DNA binding in combination with capillary electrophoresis and inductively coupled plasma mass spectrometry for the rapid speciation analysis of mercury

Abstract

We herein developed a method for the rapid speciation analysis of Hg 2+ and CH 3 Hg + by using specific DNA sequences to bind Hg 2+ and CH 3 Hg + together with capillary electrophoresis and inductively coupled plasma mass spectrometry. The specific DNA sequences can combine with Hg 2+ and CH 3 Hg + with different binding force, which makes the formed DNA-Hg 2+ and DNA-CH 3 Hg + conjugates possess different negative charges, and thus make Hg 2+ and CH 3 Hg + can be more easily and rapidly separated by capillary electrophoresis under reverse mode. Under the optimal conditions, the Hg 2+ and CH 3 Hg + can be baseline separated and detected by capillary electrophoresis-inductively coupled plasma mass spectrometry within 11 min with a detection limit of 0.12 and 0.10 ng/mL, respectively. With the help of the method, we have successfully determined Hg 2+ and CH 3 Hg + in dried fish muscle samples with a recovery of 95-101% and a relative standard deviation (n = 6) <5%. In comparison with previous capillary electrophoresis and inductively coupled plasma mass spectrometry methods, the proposed method has shorter separation time and higher sensitivity under the same conditions of inductively coupled plasma mass spectrometry. Higher sensitivity and shorter separation time make our method a valuable technique to the speciation analysis of trace Hg 2+ and CH 3 Hg + in the environmental and food samples.

Flow-Injection Analysis (FIA) Electrochemical Speciation of Copper in Coastal Waters by Anodic Stripping Voltammetry (ASV)

“…To the present, several analytical methods have been reported for the determination of Cu, such as atomic absorption spectroscopy (Elci, Kabakcı, and Elci 2015), inductively coupled plasmaatomic emission spectrometry (Dahlquist and Knoll 1978;de Chanvalon et al 2016), inductively coupled plasmamass spectrometry (ICP-MS) (Ghaedi, Ahmadi, and Shokrollahi 2007;Kuznetsova, Bychkova, and Timerbaev 2020), capillary electrophoresis (CE) (Chen et al 2016;Lara et al 2016), liquid chromatography (LC) (Hu et al 2003;Sun et al 2015), and anodic stripping voltammetry (ASV) (Ting et al 2015;Wan et al 2015;Chaiyo et al 2016). The primary methods used for speciation analysis are LC (B'hymer and Caruso 2004;Gao and Ma 2011), CE (Chen et al 2018;Michalke and Vinkovi c-Vr cek 2018;Michalke, Willkommen, and Venkataramani 2019), and ASV (Laglera and Monticelli 2017;Liu et al 2017;Han et al 2018;Hu et al 2019). However, LC and CE suffer from disadvantages such as complex pretreatment, slow analysis, and high cost.…”