Table 2.

Sensitivity, average and standard deviation of the blank signal, and limit of detection for several drugs analyzed using PS-MS

Drug	Internal standard	Sensitivity (m)/mLng−1× 10−1)	xb ± sBb	LOD/ng mL−1	Therapeutic rangea/ng mL−1
propranolol	atenolol	3.4	0.4 ± 0.2	106	20–300
atenolol	propranolol	1.5	0.06 ± 0.02	34	100–1000
verapamil	imatinib	6.3	0.031 ± 0.005	3	50–250
lidocaine	atenolol	18	0.06 ± 0.02	4	1000–6000
amitriptyline	atenolol	4.6	0.013 ± 0.009	6	50–200

^aTherapeutic range given is in serum or plasma, which may differ from the concentration in whole blood.

^bx_B = average signal of the blank, s_B = standard deviation of the blank.