It's under their quality control statement.
Quality Control
Sorry, that does not mean they don't use Chinese nicotine. Read between the lines.
NICOTINE STATEMENTS
We do not import our nicotine
They get it from an American wholesaler who imports it from China at 99.7%
ECBlend does not work with or store raw or undiluted nicotine, we do not "cut" our nicotine, we buy nicotine pre-diluted in PG or VG base
Their nicotine is diluted by the wholesaler after they get it in pure form from China
TESTING: ECBlend obtains Laboratory Certificates of Analysis on our nicotine showing 99.7% pure nicotine. All nicotine for this category is diluted in Vegetable Glycerin(VG) or Propylene Glycol(PG) per our specifications prior to shipping to ECBlend. ECBlend then performs in-house titration testing to ensure the mg/ml is accurate within acceptable tolerance (+/- 2-4mg).
Their vendor takes the 99.7% Chinese nicotine (which, BTW, is less than pharma grade at 99.7%), and dilutes it to their specifications. ECBlend then tests it to make sure their wholesaler gave them what they paid for. If you buy 99.7% nicotine from China, they always will give you a Certificate of Analysis.
Each bottle of nicotine is tested on receipt in our facilities, using proper Nicotine Testing equipment by a qualified quality control member. Bottles are identified and results are logged.
If you buy pure nic from China, it will come with a batch number. Their vendor logs this batch number and ECBlends cross references it with the diluted nic base they get. That way, if a problem is found, it can be traced back to China and the wholesaler can notify any other juice maker who got diluted nic base from that same batch.
Nowhere on ECBlend's site does it say that they use American nicotine in their e-juice.
IMO, what they do say is borderline deceptive advertising, because they give that implication, as evidenced by people who interpret their statement to mean that they use US nicotine.