Chiral analysis of ketamine enantiomers in human urine and hair: Application to authentic cases of ketamine use.
Journal of pharmaceutical and biomedical analysis August 15, 2025 Zhen Zhang, Yan Shi, Meiting Lin et al.
A UHPLC-MS/MS method was developed to separate and measure the two mirror-image forms (enantiomers) of ketamine in human urine and hair. After a deceased person used esketamine before death, only S-ketamine appeared in blood and urine, indicating that ketamine does not switch between its enantiomeric forms in the body. In 45 hair samples from ketamine abusers, the ratio of R-ketamine to S-ketamine ranged from 0.809 to 1.43, showing that illegal-market ketamine is mostly racemic (equal parts both enantiomers). A significant difference in this ratio was found between samples from China and Myanmar, likely due to regional variations in synthetic routes.