(±)-threo-Ritalinic acid-D₄ HCl, 100 µg/mL (as free base)

(±)-threo-Ritalinic acid-D4 HCl 100 µg/mL (AFB) 1 mL This stable-labeled internal standard of (±)-threo-ritalinic acid is suitable for a wide variety of GC/MS and LC/MS applications from clinical toxicology and urine drug testing to forensic analysis and isotope dilution methods. Ritalinic acid is the major urinary metabolite of methylphenidate, more commonly known by the brand name Ritalin that is approved for treatment of ADHD (Attention-Deficit Hyperactivity Disorder) and narcolepsy.