Table 2

Urine metabolite excretion as a percentage of total recovery

Species^2-a	Deuterium-Labeled
Species^2-a	Pregnant	Postpartum
	%
Nicotine	5.6^2-150	28.9
	(3.4–7.8)^2-b	(10–47.5)
Nicotine N-glucuronide	7.7^2-150	5.1
	(4.6–10.9)	(2.6–7.7)
NicotineN-oxide	9.0	14.3
	(5.3–13.0)	(8.2–20.3)
Cotinine	18.3	17.7
	(11.2–25.4)	(10.6–24.8)
Cotinine N-glucuronide	14.1^2-160	6.5
	(9.4–18.7)	(2.3–10.8)
3′-Hydroxycotinine	36.4^2-160	21.1
	(31.6–41.6)	(14.8–27.4)
3′-OH-Cot-O-glucuronide^2-c	8.9	6.4
	(2.3–15.6)	(1.2–11.5)

The numerator is the molar amount of each species listed in the first column. The denominator is the molar sum of all the species.

↵2-150 P < 0.05;
↵2-160 P < 0.001.
↵2-a Nicotine and all metabolites are from nicotine-d₂.
↵2-b Means and 95% confidence intervals.
↵2-c 3′-Hydroxycotinine-O-glucuronide.