What chemicals are you looking for? Most likely, if you are not going to buy container-loads, viz., 35-40,000 pounds it would be easier to buy domestically.
I have bought chemicals from China for over eighteen years, and it has always been a hassle. The preliminary sample has always been in spec, but once you actually begin to purchase in substantial quantities they start sending over complete ****. Which puts you in a real bind because you don't have a workable product and they have your money. If you think that you can sue them, think again. Rarely can you sue for damages in China because either the government won't accept the case and you ought to know that each company is also partially owned by the government.
Whenever I state that you can't trust the Chinese I get attacked for racism, but my personal experience tells me not to trust the Chinese businessman, because they are liars.
You would be better off trying the Indians. At least in India they speak English, so there is no confusion, and you can sue for damages more readily in India than China.