Table 1.

Composition of calibrators, controls and samples

Calibrators/Controls/Samples	Volume of spiking solution (µL)a	Volume of internal standard solution (µL)b	Volume of extraction solution (µL)c	Final concentration of LBT-999 (pg/mL)
Cal 1	100	100	300	3.75
Cal 2				12.50
Cal 3				25
Cal 4				125
Cal 5				375
Cal 6				1250
Cal 7				2500
Low QC				100
Medium QC				1000
High QC				2000
Sample	100d			–

(a) LBT-999 solutions in water, (b) Cocaine solution (2.5 ng/mL) in water, (c) MeOH/Water (8:2), (d) Water solution without LBT-999. Low, medium and high QC refer on the LBT-999 concentration in the QC samples based on the calibration curve