Gas chromatograph failure and maintenance methods

Gas chromatograph failure and overhaul methods:

First, the failure of the chromatographic peak after the sample injection: The gas chromatograph has no change in the detection signal after the sample is injected, the instrument does not produce a peak, and the output is still a straight line. In this case, check one by one from the sample syringe, the inlet to the detector. 1, first check the syringe is blocked, if there is no problem, 2, then check the inlet and detector graphite gasket is tight, not leaking, 3, and then check the column for leaks. 4, finally observe the detector outlet is open.

Second, the baseline problem: baseline gas chromatography, drift is a baseline problem, the baseline problem can increase the measurement error, and sometimes even cause the instrument can not be used normally. 1. When the baseline problem is encountered, check whether the instrument conditions have changed and whether the new cylinder and equipment accessories will be replaced in the near future. 2. If there are changes or conditions change, it is necessary to first check whether the baseline problem is caused by these changes. In general, this change is 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 the base line gradually rises after replacing the overload gas (the baseline is not changed immediately due to the carrier gas purge tube). After starting the next day, the baseline was very high and accompanied by a strong baseline shake. All the peaks were lost in the noise and could not be detected. After inspection, the problem occurred on the newly replaced carrier gas. After replacing the carrier gas, it immediately returned to normal. 3. When the above reasons that may cause the baseline problem are excluded, you should check whether the sample pad is aging (you should develop a good habit of regularly changing the sample pad); 4. Is it necessary to replace the quartz wool?

Third, the fault caused by the loss of the first case can be solved by multiple empty operation and cleaning gas path (inlet, detector, etc.). 1. In order to reduce air pollution, the following measures can be taken: The high-temperature cleaning process should be performed in the final stage of temperature increase; 2. The sample injected into the inlet should be clean; 3. The use of high-boiling oil substances should be reduced. 4, use the highest possible inlet temperature, column temperature and detector temperature.