A Human Oral Fluid Assay for D- and L- Isomer Detection of Amphetamine and Methamphetamine Using Liquid-Liquid Extraction

Table 7

Dilution study: percent difference from expected with a 4000 (2000) ng/mL standard diluted as indicated. All analytes are based at a 1 : 10 dilution.

Drug/Metabolite	1 : 5 dilution	1 : 10 dilution	1 : 20 dilution	1 : 50 dilution
Amphetamine	1.03	4.04	9.45	12.00
Methamphetamine	−8.17	−0.32	3.13	0.66
D-amphetamine	2.38	5.97	9.87	12.19
L-amphetamine	2.56	7.39	10.81	9.60
D-methamphetamine	−0.51	−3.58	−1.77	−3.63
L-methamphetamine	3.89	1.00	5.46	3.87

Indicates combined D- and L-. High concentration was 2000 ng/ml for individual D- and L-isomers.