Chromeleon Slope Formula

[Pear]

Hi,

I'm having some trouble with Chromeleon's calculation of my calibration curve slope.

Using the following data:

Response--------Cal Value
0.4105-----------0.10
0.8232-----------0.20
2.0718-----------0.50
4.1295-----------1.00
10.4837----------2.50

I get a slope in excel of 4.1979 using the =SLOPE function. Chromeleon reports this slope as 4.1828 which does influence results somewhat.

Unfortunately I need to export my Chromeleon results for some further data processing in excel (blank subtraction on select samples only which Chromeleon doesn't really like) and so would really like these two slope values to line up.

I've had a look through Chromeleon's help and can't find the exact formula they use, so hoping somebody here may have some experience with this?

Thanks for any help.

[vmu]

4.1979 is the slope a for y = a*x + b, with b = -0.0264 from your data.
4.1828 is the slope a for y = a*x.

Both equations can be chosen for the data approximation in Chromeleon and Excel.

[Pear]

4.1979 is the slope a for y = a*x + b, with b = -0.0264 from your data.
4.1828 is the slope a for y = a*x.

Both equations can be chosen for the data approximation in Chromeleon and Excel.

AH DOI. It's been a long day. Thank you so much.