Determination of cathinone, cathine and norephedrine in hair of Yemenite khat chewers.

A sensitive and reproducible method for the quantitative determination of cathinone (CTN), norpseudoephedrine (NPE, cathine) and norephedrine (NE) from hair was developed. The compounds were extracted for 4 hours with phosphate buffer pH 2.0, followed by a standard solid phase extraction procedure on a mixed phase column, derivatization with heptafluorobutyric anhydride (HFBA) and GC-MS separation and quantification using D(3)-ephedrine (D(3)-E) and alpha-aminoacetophenone (AAP) as the internal standards. The diastereomers NPE and NE were satisfactorily separated. In the validation, the limits of detection and of quantification were determined at 0.03-0.08 ng/mg and 0.10-0.24 ng/mg, respectively and the interday standard deviation was between 10 and 15%. The method was applied to hair samples of 24 Yemenite khat chewers. All three compounds were detected in 23 of these cases. The concentrations ranged from 0.57 to 23.9 ng/mg for NPE, 0.19-25.0 ng/mg for NE and 0.11-22.7ng/mg for CTN. A highly significant correlation was found between the self-reported data about the khat consumption habits of the volunteers (4-56h chewing per week) and the concentrations of norephedrine and norpseudoephedrine in hair.