Table 1.

Bulk composition (μg g⁻¹) with standard deviation (n = 5) and limit of detection (LOD) obtained from solution based ICP-MS analysis of powdered shells.

	White shell		Pink shell		Brown shell		LOD
	mean	SD	mean	SD	mean	SD
Mg	92.8	1.3	76.9	0.8	106.8	0.9	0.17
K	1001	4	1189	6	1856	5	9.8
Ti	<LOD		<LOD		0.91	0.11	0.46
V	0.05	0.04	0.054	0.006	0.97	0.05	0.054
Mn	24.5	0.5	24.1	0.6	178	4	0.080
Fe	8.2	0.4	10.6	0.4	4766	9	0.22
Co	0.164	0.021	0.099	0.009	1.225	0.018	0.003
Ni	0.55	0.09	2.2	0.3	2.56	0.25	0.37
Cu	1.27	0.04	1.84	0.10	17.4	0.3	0.11
Zn	16.6	0.3	16.3	0.6	90.1	2.8	0.60
Sr	10134	6	947	9	10678	9	0.012
Ag	<LOD		<LOD		<LOD		0.036
Cd	0.24	0.11	0.30	0.09	0.54	0.17	0.17
Ba	1.74	0.11	1.90	0.07	8.4	0.4	0.080
Pb	0.78	0.04	0.69	0.06	3.56	0.08	0.030