The Development of a Rapid, Cost-Effective, and Green Analytical Method for Mercury Speciation

Toxics. 2024 Jun 11;12(6):424. doi: 10.3390/toxics12060424.

Abstract

Mercury is a naturally occurring metal found in various inorganic and organic forms within the environment. Due to its high toxicity, there is global concern regarding human exposure to this element. The combination of high-performance liquid chromatography and inductively coupled plasma mass spectrometry (HPLC-ICP-MS) is commonly used to analyze the different forms of mercury in a sample due to its high sensitivity and ability to selectively detect mercury. However, the traditional HPLC-ICP-MS methods are often criticized for their lengthy analysis times. In this study, we have refined the conventional approach by transitioning to ultra-high performance liquid chromatography coupled with inductively coupled plasma mass spectrometry (UHPLC-ICP-MS). This modification has resulted in significant reductions in runtime as well as reagent and argon usage, thereby offering a more rapid, environmentally friendly, and cost-effective method. We successfully adapted an HPLC-ICP-MS method to UHPLC-ICP-MS, achieving the analysis of Hg2+ and MeHg+ within 1 min with a mobile phase consumption of only 0.5 mL and a sample volume of 5.0 µL; this is a major advance compared to HPLC analysis with run times generally between 5 and 10 min. The method's performance was assessed by analyzing muscle and liver tissue samples (serving as reference material) from fish, demonstrating the versatility of the method in relation to different complex matrices.

Keywords: ICP-MS; UHPLC-ICP-MS; environmental monitoring; fast method; mercury speciation.

Grants and funding

The project was supported by the São Paulo Research Foundation (FAPESP grants number 2016/10060-9 and 2014/05151-0) and the fellowships by the Brazilian Federal Agency for Support and Evaluation of Graduate Education (CAPES financial code 001).