The only real way to do that is get a third party lab company local In Xi'an. I gues I can see if Anson will send a sample of the current lot over once they are found and the lab gets paid. That might be good since they would probably be familiar with Pioneer.
I would not trust a lab in Xi'an. They could have contacts with the supplier and not wish to offend them.
I've done this before in 2 ways:
1) The supplier takes the risk and sends the order on Net-30 terms.
During the 30 day window, I have the compound tested by my own laboratory. If the results show the correct compound and purity, I pay the supplier. If not, they have to pay for my shipping cost to send it back (and they are not very happy about that usually).
2) A 3rd party escrow service is used.
I pay the escrow service, the supplier ships the order. I then have the compound tested again, and either tell the escrow service to release the money to the supplier, or I send the compound back. This is not as nice as the first method because:
- The escrow service takes a percentage of the price
- The escrow time may not be long enough to get the test done, depending on how busy the lab is (my lab can take up to 3 weeks)
I recommend doing it one of these two ways.
Again, if someone wants to organize a group buy, I will be happy to get the testing done here in the USA in exchange for some of the material.