I voted Triton as it's what I use, but I didn't notice you asked which one was "best".
Actually I have no idea and TBH, I don't think many (any) of us would be able to compare the ICP-OES services with any benchmark for accuracy.
There appear to be differences in detection although again, the comparisons I've seen on blogs and Youtube have been lacking in reliable methodology. Taking samples at different times etc. One even failing to read basic instructions about rinsing 3 times, then going onto some bizarre claims about the provider not giving him enough sample tubes (he read rinse 3 times as fill 3 tubes...).
So for me, it comes down to experience, in-house expertise and critically the information, sources and suggested remedies.
This, for me is where the original provider of the mass market ICP-OES test, Triton, scores much higher than the competition.
In-house ICP-OES and a LOT of experience
Triton use in-house machines and went through a LOT of testing to get where they are now, including how to get reliable ICP-OES results from seawater. How the presence of one element affects detection of another etc.
What do you do with the results?
Triton also have a lot of advice to their customers about what the elements do (not all of them, but a lot) and critically where sources of contamination could be AND what to do about them.
Now I've not used any other providers because of my good experiences with the above, however I do see a LOT of ATI users asking for help from Triton on the results.
This suggests to me that they are somewhat lacking on this info and experiene. This may be perception, but I think it's valid observation.
So for me, I've no bad experiences of anyone offering the services, and would not draw comparisons between the accuracy of the services. But I feel far more confident and comfortable trusting Triton with the testing and interpretation of the results.
