Table 1.

Certified mass fraction values (μg/kg) for OH-PAHs in SRM 3672 organic contaminants in smokers’ urine and SRM 3673 organic contaminants in non-smokers’ urine

	SRM 3672	SRM 3673
1-Hydroxynaphthalene(a,b,c)	33.8±4.3(d)	207±33(e)
2-Hydroxynaphthalene(a,b,c)	8.57±0.16(d)	1.32±0.03(d)
9-Hydroxyfluorene(a,b,c)	0.331±0.077(e)	0.108±0.026(d)
3-Hydroxyfluorene(a,b,c)	0.420±0.018(d)	0.0384±0.0039(d)
2-Hydroxyfluorene(a,b,c)	0.854±0.015(d)	0.105±0.007(e)
4-Hydroxyphenanthrene(a,b,c)	0.0480±0.0045(d)	0.0102±0.0010(e)
9-Hydroxyphenanthrene(a,c)	0.959±0.061(d)	0.0114±0.0009(d)
3-Hydroxyphenanthrene(a,b,c)	0.123±0.007(d)	0.0271±0.0014(d)
1-Hydroxyphenanthrene(a,b,c)	0.133±0.014(e)	0.0479±0.0074(d)
2-Hydroxyphenanthrene(a,b,c)	0.0825±0.0007(e)	0.0242±0.0042(d)
1-Hydroxypyrene(a,b,c)	0.170±0.010(e)	0.0299±0.0018(d)

^(a)NIST GC/MS analysis

^(b)CDC GC/HRMS analysis; data were converted from ng/mL to μg/kg using the density of the urine (1.019 g/mL)

^(c)INSPQ GC/MS/MS analysis; data were converted from ng/mL to μg/kg using the density of the urine (1.019 g/mL)

^(d)The certified value is a weighted mean of average mass fractions, with one average from each of two or three analytical methods [30, 31]. The expanded uncertainty is the half-width of a symmetric 95 % parametric bootstrap confidence interval [32], which is consistent with the ISO Guide [33, 34]. The effective coverage factor, k, is 2

^(e)The certified mass fraction value is a weighted mean of the mass fractions from three analytical methods [30]. The uncertainty listed with each value is an expanded uncertainty about the mean [30, 31], with coverage factor k=2, calculated by combining within-method variances with a between-method variance [35] following the ISO Guide [33, 34]