Table 3.

Mean±SD intra- and inter-assay recovery and imprecision for nicotine and metabolites in oral fluid

Analyte	Expected concentration (ng/mL)	Analytical recovery (% of target)				Imprecision (N=20, %CV)
		Intra-assay N=5		Inter-assay N=20		Pooled intra-day	Inter-day	Total
		Mean	Range	Mean	Range
Nicotine	3	110.2±2.6	(80.7–116)	99.8±9.6	(80.7–119)	5.2	12.1	13.1
	60	119.4±3.5	(93.1–120)	106±8.8	(93.1–120)	2.9	0.0	7.6
	600	112.4±5.3	(105–117)	111.4±4.3	(108–118)	3.4	0.0	3.4
Cotinine	0.6	93.2±3.8	(88–103.3)	98.4±4.1	(88–103.3)	0.0	3.3	3.3
	60	91.6±3.6	(88–116)	97.2±7.9	(88–116)	3.8	7.5	8.5
	600	110.2±3.3	(103–113)	108.5±2.7	(103–113)	2.3	1.0	2.5
OH-Cotininea	1.5	112.8±1.4	(92.7–115)	103.6±5.6	(92.7–115)	4.2	0.0	4.2
	60	115.8±2.2	(90.1–120)	101.2±9.2	(90.1–120)	2.4	9.9	10.2
	600	105.8±2.9	(99.5–110)	104.2±2.8	(99.5–109)	2.3	1.2	2.6
Norcotinine	3	109.1±2.1	(92.1–117)	102.7±6.7	(92.1–117)	4.3	6.3	7.6
	60	115.6±1.8	(85.7–119)	99.8±10.6	(85.7–117)	2.1	11.9	12.1
	600	109.0±2.4	(98.2–111)	105.4±4.3	(98.2–111)	1.8	0.0	1.8

^atrans-3′-Hydroxycotinine