Simultaneous Determination of Available Phosphorus and Available Sulfur in Calcareous Soil by ICP-AES

The soil sample (5.00 g) was added into 50.0 mL of 0.5 mol·L^-1 NaHCO₃ solution and was extracted by oscillation at 20-25℃ for 30 min. After the solution was filtered with medium-speed quantitative filter paper, 5 mL of 1.0 mol·L^-1 HCl solution was added in to 5.0 mL of the filter solution. The available phosphorus and available sulfur in the solution were determined by ICP-AES at P 214.914 nm and S 182.034 nm, respectively. Linear relationship were found between the emission intensity and the mass concentration of phosphorus and sulfur within 10.0 mg·L^-1, with detection limit (3s) of 0.15, 0.29 mg·kg^-1 for available phosphorus and available sulfur respectively. Recovery rates obtained by standard addition method were in the range of 95.2%-107%, and RSDs (n=12) were in the range of 2.0%-3.6%. The poposed method was used to determined available phosphorus and available sulfur in calcareous soil, giving results in agreenment with those obtained by forestry standard method.