. Author manuscript; available in PMC: 2022 Oct 5.

Published in final edited form as: Environ Sci Technol. 2021 Sep 16;55(19):13113–13121. doi: 10.1021/acs.est.1c00937

Table 4:

Statistical parameters from the Passing Bablok analysis of XRF and ICP-MS measurements. Results are the parameters of the equation y = a + bx, where x is the ICP-MS measurement and y is the XRF measurement expressed as median and 95% confidence interval (CI).

Element	a median (95% CI)	b median (95% CI)
Ni	−6.51 (−4.23, −9.56)	1.00 (0.985, 1.02)
Zn	−5.89 (−0.943, −9.22)	0.980 (0.930, 1.02)
Se ^*	−0.029 (−0.045, 0.00)	0.928 (0.878, 0.945)
As	−0.057 (−0.227, 0.00)	0.253 (0.037, 0.614)
Pb	−0.160 (−0.092, −0.216)	0.962 (0.919, 1.00)

For concentrations less than 2 mg/kg (n = 80): a = −0.003 (−0.029, 0.013), b = 0.835 (0.694, 0.916). For concentrations greater than 2 mg/kg (n = 17): a = −0.682 (−1.73, 0.151), b = 0.980 (0.933, 1.02).