Poor peak area precision/peak areas too small
Possible Cause | Remedial Action |
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Air bubbles in sample loop, needle, or metering device | Purge the autosampler. |
Vial empty | Check the sample level in the vial. If the sample level is too low, replace the vial with a filled one. |
Contamination or carry-over
Possible Cause | Remedial Action |
---|---|
Contamination in the system | Flush the system using an appropriate solvent. If you use water as solvent in pump channel A, flush it with 80% acetonitrile. |
Autosampler carry-over due to contaminated needle |
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Autosampler carry-over due to worn or damaged needle seat | Replace the needle seat (see Replacing Needle Seat and Needle Unit). |
Instable analysis or poor reproducibility
Possible Cause | Remedial Action |
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Unstable environmental conditions |
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Irreproducible gradient |
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Leakage
Possible Cause | Remedial Action |
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Capillary connections not installed properly or not tight |
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Sample problems
Possible Cause | Remedial Action |
---|---|
Sample is unstable and decomposes |
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Injection volume variation
Possible Cause | Remedial Action |
---|---|
Autosampler draws air from vial | There is not enough sample in the vial or the needle height setting is incorrect.
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Air trapped in autosampler flow path | Purge the autosampler. |
Gas content of sample too high or saturated |
Degas the sample if possible. |
Injector needle clogged or needle tip deformed | Run the script: D01 - Test System Back Pressure. Follow the instructions. |
Piston seals in autosampler metering device leaking | Run the script: D02 - Test System Tightness (What Should Be Tested = Sampler). Follow the instructions. |
Injection valve or other autosampler components leaking | Run the script: D02 - Test System Tightness (What Should Be Tested = Sampler). Follow the instructions. |
Needle seat worn out | Run the script: D02 - Test System Tightness (What Should Be Tested = Sampler). Follow the instructions. |