Table 5.

Average Concentration (mg/kg) ± RSD of face powders using different acid digestion methods.

	Elements	Acid Digestion Methods
		A-1 (HNO3(aq) + H2O2(aq))@ 95 °C for 3 h	B-1 (HCl(aq) + HNO3(aq)@108 °C for 2 h	C-1 (HNO3(aq) + HCl(aq) + H2O2(aq)) @ 125 °C for 2 h
With Triton X-100	As	0.75 ± 2.75	0.66 ± 0.10	<LODAs**
	Cd	1.46 ± 1.03	1.39 ± 2.86	0.90 ± 1.79
	Cr	<LODCr*	<LODCr*	2.6594 ± 3.62
	Pb	10.79 ± 0.11	9.62 ± 1.22	10.28 ± 0.92
	Hg	0.06 ± 1.42	0.03 ± 3.11	0.07 ± 3.75
	Ni	93.09 ± 0.02	34.44 ± 1.46	93.55 ± 0.17
		A-2 (HNO3(aq) + H2O2(aq))	B-2 (HCl(aq) + HNO3(aq)	C-2 (HNO3(aq) + HCl(aq) H2O2(aq))
Without Triton X-100	As	0.68 ± 0.61	0.45 ± 0.28	<LODAs⁎⁎
	Cd	1.04 ± 3.09	0.64 ± 0.67	0.53 ± 2.98
	Cr	<LODCr*	<LODCr*	1.23 ± 0.03
	Pb	8.11 ± 2.31	8.62 ± 2.54	1.48 ± 0.03
	Hg	0.04 ± 3.69	0.04 ± 1.64	0.05 ± 0.03
	Ni	61.08 ± 0.43	21.77 ± 1.17	5.03 ± 0.05

^⁎LOD _Cr = 7.09 x 10⁻² mg/L.

^⁎⁎LOD _As = 1.99 x 10⁻⁴ mg/L.