High-sensitive and rapid determination of cadmium concentration in water with laser-induced breakdown spectroscopy

To realize high-sensitive and rapid analysis of trace cadmium in water, an unpolluted thin wood slice was chosen as substrate to absorb water sample and then analyzed with laser-induced breakdown spectroscopy(LIBS) after being dried, which overcomes the drawbacks of low sensitivity and reproducibility existing in the process of direct analysis of water sample with LIBS. The 214.44 nm ionic line of cadmium was chosen as analytical line. A calibration curve was established for the purpose of quantitative analysis. The limit of detection of cadmium in water was determined to be 55 μg/L and the relative standard deviation of signal in different measurements was less than 5%. The time needed for each measurement was less than 5 min.