An anti-ketamine molecularly imprinted polymer (MIP) was synthesized and used as the sorbent in a solid-phase extn. protocol to isolate ketamine and norketamine from human hair exts. prior to LC-MS/MS anal. Under optimized conditions, the MIP was capable of selectively rebinding ketamine, a licensed anesthetic that is widely misused as a recreational drug, with an apparent binding capacity of 0.13 μg ketamine per mg polymer. The limit of detection (LOD) and lower limit of quantification (LLOQ) for both ketamine and norketamine were 0.1 ng/mg hair and 0.2 ng/mg hair, resp., when 10 mg hair were analyzed. The method was linear from 0.1 to 10 ng/mg hair, with correlation coeffs. (R2) of better than 0.99 for both ketamine and norketamine. Recoveries from hair samples spiked with ketamine and norketamine at a concn. of 50 ng/mg were 86% and 88%, resp. The method showed good intra- and interday precisions.
- liquid chromatography
- bioanalytical chemistry