I do not know the independent lab Amsoil is using in their claims. But Oil Analyzers or Polaris are the likely candidates. AFAIK, Oil Analyzers is a division of Amsoil, but I don't see much mention of this in the literature.
https://allsynoil.com/oil_analysis.html
https://www.amsoil.com/shop/by-product/motor-oil/racing/dominator-5w-20-racing-oil/
"Oil Analyzers Inc®. (715-395-0222) is a division of AMSOIL that provides cost-effective, quality oil analysis services"
Have not seen any mention of fuel not emulsifying into the oil. The focus has been on neutralizing the effect of fuel on oil through stronger base stocks and proper additive chemistry.
https://allsynoil.com/oil_analysis.html
https://www.amsoil.com/shop/by-product/motor-oil/racing/dominator-5w-20-racing-oil/
"Oil Analyzers Inc®. (715-395-0222) is a division of AMSOIL that provides cost-effective, quality oil analysis services"
Have not seen any mention of fuel not emulsifying into the oil. The focus has been on neutralizing the effect of fuel on oil through stronger base stocks and proper additive chemistry.