Hi,
Just need a reminder on formulating custom calculation (Chemstation ver.C.01) as I haven't worked on it for years and feel something is missing from my memory. I have got several LC peaks with specific compound names, eg. A, B, C and D, and I need to build calculations arounds these peaks. Eg. to get ratios of (C+D)/(A+B) in different batches. How do I refer these specific compound peaks in a table to do the calculation?
Many thanks for anyone's help.
Hello,
You might want to look at using compound groups, if you need the summed peaks to change in the future it would be more flexible. If you use compound groups, you could setup something like what I have below. I created a group in IR with 2 fields, the sample name and a custom field, then repeated it by injection ID. Set a filter on the group for compound type = 4 which is named groups. Then in the custom field, I set the name to =Last(Compound_Name) & "/" & First(Compound_Name) and the value to =Last(Compound_AreaSum)/First(Compound_AreaSum). I did not test this in Chemstation but it should work in most versions as compound groups are setup differently but work the same way in IR. Please note this only works in cases where you have 2 distinct elements in your list of values for the field. Also, I have the names in the field to check the order. If your group names are not in the same order as mine, you will need to change the position of the first and last values in the ratio and name.
Marty
Hello,
You might want to look at using compound groups, if you need the summed peaks to change in the future it would be more flexible. If you use compound groups, you could setup something like what I have below. I created a group in IR with 2 fields, the sample name and a custom field, then repeated it by injection ID. Set a filter on the group for compound type = 4 which is named groups. Then in the custom field, I set the name to =Last(Compound_Name) & "/" & First(Compound_Name) and the value to =Last(Compound_AreaSum)/First(Compound_AreaSum). I did not test this in Chemstation but it should work in most versions as compound groups are setup differently but work the same way in IR. Please note this only works in cases where you have 2 distinct elements in your list of values for the field. Also, I have the names in the field to check the order. If your group names are not in the same order as mine, you will need to change the position of the first and last values in the ratio and name.
Marty
