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- Posts: 3
- Joined: Thu May 11, 2006 9:51 am
Hello everybody
we have a problem with the autosampler in our new (one year old)Shimadzu GC/MS system. The autosampler is the AOC-20. The problem is with the syringe, we had to replace it 5times the last year due to the same problem.For some reason the plunger is bended and made crooked from the autosampler. At first we thought that it was contaminated but now the last time it happened although ten days earlier the syringe was cleaned with washing with acetone and even now planger and syringe seem clean in eye look.
For GC/MS analyses we use derivatization method of BSTFA TMCS 1-10% in pyridine as solvent.The syringe is programmed to be washed with solvent (acetone) 5 times before and after injection for each analyses and at the end of each batch process we put a vial with acetone or methanol to be injected for one more circle of injection process, but without sample.However it is still bending and we have to replace it 5 times already. This is happening always when a batch process starts. The last was although the analysis was without derivatization process with the use of acetone as solvent and the plunger didn't seemed to be so much stiffed.
If someone had face similar problem with syringe and can help us or if someone has any idea of what we should do to avoid it we will be thankfull.
Thanks in advance for every reply
we have a problem with the autosampler in our new (one year old)Shimadzu GC/MS system. The autosampler is the AOC-20. The problem is with the syringe, we had to replace it 5times the last year due to the same problem.For some reason the plunger is bended and made crooked from the autosampler. At first we thought that it was contaminated but now the last time it happened although ten days earlier the syringe was cleaned with washing with acetone and even now planger and syringe seem clean in eye look.
For GC/MS analyses we use derivatization method of BSTFA TMCS 1-10% in pyridine as solvent.The syringe is programmed to be washed with solvent (acetone) 5 times before and after injection for each analyses and at the end of each batch process we put a vial with acetone or methanol to be injected for one more circle of injection process, but without sample.However it is still bending and we have to replace it 5 times already. This is happening always when a batch process starts. The last was although the analysis was without derivatization process with the use of acetone as solvent and the plunger didn't seemed to be so much stiffed.
If someone had face similar problem with syringe and can help us or if someone has any idea of what we should do to avoid it we will be thankfull.
Thanks in advance for every reply
