SURFACES; WATER; LIBS; SERS; IMPROVEMENT; ABLATION; SAMPLES; SENSOR; FLUIDS

In this study, we developed a substrate to enhance the sensitivity of LIBS by 5 orders of magnitude. Using a combination of field enhancement due to the metal nanoparticles in the substrate, the aggregate effect of super-hydrophobic interfaces and magnetic confinement, we performed a quantitative measurement of copper in solution with concentrations on the ppt level. We also demonstrated that the substrate improves quantitative measurements by providing an opportunity for internal standardization.

SURFACTANT SENSORS; AQUEOUS-SOLUTIONS; SYSTEM; LIBS

Domestic detergents are widely used and the detection of detergent residues on tableware is closely related to people's health. As is known to all, it is difficult to sample and measure the residual detergent on tableware. The purpose of this paper is to explore a rapid in situ detergent residues detection method. We have using laser-induced breakdown spectroscopy (LIBS) measured the detergent on porcelain plate. Based on our previous research, we further studied the spectra of detergent in argon atmosphere, and compared them with that in air. We found the spectral characteristics of the cyanogroup (CN) were related to the air around the measuring point. It was indicated that CN could not as previously speculated be used as the LIBS detection feature of detergent. The improvement of signal-to-noise ratio (SNR) in argon environment was proved and we made a study of semi quantitative measurement by the peak height of 330.30 nm in argon atmosphere. An experiment measuring the detergent on tableware after washed was taken. It illustrated that the LIBS technology has promising potential applications for tableware cleaning process or food production process as a means of on-line detection.