Preconcentration of nickel and cadmium by TiO2 nanotubes as solid-phase extraction adsorbents coupled with flame atomic absorption spectrometry

TiO2 nanotubes, a new nanomaterial, are often used in the photocatalysis. Due to its relatively large specific surface areas it should have a higher enrichment capacity. However, very few applications in the enrichment of pollutants were found. This paper described a new procedure to investigate the trapping power of TiO2 nanotubes with cadmium and nickel in water samples as the model analytes and flame atomic absorption spectrometry for the analysis. The possible parameters influencing the enrichment were optimized. Under the optimal SPE conditions, the method detection limits and precisions (R.S.D., n = 6) were 0.25 ng mL−1 and 2.2% for cadmium, 1 ng mL−1 and 2.6% for nickel, respectively. The established method has been successfully applied to analyze four realworld water samples, and satisfactory results were obtained. The spiked recoveries were in the range of 90.2–99.2% for them. All these indicated that TiO2 nanotubes had great potential in environmental field.