Personally, I think the first two are more common. Shimadzu's price is relatively low, and it is very durable. It's generally well maintained. In addition to replacing the consumed accessories, it is common for the instrument to be used for more than ten or twenty years. There are many Shimadzu used in general factories.

Agilent's price is higher, but the workstation certification is better. That is to say, you can't crack it, and you can't fake the chromatogram and time. R&D enterprises use it more.

Waters National Research Institute uses it more, but not much for evaluation.

If you buy these instruments, you should train them. One time, the engineer went to the door to install it and taught the experimenter simple operation. The other free training was a relatively comprehensive training given away, which lasted about two or three days.

It is best not to recommend domestic brands or some miscellaneous brands. After-sales service, training, maintenance and daily operation are all problems. After all, instruments should be commonly used, and it is best to have a better brand.