Chem. 133 – 1/26 Lab Lecture

Lab Topic: Data Processing

• How to Set Up Folders• Saving Raw and Processed Data• Excel Processing of Raw Data

Data ProcessingHow 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

overwrittenExample: Chemstation

Data ProcessingSaving Raw Data I

• Typical instrument data consists of wavelength or time and response(s)

• 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 ProcessingSaving Raw Data II

• Steps in Process:– Open file (in ChemStation, you need to be in

Data Analysis mode)

Example: Chemstation

Data ProcessingSaving 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 ChemStation, text file made as “CSV” file

Data ProcessingSaving 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 ProcessingSaving Processed Data I

• For Lab Reports, you will want to incorporate chromatograms and spectra

• Besides switching raw data to Excel, you also can use instrument software plots

In ChemStation: use Graphics → Copy to Clipboard

The Alternative (used extensively for these Powerpoint slides) is SHIFT Print Screen:This Copies the ScreenDemonstrate

Both of these methods allow you to paste chromatograms into other programs

Data ProcessingData Smoothing in Excel

• Demonstrate using trendline for a running average and also using average function with Excel