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Simultaneous determination of methylphenidate and ritalinic acid in hair using LC-MS/MS

Moonhee Jang1, Jihyun Kim1, Ilchung Shin1

  • 1National Forensic Service, 139 Jiyang-ro, Yangcheon-Gu, Seoul 158-707, Republic of Korea.

Forensic Science International
|December 12, 2018
PubMed

Insights

This study developed a sensitive method to detect methylphenidate (MPH) and ritalinic acid (RA) in hair. Analysis of illicit drug users revealed MPH concentrations from 1.0 to 265.0 pg/mg, providing crucial forensic data.

Area of Science:

  • Forensic Toxicology
  • Analytical Chemistry
  • Pharmacology

Background:

  • Methylphenidate (MPH) is a widely prescribed stimulant for ADHD, with increasing rates of abuse.
  • Existing analytical methods for MPH in hair lack reporting on its metabolite, ritalinic acid (RA), in abuse cases.
  • Determining MPH and RA concentrations in hair is crucial for forensic investigations.

Purpose of the Study:

  • To develop and validate a sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for simultaneous MPH and RA determination in hair.
  • To report the concentration ranges of MPH and RA in hair samples from individuals abusing MPH illicitly.
  • To provide reliable analytical data for forensic settings related to MPH abuse.

Main Methods:

  • Development and validation of a sensitive LC-MS/MS method for MPH and RA detection in hair.
  • Sample preparation involving simple methanol extraction from 10mg of hair.
  • Method validation demonstrated low limits of detection (LODs) and quantification (LOQs) (0.5-1 pg/mg) with good linearity, precision, and accuracy.

Main Results:

  • The validated method achieved LODs of 0.5 pg/mg for MPH and 1 pg/mg for RA, with LOQs of 1 pg/mg for both.
  • Analysis of hair samples from ten illicit MPH users showed MPH concentrations ranging from 1.0 to 265.0 pg/mg.
  • Ritalinic acid (RA) was detected at concentrations below the limit of quantification up to 76.3 pg/mg.

Conclusions:

  • A sensitive and reliable LC-MS/MS method for simultaneous MPH and RA analysis in hair was successfully developed and validated.
  • The study provides the first reported concentration ranges for MPH and RA in hair from MPH abuse cases.
  • Findings offer valuable forensic insights into MPH abuse patterns, often alongside other illicit substances.
Keywords:
HairLiquid chromatography-tandem mass spectrometryMethylphenidateRitalinic acid

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