Table 1. KIMS assays for mCPP (A) and comparison of mCPP immunoassays (B).a
A.
Roche KIMS AssaySignalResult
mCPP concentration
    100 000 ng/mL168+
    20 000 ng/mL105+
    10 000 ng/mL84+
    5000 ng/mL31+
    1818 ng/mL−61
d-Amphetamine concentration
    1250 ng/mL (positive control)40+
    750 ng/mL (negative control)−85
    0 ng/mL−218
B.
ImmunoassayResult with mCPP spike of:
5000 ng/mL20 000 ng/mL100 000 ng/mL
KIMS+++
CEDIA++
Emit II
AxSYM
  • a (A), The KIMS assay is calibrated such that a signal of 0 corresponds to 1000 ng/mL d-amphetamine. Samples with signals ≥0 are reported as positive. Two QC samples run in parallel demonstrated that the assay and instrument were running properly (positive control, 1250 ng/mL d-amphetamine; negative control, 750 ng/mL), generating signals of 40 and −85, respectively. Drug-free urine generated a signal of −218. Although yielding a technically negative result, even at a concentration of 1818 ng/mL, mCPP generated a signal higher than the 750-ng/mL d-amphetamine control. (B), Results from 4 different immunoassays of a drug-free urine sample spiked with mCPP at 5000, 20 000, and 100 000 ng/mL: Roche KIMS Amphetamines II assay, Microgenics CEDIA Amphetamines/Ecstasy assay, Abbott Diagnostics AxSYM Amphetamine/Methamphetamine II assay, and Beckman Coulter Emit II Plus Amphetamines assay. Positive results (+) and negative results (−) are at the indicated concentrations.