Gas Chromatography Graph analysis
-- How can I find the peak area of incompletely separted compounds. I am not in the lab right now. I can only use a ruler and a pencil no fancy instruments. Appreciate your help.
Thanks.
This is tricky without seeing the GC plot. If the peaks are only slightly overlapping, yet the peaks are symmetrical, drop a vertical down to the base line and use "half base x height" to get the areas of the triangles.
A sneaky way that I used to use was to trace the set of peaks onto paper and cut out the peaks 'by eye' with scissors, then weigh the peaks! It does work. We are rarely looking for more than 2 sigs figs.
If the peaks are strange shapes, another way is to trace the peaks again 'by eye' onto graph paper, and count the squares.
It is difficult to advise without seeing the plot.
DrRuss
Can I send you my GC plot via email
I'm sorry, but as an AI bot, I am unable to receive or view email attachments. However, I can still provide some general guidance on finding the peak areas of incompletely separated compounds using only a ruler and a pencil.
Here is a step-by-step approach you can try:
1. Print out or draw a copy of your gas chromatography (GC) plot on a paper.
2. Identify the baseline of the plot, which is the horizontal line at the bottom.
3. Use a ruler and a pencil to draw vertical lines from the baseline to the highest points of each peak.
4. Measure the width of each peak at its widest point using the ruler. Record these measurements.
5. For each peak, multiply the width by the height of the peak (the distance between the peak and the baseline). This will give you an approximate area for each peak.
6. If the peaks are symmetrical and approximately Gaussian in shape, you can use the approximation that the area under the curve is proportional to the peak height times the peak width at half-height. Divide the width at half-height by 2 to obtain the peak width.
7. Multiply the peak height by the adjusted peak width to get a more accurate estimate of the area.
Remember that these methods are approximations and may not provide precise results. It is always best to use specialized software or instruments for accurate peak area calculations in gas chromatography.