Data Import

Igor is a data analysis and presentation software. It shares some functionality with spreadsheet software as Excel, but is much better adapted to handling spectra and related data.

It is best to read general description of Igor concepts here and in Getting Started booklet before proceeding. Do not worry if it appears too confusing. Try to get the general idea of 2D and 3D waves. 

Follow guidelines on importing matrix data into Igor. Import parameters depend on the origin of data, therefore make sure you use settings for importing HPSpec matrix data.

It is very important to give you imported data a meaningful name. Call it something like Trp_Conc_Abs. Avoiding common white space in names will help later in processing.

When data are imported as described, Igor will create three waves:

• A matrix wave that contain all absorption data that you measured; this wave is named the way you specified it, probably with 01 appended as a suffix.
• Row position (calibration) wave that contains wavelength for each row in the matrix. These correspond to different pixels across individual spectra that you measured. This wave is named as you matrix wave with RP_ prefix.
• Column position (calibration) wave contains time at which each spectrum was taken. This wave is named as you matrix wave with CP_ prefix. Since you have measured each spectrum separately, all values on CP_ wave will be pretty much the same.

Data import produces little visible effect, other than a report in the history window. While it is not necessary, you may want to display your waves in a table. From Windows menu choose New Table and select your new CP_ and RP_ waves; then from Table menu select Append Columns to Table and select your matrix wave – this way your small waves will be visible on the left of the table and not lost on the right, hidden side.  You will see the numbers contained in each wave and you will be able edit concentration values as necessary.

The key parameter that changed from spectrum to spectrum during titration is concentration of Trp. To make CP_ wave useful you need to replace values within with actual concentration for each spectrum (column) in the matrix. Proceed to calculate concentrations on the next page.

After calculations are complete, within Excel copy concentration values to the clipboard, return to Igor and paste calculated concentrations into CP_ wave. To paste values find the table displaying CP_ wave or make a new table with this wave, select the first cell of CP_ wave and press Ctrl+V.  Verify that CP_ wave has no empty cells and that number of rows in it equals number of columns in the matrix. Number of columns in the matrix can be found from import report in the history window or by examining information about matrix in Data Browser dialog (Data menu, bottom).