Reasons why gas chromatography has poor parallelism when making samples
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What is the reason for poor parallelism during gas chromatography sampling? How to solve it?
There are many reasons, including method problems, column oven temperature rise program settings, and sample preparation standards. This requires detailed analysis of specific issues. It is recommended to ask an expert to take a look.
It is recommended to use the internal standard method. The standard curve method will cause non-parallelism because the injection volume is not easy to be accurate or there is air leakage in the system. The internal standard method can overcome the disadvantages of inaccurate injection volume or air leakage because the standard and the sample are injected at the same time.
Chromatographic stability and injection level affect parallelism
First of all, it depends on which method you use. The reasons for poor parallelism are also different. If the instrument is running continuously and the results are different when two samples are taken at the same time, it is necessary to consider the problem of the instrument itself. Problems with the inlet, whether there is a split flow, whether there is air leakage in the system, whether the concentration is very low (below 10ppm)