Errata

There were minor errors made in the December 2007 article, “Uncertainty Determination for Nondestructive Chemical Analytical Methods Using Field Data and Application to XRF Analysis for Lead,” by Bartley et al.

Table I below shows correct placement of the “Bootstrap” and “ISO GUM” headings.

TABLE I Accuracy After Bias Correction of XRF Pb Method for _n Data Points Between 10 μg and 300 μg in Comparison with ICP Method with Assumed RSD_ref = 5%

				Bootstrap		ISO GUM
Sampler	N	Bias	Outliers	Â	A 95	Â	A 95
				(%)	(%)	(%)	(%)
GSP	83	–0.077	0	23.1	27.4	20.5	25.1
CFC	70	–0.006	0	24.6	29.8	29.8	31.8
25-mm	57	–0.062	1	26.0	33.5	33.1	37.6
Button	68	–0.089	2	21.0	30.1	24.0	26.5
IOM	58	0.00	1	34.2	44.0	39.7	43.3
Note: The ISO GUM approach to estimated uncertainty, reduced by observed outliers, is presented together with comparable bootstrap estimates.

In the Discussion section, p. 939, the sentence

“However, for comparison, the European Community has adopted⁽¹⁹⁾ a 30% value for a similar overall uncertainty that does not include evaluation uncertainty.”

should read:

“However, for comparison, the European Community has adopted⁽¹⁹⁾ a 30% value for a similar expanded uncertainty.”

In Appendix A, Eq. A6 should read:

In Appendix B, before Eq. B2, “the estimate A_f ” should read simply “A_f ”. After Eq. B9, insert “where u= û”.

In Appendix C, after Eq. C1 in Step 8, “the sixth point” should read “the fifth point”.