Concerning synthetic estrogens, very little information is available, and their presence in milk and derivatives is very rare. For example analyzed 103 samples and only detected A/B in one of them at concentrations of 3.03 and 0.37, respectively. Also analyzed seven batches of milk products from four manufacturers with different fat, peotein and carbohydrate content, finding DES in two batches at a concentration under the LOQ of the method.