Laser-induced breakdown spectroscopy (LIBS) is one of the competitive approaches for monitoring water quality due to its attractive features, such as rapid, simultaneous multi-element detection, and in situ, real-time analysis capabilities. However, the detection sensitivity of LIBS is still unsatisfactory when directly analyzing liquid samples because it suffers from several problems, e.g., water splashing, surface ripples, and quenching of intensity. Therefore, it is meaningful to find a method to solve these above problems and improve the detection sensitivity of trace heavy metal element in aqueous solution analysis.

The researchers of the laser advanced manufacturing groups in WNLO proposed a method of chemical replacement combined with surface-enhanced laser-induced breakdown spectroscopy (CR-SENLIBS) for analyzing liquid samples. Chemical replacement was applied as an automatic, simple, and rapid pretreatment method to convert the heavy metal cations in aqueous solution on magnesium alloy surface. The results demonstrate that the CR-SENLIBS is a feasible method for improving the detection sensitivity of trace heavy metal elements in the liquid sample.

This research has been financially supported by the National Special Fund for the Development of Major Research Equipments and Instruments (No. 2011YQ160017), by the National Natural Science Foundation of China (No. 51429501, 61575073, and 61378031), by Fundamental Research Funds for the Central Universities of China (HUST: 2015TS075), which has been published on the journal of Optics Express (Vol. 24, Issue 12, pp. 13410-13417, 2016)

Figure 1. Schematic diagram of the sample pretreatment procedures (a) and the experimental setup (b).

Figure 2. Calibration line of Cr