Synthesis and Characterization of Feed-Grade Monocalcium Phosphate Ca(H₂PO₄)₂·H₂O from Oyster Shell

Table 1

Upper limits for the As, Pb, and Cd contents in the solid samples derived from the LOD in the solutions.

Sample	Content of heavy elements (ppm)
	As (188.979 nm)	As (193.696 nm)	Pb (217.000 nm)	Pb (220.353 nm)	Cd (214.440 nm)	Cd (228.802 nm)
LOD, mg/L^(a)	0.0217	0.0319	0.0064	0.0293	0.0016	0.0020
Oyster shell	<21.9	<32.3	<6.5	<29.7	<1.6	<2.0
PCC	<21.7	<31.9	<6.4	<29.3	<1.6	<2.0
MCP	<21.7	<32.0	<6.4	<29.3	<1.6	<2.0

^(a)The LOD in the measured solutions is evaluated from the standard deviation (σ) of the blank measurements, LOD = 3 × σ.