Extracted ion chromatograms showing quantification MRMs in authentic urine specimens containing A) 11.3, 18.3, 0.9, 1.8, 0.3 and 3.9 µg/l JWH-018 N-hydroxypentyl, JWH-018 N-pentanoic acid, JWH-250 N-5-carboxypentyl, AM2201 N-hydroxypentyl, MAM2201 N-hydroxypentyl and MAM2201 N-pentanoic acid, respectively, B) 0.2, 0.7, 0.2, 45.5, 6.7, 0.2, 1.4, 5.0, 10.2, 0.3, 36.4 and 0.2 µg/l JWH-018 5-hydroxyindole, JWH-018 6-hydroxyindole, JWH-073 N-hydroxybutyl, JWH-073 N-butanoic acid, JWH-122 N-hydroxypentyl, JWH-250 5-hydroxyindole, JWH-250 N-hydroxypentyl, JWH-250 N-5-carboxypentyl, AM2201 N-hydroxypentyl, RCS-4 N-5-carboxypentyl, RCS-4 M9 metabolite and UR-144 N-hydroxypentyl, respectively. Specimen B also contained 138.4 and 211.6 µg/l JWH-018 N-hydroxypentyl and JWH-018 N-pentanoic acid (determined after diluted re-analysis, data not shown). See Table 1 for peak numbering.