Comparison of DMA-80 and ICP-MS Combined with Closed-Vessel Microwave Digestion for the Determination of Mercury in Coal

Abstract

As one of the most widely used techniques for concentration determination of trace elements in coal, inductively coupled plasma mass spectrometry (ICP-MS) has also been used in several studies for the determination of mercury concentration in coal. ICP-MS after closed-vessel microwave digestion and a Milestone DMA-80 are employed in this study to determine the mercury concentration in coal. Three NIST standard references of coal samples were selected as references to verify the accuracy of the test results. The Au rinse solution (200 μg/L, 5% HNO3) can diminish mercury memory effects to a blank level within 80 seconds. The results showed that ICP-MS can accurately determine the mercury content in mercury standard solutions, but the mercury concentration in most NIST samples after microwave digestion is lower than the detection level of the ICP-MS. The inaccuracy may be due to volatilization of mercury during solid sample digestion process. By contrast, the determined concentrations in NIST samples by the Milestone DMA-80 are very close to the verified values. Therefore, ICP-MS is not recommended to analyze mercury in coal after digestion even in a closed-vessel digestion system, but the mercury direct analyzer (without digestion) is recommended to analyze mercury in coal.

Method for determination of elemental impurities in metronidazole benzoate using inductively coupled plasma mass spectrometry

“…The high volatility and memory effect of mercury lead to incomplete recovery. 16,17 Therefore, HCl was added to the diluent to stabilize mercury in the solution, and gold was selected as the stabilizer to prevent the volatilization and loss of mercury. There are usually spectroscopic interference and non-spectroscopic interference in ICP-MS testing.…”

Determination of Total Mercury and Carbon in a National Baseline Study of Urban House Dust

“…One of the most commonly used techniques for quantifying total Hg in these media is acid digestion (e.g., aqua regia) followed by stannous chloride reduction and spectroscopic determination. Wet digestion methods must take steps to ensure that no Hg is lost throughout the process, and thus tend to be more labor intensive than the direct solid sample analysis [20]. Another challenge associated with wet digestion is the difficulty of dissolving low solubility Hg compounds, such as Hg sulfide [21].…”

“…Thermal decomposition with subsequent trapping by amalgamation, followed by atomic absorption spectrophotometry (e.g., US-EPA Method 7473), is another approach used to quantify Hg [22]. A key advantage of this method is that the sample pre-treatment is limited to drying and sieving, which provides a fast turn-around time [20]. To investigate the above-mentioned affinity of Hg for organic carbon, a method is also needed to determine the carbon content of house dust.…”

Design and Characterization of Electrochemical Sensor for the Determination of Mercury(II) Ion in Real Samples Based upon a New Schiff Base Derivative as an Ionophore

“…Among the different valence states, Hg (II) is the most toxic even when present in very trace amounts [ 1 ]. Mercury can enter and accumulate in the human body through the food chain causing severe health problems such as vital organ damage, nervous system impairment, kidney failure, and cancer [ 2 , 3 , 4 , 5 ]. Thus, monitoring trace concentrations of this toxic element has become a vital necessity.…”

“…Many organic and inorganic compounds have been documented in the literature as ionophores for the synthesis of ion selective electrodes for the determination of Hg 2+ ion in various samples over the last three decades. Crown ether derivatives [19,20], polyvinyl pyridine [21], calix [4]pyrrole amide derivative [22], calixarene derivatives [23][24][25][26][27][28], thiol functionalized ionic liquid [29], amines [30,31], thioureas [25,32], and dithio derivatives [33,34] have all been used as ionophores for designing ISEs of Hg 2+ ions. It's worth mentioning that, some ionic liquids, e.g., 1-n-butyl-3-methylimidazolium tetrafluoroborate (BMIMBF 4 ) [35], polypyrrole (PPy) [36], O,O -(2,2 -biphenylene)dithiophosphatepentyl (PenDTF) [37], 1methyl-2-butylthioimidazolium combined with bis(trifluoromethanesulphonyl) imide [29], dimethylglyoxime [38], and 2-mercaptobenzimidazol (2MBI) [39] are widely employed as ionophores in ISEs of Hg(II) ions.…”