23 oct. 2017

Enable Auto Archiving - ISIscan™

Testing the PC Standardization (Part 1)

PCA standardization is part of the types of standardization algorithms used in Win ISI. We start with a REP file with a certain scan spectra from two different instruments (same samples scanned on both instruments and giving the same name to them). When we select PCA standardization we go to the option "Create a Score file from a spectra file", and we see that the option to create a PCS file is activated, so when we do it, apart from to get a PCS file we get also a PCA file.

This PCS file is used after to reduce our CAL file ( the one  we use to develop the calibration). When we use "Reduce", we see how we can use a PCS file as optional:
We will use the reduced output file to develop the calibration.

9 oct. 2017

How many samples are needed for a calibration?

One of the questions normally asked is: how many samples are needed for a calibration?, for how long I have to add samples to a calibration.

Of course what is necessary is calibration data from different years. At the beginning we can have a nice SEC but not so nice SECV or SEP, but as soon as we have more data from next years we will see how the SEC is increasing and the SECV and SEP are decreasing and are becoming closer to the SEC and the continue to become similar, but not bellow.
The idea is to continue adding samples and variability while SECV is significantly different than the SEC and while the SEP is significantly different than the SECV.