Abstract: After long-term use of gas chromatograph, the inner diameter of the shunt line gradually becomes smaller, or even completely blocked. After the split line is blocked, the inlet of the instrument shows abnormal pressure, the peak shape becomes worse, and the analysis result is abnormal. During the maintenance process, regardless of whether it is possible to determine whether the shunt line is clogged in advance, the shunt line needs to be cleaned.
The gas chromatograph TCD detector may be contaminated by sediments from the column or other substances entrained in the sample during use. Once the TCD detector is contaminated, the baseline of the instrument jitters and noise increases. It is necessary to clean the detector.
The Agilent TCD detector can be thermally cleaned as follows: Turn off the detector, remove the column from the detector connector, plug the detector connector in the oven with a dead plug, and set the reference gas flow rate To 20 ~ 30 ml / min, set the detector temperature to 400 ° C, heat wash for 4 ~ 8 h, and use it after cooling down.
The domestic or Nissan TCD detector pollution can be used in the following methods: after the instrument is shut down, remove the air inlet of the TCD, use a 50 ml syringe to sequentially remove acetone (or toluene, different solvents can be selected according to the chemical nature of the sample), absolute ethanol Distilled water is repeatedly injected from the air inlet 5 to 10 times, using a suction ball to slowly blow out air from the air inlet to blow out impurities and residual liquid, and then reinstall the air inlet connector, after starting up, the column temperature is raised to 200 ℃, detection The temperature of the reactor rises to 250 ℃, and a carrier gas that is 1 to 2 times larger than the analysis operation gas flow is introduced until the baseline is stable.
For severe pollution, the air outlet can be blocked with a dead plug, filled with acetone (or toluene, different solvents can be selected according to the chemical nature of the sample) from the air inlet, maintained for about 8 h, and the waste liquid is discharged, and then the above method deal with.
Cleaning of FID detector: FID detector has good stability in use, relatively low requirements for use, and is generally used, but during long-term use, problems such as detector nozzles and carbon deposits, or organic matter are prone Depositing at the nozzle or collector, etc.
For problems such as FID carbon deposition or organic matter deposition, the organic solvent such as acetone, toluene, and methanol can be used to clean the detector nozzle and collector. When the carbon deposit is thick and cannot be cleaned, the thick carbon deposit of the detector can be carefully polished with fine sandpaper. Be careful not to damage the detector during the grinding process. After the initial polishing is completed, the contaminated part is further wiped with a soft cloth, and then finally cleaned with an organic solvent, which can generally be eliminated.
Baking Pans,Round Baking Pan,Steel Pizza Pan,Non-Stick Pizza Pan
vchomy , https://www.ivchomy.com