Periodically check the needle for blockages or particulate matter that may restrict the flow of samples into the ICP. If repeated cleaning attempts fail to remove blockages or if the needle is restricting the flow of the sample, replacement is necessary.
Physical damage: If the needle is visibly bent, cracked, or frayed, it should be replaced immediately.
Wear and tear: Over time, chemical exposure can degrade the Teflon material, leading to leaks or inconsistencies in sample introduction.
