Are there significant differences in the analysis results between domestic fluorescent sulfur and imported fluorescent sulfur? ?
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When we analyze finished gasoline and refined gasoline, as well as reference samples and naphtha, there is no difference between domestic and imported fluorescence sulfur analyzers (Antek). However, for a type of oil called high-octane aromatics, the domestic analyzer gives a result of 11 ppm, while the imported analyzer shows a value of over 30 ppm. We’re not sure what the reason for this is; the problem seems to lie with this particular oil. This high-octane aromatic oil has an octane rating of over 100, with an aromatics content of over 80%. Has anyone else conducted comparisons or encountered such a situation? As for the results of this oil analysis, it is unclear whether domestic or imported machinery dominates.
This post was last edited by qugd on 2015-9-14 21:20. Please check the source of that high-octane aromatic oil. For reformed oil produced by reforming, the total sulfur content should be very low, generally below 1 ppm, unless there is contamination during transportation and storage. However, if oil is obtained through direct coal liquefaction, the sulfur content will be higher. Regarding the data deviations that occur during the analysis process, especially those between different analytical instruments or methods, it is necessary to carefully examine the conditions and status of the instruments in order to identify the causes of these deviations. It is also best to use standard samples to verify the analyzer. The ultraviolet fluorescence method for determining total sulfur relies on mature methods and instruments; however, with regard to the instruments themselves, the measurement conditions may cause some random and systematic deviations in the results, but there should not be significant errors in the data. It is recommended to carefully investigate the reasons from the aspects of analysis methods and instrument conditions.
Are the cracking tube temperatures the same for domestic and imported equipment? Can octane-rich aromatic oils burn completely? I agree with what senior qugd said: for oils with a high octane content and an aromatic content of over 80%, the sulfur content should be low. Less than 1 ppm – is the method curve selected correctly?
The imported analyzer showed good repeatability when analyzing this sample, and the domestic analyzer also exhibited good repeatability; however, the results were different. The combustion temperature in the former device was 1050 degrees, while it was 1000 degrees in the latter. Could it be that the sample did not burn completely? Additionally, when testing the boiling range of this high-octane aromatic compound, a small amount of waxy substance appeared at the condenser – it’s not clear what that substance is
The reference samples are fine; there is no problem with either instrument. This problem occurred only when analyzing the sample
What is the concentration of the standard sample? It is advisable to try using a standard sample with an approximate concentration. Additionally, to verify the accuracy of the test results, a certain amount of sulfur standard can be added to the samples to check whether there are any abnormalities in the results. It is best to double the concentration after adding the standard, as this yields the best results.
We have encountered this issue as well; the nitrogen content in this oil is high, and the imported instruments calculate the wavelength corresponding to part of that nitrogen as if it were sulfur, which results in higher values. To ensure reliability, we choose the larger value, as there are also many imported devices in sampling or comparisons.