Tris(2-carboxyethyl)phosphine or TCEP is a potent, versatile, odorless, thiol-free reducing agent with broad application to protein and other research involving reduction of disulfide bonds. Because TCEP does not contain thiols, it does not have to removed from solutions before performing reactions involving maleimide labeling or cross-linking reagents. TCEP may be used as a substitute for DTT or 2-mercaptoethanol (2-ME) in reducing sample loading buffer for SDS-PAGE. One strategy for labeling antibodies involves reducing disulfide bonds in the hinge region of IgG molecules without also reducing those connecting heavy and light chains.

Ritalinic acid is an inactive, major metabolite of methylphenidate, a schedule II drug in the United States commonly used as a psychostimulant drugs methylphenidate and ethylphenidate. The elimination half-life of methylphenidate is relatively short (approximately 2 hours); therefore it is also available in extended release (ER) forms. The main metabolite is ritalinic acid, and the methylphenidate metabolites are mostly excreted in urine.