[peroxide]

Hi everyone, Im new here. I have a question regarding analyzing a gas mixture with unknown concentration. It might be very simple, but I can't get my head around it.

I am going to analyze an unknown mixture of CO2 and CH4, I would like to determine the concentration of the unknown sample.

I have measured 5 samples (2 parallels each) of a calibration curve:

Sample 1: 50 mL calibration gas
Sample 2: 40 mL calibration gas + 10 mL N2 dilution
Sample 3: 30 mL calibration gas + 20 mL N2 dilution
Sample 4: 20 mL calibration gas + 30 mL N2 dilution
Sample 5: 10 mL calibration gas + 40 mL N2 dilution

The composition of the calibration gas is:
CO2: 2 %
CH4: 2.49 %
O2 (not quantified): 14.98 %
N2: Balance

The measured areas are given below:
Sample  Area (average of two parallells)
(Nr)                    (mV*min)
1   CO2:   56,54415      CH4: 70,6781
2   CO2:   44,2935        CH4: 54,6648
3   CO2:   33,7817        CH4: 41,64015
4   CO2:   21,7364        CH4: 26,984
5   CO2:   11,14795      CH4: 13,86585

The problem I have is how to plot this in a graph. How do I calculate the concentrations of the calibration points, considering their dilutions etc.

Thank you

[Arkcon]

The problem I have is how to plot this in a graph. How do I calculate the concentrations of the calibration points, considering their dilutions etc.

Thank you

Well, what have you tried so far?  Sorry to answer a question with a question.  But, this time at least, I'm not just parroting the forum rules.  Your question is a common one on these boards -- someone has data, and must determine some relationship, but has no idea what to chart.  Often, the dilemma comes up because of something similar to your specific case -- they have two sets of observed data.

To start to solve this sort of problem, you simply have to try:  build a spreadsheet for your tabular data.  Maybe you'll graph two lines, maybe you'll sum them two table entries and graph the sum, or determine the ratio, or add another constant (say the oxygen content) beforehand.  But none of this will ever make sense to anyone formatted  as two (or three) separate lists of numbers.