Table 1: Determination of Hf(IV) ion in spiked four water samples.


 Sample Hf(IV) added (ng cm−3) Hf(IV) found (ng cm−3) RSD (%) Recovery (%)
Proposed ICP-AES

 Tap sample 0.00 NDa NDa
40.0 41.5 39.1 1.2 103.75
80.0 78.6 81.5 1.6 98.25
 Mineral water 0.00 NDa NDa
60.0 60.5 58.7 1.2 100.83
120 118.7 121.1 1.8 98.92
 River water 0.00 NDa NDa
50.0 49.2 50.6 1.1 98.40
100 101.2 102.2 1.4 101.20
 Waste water 0.00 NDa NDa
70.0 69.6 71.4 1.3 99.43
140 141.0 138.3 1.7 100.71

aNot detected.