But if they got say 200 barrels of some chemical, do they test each barrel or just 1, or does the company that supplies it do a test on the batch and then submit those results. Most metallurgical companies will do their testing on a sample from each batch then submit the results of those tests on the batch that way you know the purity of any compounds you are purchasing before hand. Granted after this they are most certainly going to investigate this and they better implement stricter testing on their supply chain before use. So with out knowing how they were doing their material QC it is all speculation, but I know there were similar incidents happened to Rio-Tinto last year when one of their plants that supplied a lot to China suddenly had far more silicon dioxide in it than the batch tests indicated which led to a very poor quality yield and set them back months, while the Chinese state used that to push some over to their own state owned plant that was able to meet their demand. Same story with a Japanese Steel manufacturer that was supplying China with some finished steel a year or 2 ago and again it was used to push a campaign getting local manufacturers to buy from a local state owned steel mill while giving a competitor a black eye. I just think the timing is a tad sketchy...It's almost difficult to believe they don't test their chemicals for identity and purity before use.
In biopharma itis a regulatory requirement to as part of incoming inspection to do identity and purity testing in a QC lab using some sort of HPLC or LCMS method.
Sure these things cost money, but they are WAAAAAAY cheaper than losing several lots of silicon.