Simple and sensitive method for the determination of methylmercury in hair using thin-layer chromatography with thermal decomposition gold amalgamation atomic absorption spectrophotometry

Abstract

An improved method is described for the determination of methylmercury (MeHg) in human hair that is based on thin-layer chromatography and thermal decomposition gold amalgamation atomic absorption spectrophotometry. The dithizone extraction and application procedure of this technique were optimized, thus improving its sensitivity and robustness and enabling the use of less-toxic solvents than other approaches. The limit of detection was 0.18 ng MeHg (as Hg), corresponding to 0.018 mg MeHg kg -1 of hair relative to a 10 mg sample. This method is appropriate for detecting MeHg in hair at the approximate reference dose level established by the United States Environmental Protection Agency.

Atomic spectrometry update: review of advances in elemental speciation

“…It is unusual to see TLC used in conjunction with atomic spectrometry but this has been undertaken by Haraguchi et al to quantify MeHg in hair. 93 The MeHg was extracted using 2.2 mol L −1 HCl and heating at 100 °C for five minutes, neutralisation with 2 mol L −1 NaOH and back extraction into 0.01% (w/v) dithizone in toluene. The toluene layer was removed and added to 2 mL of 1 mol L −1 NH 3 , the mixture shaken and then centrifuged, the toluene layer removed and evaporated and the residue redissolved in acetone and this was applied to a TLC plate with n -hexane : acetone (9 : 1, v/v) used as the developing solvent.…”

Validasi Metoda Pengujian Metil Merkuri (Me-Hg) dalam Matrik Biomarker Rambut Manusia Menggunakan Kromatografi Gas Electron Capture Detector (GC-ECD)

“…Meski banyak pilihan metode analisis untuk pengujian Me-Hg, kajian ini dilakukan menggunakan kromatografi gas ECD (Haraguchi et al, 2022;Haraguchi et al, 2020;Puk & Weber, 1994). ECD beroperasi sesuai dengan prinsip penyerapan fase gas elektron bebas dengan molekul penangkap elektron.…”