How would I compare using peak heights vs peak areas for GC quantitation?
Thanks
Either method works. Which method you select depends on how you graphed your calibration graph using standard solutions over a range of concentrations. For more information, download the online PDF file:
http://www.ffcr.or.jp/zaidan/FFCRHOME.nsf/7bd44c20b0dc562649256502001b65e9/146fd852cd5e269049256f32001a133e/$FILE/B14.pdf
You can compare the two methods by graphing the data from your set of standard solutions both ways and determining the concentration of an unknown using each graph.
Thank you GK
When comparing peak heights and peak areas for GC quantitation, there are a few factors that you need to consider. Both peak heights and peak areas represent different aspects of the chromatographic signal, and choosing the most appropriate option depends on your specific analytical needs and the nature of your sample.
Peak Heights:
1. Identify the peak: Firstly, you need to identify the peak you want to quantify in the chromatogram.
2. Measure the highest point: Measure the highest point of the peak vertically from the baseline. This peak height represents the maximum detector response for that compound.
3. Repeat the measurements: Repeat the measurements for multiple injections to obtain averaged peak heights.
4. Use calibration curve: Generate a calibration curve using standard solutions with known concentrations of the analyte. Plot the peak height against the known concentrations to establish a relationship.
5. Calculate the sample concentration: Measure the peak height of your sample and use the calibration curve to determine the concentration of the analyte in the sample.
Peak Areas:
1. Identify the peak: Identify the peak of interest in the chromatogram.
2. Measure the area under the peak: Determine the area under the entire peak by integrating the signal using appropriate software or algorithms.
3. Repeat the measurements: Perform multiple injections to obtain averaged peak areas for better accuracy.
4. Use calibration curve: Similar to peak heights, create a calibration curve by plotting the peak areas of standard solutions against their known concentrations.
5. Calculate the sample concentration: Measure the peak area of your sample and use the calibration curve to determine the concentration of the analyte in the sample.
Choosing between peak heights and peak areas depends on several factors such as the shape of the peaks, baseline noise, and whether the method is selective. Peak areas are generally considered more accurate and reliable, particularly for samples with complex backgrounds or overlapping peaks. However, both methods can be used effectively for quantitation, so it is recommended to validate the method's performance for your specific analytes and matrices.