Gas chromatograph manufacturerIt is widely used in petroleum, chemical, biochemical, pharmaceutical and health, food industry, environmental protection and other fields. In addition to quantitative and qualitative analysis, it can also determine physical and chemical constants such as distribution coefficient, activity coefficient, molecular weight and specific surface area of samples on stationary phases.
The manufacturer of the gas chromatograph did not detect any changes in the signal after injection, and the instrument did not produce peaks, resulting in a straight output. When encountering this situation, the sample should be checked one by one in the order from the sample injection needle, injection port to the detector.
Baseline issues with gas chromatograph manufacturers
Baseline fluctuations and drift in gas chromatography are baseline issues, which can increase measurement errors and sometimes even cause the instrument to malfunction.
1. When encountering baseline issues, it is necessary to first check whether the instrument conditions have changed and whether new gas cylinders and equipment accessories have been replaced recently.
2. If there is a replacement or change in conditions, it is necessary to first check whether the baseline problem is caused by these changes. Generally speaking, such changes are often the cause of the baseline problem. Some people have encountered this situation in their work: the purity of the new carrier gas is not enough, and after replacing the carrier gas, the baseline gradually increases (due to the purification tube of the carrier gas, the baseline does not change immediately). After booting up the next day, the baseline was very high and accompanied by strong baseline jitter, with all peaks submerged in noise and undetectable. After inspection, the problem occurred on the newly replaced carrier gas. After replacing the carrier gas again, it immediately returned to normal.
3. After excluding the possible causes of baseline problems mentioned above, it is necessary to check whether the injection pad is aging (it is a good habit to regularly replace the injection pad);
4. Should the quartz wool be replaced;
5. Is the lining pipe clean. It is worth mentioning that when cleaning the lining tube, it can be thoroughly soaked in a solvent with a constant volume after testing, then cleaned with ultrasonic waves for a few minutes, and then heated to a slightly higher temperature than the working temperature in a high-temperature furnace before reinstalling.
6. In addition, detector contamination may also cause baseline issues, which can be resolved through cleaning or hot cleaning methods.