Table 1.
Operating parameters for REE determination using ICP-OES and ICP-MS.
Fig 1.
Schematic representation of preconcentration and detection of REEs from a complicated matrix using LLE-ICP-OES.
Fig 2.
Extraction percentage of REEs as a function of nitric acid concentration in aqueous solution.
Concentration of each REE: 200 ng mL-1; TODGA: 0.025 M; extraction time: 2 min each time; extraction frequency: three times.
Fig 3.
Extraction percentage of REEs as a function of TODGA concentration in the organic phase.
Concentration of each REE: 200 ng mL-1; concentration of HNO3: 3 M; extraction time: 2 min each time; extraction frequency: three times.
Fig 4.
Extraction percentage of REEs as a function of coexisting ion concentration in the aqueous phase.
Concentration of each REE: 200 ng mL-1; concentration of HNO3: 3 M; extraction time: 2min each time; extraction frequency: three times; (10n = Ccoexisting ion/CREE, n = 3, 4, 5).
Fig 5.
Recovery of REEs as a function of EDTA concentration in the aqueous phase.
Concentration of each REE: 200 ng mL-1; concentration of HNO3: 3 M; extraction time: 2 min; back extraction: 0.03 M EDTA with a stripping time of 3 min.
Table 2.
Analytical characteristics of LLE-ICP-OES method for the determination of the target ions.
Table 3.
Comparison of the proposed LLE-ICP-OES procedure with other analytical methods.
Table 4.
Comparison of the recovery of tap water samples spiked with different concentrations of REEs using the proposed LLE-ICP-OES method and the ICP-MS reference method.