Heavy metal galvanic displacement reaction on micrometer particles to assist LIBS for cu and Cr in liquids analysis with sub μg/L sensitivity

Abstract

Due to the severe threat posed by heavy metals to human health, relevant authoritative standards impose strict limits on the concentration of metal elements in water bodies, with the allowed minimum concentration of these elements reaching the μg/L level. Therefore, there is an urgent need to develop detection technologies for rapid, multi-element qualitative and quantitative analysis of heavy metal elements in water bodies at the μg/L level, especially in fields such as water quality monitoring or discharge control. This paper proposes a novel approach that combines a micron-sized particle galvanic displacement reaction with Laser-Induced Breakdown Spectroscopy analysis, referred to as the GDMP-LIBS method. This method can quickly complete the preparation of the micro-particle layer and the displacement reaction of heavy metal elements. By using the developed experimental procedure and optimized experimental parameters, the spectral signals obtained by this method show significant enhancement. For the detection of Cu and Cr, the detection limits are below 1 μg/L, with sensitivity greater than other LIBS methods, and the limits of detection (LoDs) are reduced by several orders of magnitude, even lower than the lowest allowed concentration in relevant authoritative water quality standards by at least one order of magnitude. In the low concentration range from a few μg/L to several tens of μg/L, the quantitative analysis error of this method is small. Overall, as a highly sensitive, rapid, multi-element, and easy-to-operate method for detecting heavy metals in water, the GDMP-LIBS method has the potential for widespread application in the field of heavy metal water quality detection.