Determination of Phosphorus in Soil by ICP-OES Using an Improved Standard Addition Method

Table 4

Concentrations of the calibration working standards used in ISAM.

Element	Volume of soil mixture solution (mL)	Concentration of stock calibration standards (mg/L)	Volume of stock calibration standards (µL)	Concentration of P in a series of calibration standard solutions (mg/L)
P	10	200	10	0.2
		200	25	0.5
		200	50	1.0
		500	30	1.5
		500	40	2.0
		500	60	3.0