1,5,5-Trimethylhydantoin (TMH) is a non-isotopic internal standard (IS).

Arctiin(NSC 315527), a plant lignan that can be extracted from the Arctium lappa (burdock) seeds, is a possible environmental endocrine disruptor compound and have been shown to influence sex hormone metabolism as well as protein synthesis, steroid biosynthesis.

Tryptophanamide belongs to the class of organic compounds known as tryptamines and derivatives. Tryptophanamide has been detected in multiple biofluids such as urine and blood.