Nanyang Technological University, Singapore
Title: The use of tetrathiafulvalene to improve mercury determination in air borne particulate matter
Biography: Budanovic Maja
Recent studies emphasizing the harmful effect of mercury (Hg) on the environment have increased the demand for low level mercury analysis towards improvement of global Hg pollution control. Multi-elemental inductively coupled plasma mass spectrometry (ICP-MS) determination of Hg can lack accuracy due to low stability of Hg ions in solutions that are susceptible to adsorption/volatilization with negative or positive bias. In this study, sampling and analysis of airborne Hg in Singapore was carried out using our recently developed ICP-MS method. The determined mercury levels were compared against the pollutant standards index (PSI) from 17 October to 17 November 2018, during which the air quality in west Singapore showed small oscillations from 22-66 and good/moderate conditions. We observed an improvement in accuracy for mercury determination of up to 10 times along with proven selectivity of the method evident due to little to no lithium tetrathiafulvalene carboxylate (LiCTTF) influence on other trace elements (Figure 1). Improved stabilisation of mercury ions resulted in higher precision for ICP-MS measurements with RSD ranging from 1.07 to 4.36. Statistical analysis demonstrated the preservation ability of 10 g mL-1 LiCTTF for both microwave digestion procedure and for external calibration using multi-elemental standard solutions with t-values of <1.5. The results obtained in this study emphasize the utility of LiCTTF in ICP-MS determination of mercury to prevent mercury losses, especially for the low-level mercury analysis required for environmental mercury pollution trend assessment.