Copy to Clipboard The Alternative (used extensively for these Powerpoint slides) is SHIFT Print Screen: This Copies the Screen Demonstrate Both of these methods allow you to paste chromatograms into other programs

Data Processing Saving Processed Data II • Besides the chromatogram, one often wants other chromatographic data (e. g. retention time, peak area, etc. ) • In Chem. Station, this can be copied by using the Control C key Click and drag over data box • Then in Excel, the data can be pasted

Data Processing Data Smoothing in Excel • Demonstrate using trendline for a running average and also using average function with Excel