[phillyj]

We had done some Gas chromatography readings and the text had advised us on methods to find the amount of the products that had eluted. One method was to find the area under the curve (calculus) and the other was to cut up the curve and weigh it on a scale. That second method confused me. It doesn't seem very accurate and would all GC papers weigh the same? We're talking microscale organic labs so i don't think it makes much sense. Why is this method described and how accurate is it?

[agrobert]

This is how it was done in the past.  It is in you book to make you realize that the area under the curve (AUC) is relative to the total area of all curves.  So assuming the paper has some uniformity in weight it can be accurate to cut all of the curves out and weigh them.  This was done before computers could integrate the AUC for you.  Mathematical techniques can be used as well but they are tedious.  Cutting papers and weighing them is fast and reliable if you don't have computers.