Speciation of mercury in various samples from the micro-ecosystem of East Lake by hollow fiber-liquid–liquid–liquid microextraction-HPLC-ICP-MS

Abstract

A novel method by combining hollow fiber-liquid-liquid-liquid microextraction (HF-LLLME) with HPLC-ICP-MS was developed for the speciation of inorganic mercury (Hg 2+ ) and organomercury including methylmercury (MeHg + ), ethylmercury (EtHg + ) and phenylmercury (PhHg + ), in the microecosystem of East Lake (Wuhan, China). The factors affecting HF-LLLME were systematically investigated.Under the optimized conditions, the limits of detection for four mercury species were in the range of 2.9-5.6 ng L À1 with the relative standard deviations (c ¼ 0.5 mg L À1 , n ¼ 7) ranging from 5.6 to 10.6%. The developed method was validated by analyzing a certified reference material of DORM-2, and the determined values were in good agreement with the certified values. The method has been applied for the speciation of mercury in five representative samples from the micro-ecosystem of East Lake including atmospheric particles, lake water, fish, plant and sediment.

Methods and recent advances in speciation analysis of mercury chemical species in environmental samples: a review

“…In the work of Chen et al [10] the application of HF-LLLME for enrichment of Hg 2+ , MeHg, EtHg, and PhHg in lake water and sediment samples was reported. In the method, using PAN as a chelating agent, the analytes were transferred to acceptor phase (Na 2 S 2 O 3 solution) using toluene as an extraction solvent and injected to HPLC-ICP-MS for subsequent analysis.…”

“…However, long extraction time and memory effect when reusing the hollow fiber could be stated as its shortcomings. The technique has been employed with HPLC-ICP-MS [10,62] and CE-UV [11,37] analysis techniques in Hg speciation analysis.…”

“…In LC separation techniques, CV-AAS, [9,39] HG-AAS, [74] CV-AFS, [15,38,43] HG-AFS, [44] CV/ HG-AFS, [28] PJDA-AFS, [27] ICP-MS, [8,10,12,[24][25][26]62,74] and DAD [18,56] detectors have been used. GC has been hyphenated to CV-AFS, [76] pyro-AFS, [73,75] MS, [75] TOF-MS, [78] ICP-MS, [20,21,73,75] and FID [45] detectors.…”

“…Since the concentration of Hg in environmental samples might be at trace level, the Hg speciation analysis requires the sample pre-treatment and pre-concentration methods such as SPE, [8] SPME, [9] HF-LLLME, [10,11] DLLME, [12][13][14][15][16] SDME, [17,18] CPE, [19] and P&T. [20][21][22][23] Separation and determination techniques including LC, GC, and CE coupled to ICP-MS, [3,10,12,[24][25][26] PJD-AFS, [27] AFS (HG/CV-AFS), [9,28] and CV-AAS [9] have been used. As well, particular attention has to be paid to the sampling, transportation, and proper sample storage procedures.…”

“…A technique in which analytes are extracted to a liquid membrane sustained in the pores of hollow fiber and then to an acceptor solution, [61] has been used as another pre-concentration option in speciation analysis of Hg. [10,11,37,62] HF-LPME is simple and inexpensive technique which provides excellent analyte pre-concentration and sample cleanup. However, long extraction time and memory effect when reusing the hollow fiber could be stated as its shortcomings.…”