Methylmercury determination in biological samples using electrothermal atomic absorption spectrometry after acid leaching extraction

Abstract

An efficient and sensitive method for the determination of methylmercury in biological samples was developed based on acid leaching extraction of methylmercury into toluene. Methylmercury in the organic phase was determined by electrothermal atomic absorption spectrometry (ETAAS). The methylmercury signal was enhanced and the reproducibility increased by formation of certain complexes and addition of Pd-DDC modifier. The complex of methylmercury with DDC produced the optimum analytical signal in terms of sensitivity and reproducibility compared to complexes with dithizone, cysteine, 1,10-phenanthroline, and diethyldithiocarbamate. Method performance was optimized by modifying parameters such as temperature of mineralization, atomization, and gas flow rate. The limit of detection for methylmercury determination was 0.015 mug g(-1) and the RSD of the whole procedure was 12% for human teeth samples (n=5) and 15.8% for hair samples (n=5). The method's accuracy was investigated by using NIES-13 and by spiking the samples with different amounts of methylmercury. The results were in good agreement with the certified values and the recoveries were 88-95%.

Assessment of matrix-dependent analyte stability and volatility during open-vessel sample dissolution for arsenic, cadmium, mercury and selenium

“…In most attempts, Pd proved to be the most effective chemical stabilization alone [18–20] or as a mixed-modifier with magnesium nitrate [18, 19], potassium permanganate [21] and DDC [22], though silver nitrate (AgNO 3 ) and potassium permanganate (KMnO 4 ) also afforded accurate determinations in fast-furnace programs without Pd [23]. Calcium nitrate was reported to be suitable for stabilization of As [15, 16, 20] and boron (B) [25] during atomization from graphite platforms.…”

Net Analyte Signal Standard Additions Method for Simultaneous Determination of Sulfamethoxazole and Trimethoprim in Pharmaceutical Formulations and Biological Fluids

“…In order to study the reproducibility of the proposed method, some synthetic mixtures containing SMX and TMP have been analyzed several times (n=6) 20,21 . The results were shown in Table 3 with their confidence intervals.…”

Extractive Spectrophotometric Determination of Trace Hg (II) in Eye Drops and Ayurvedic Medicines Using Pyridine 2-Carboxaldehyde 2-Hydroxybenzoylhydrazone

“…Due to human activities major amount of mercury enters into the environment through chlor-alkali industries, plastic industries, electrical, paint and pharmaceutical industries 2,[24][25][26][27][28] . In addition, Mercury compounds are used as catalysts, fungicides, pesticides and also add mercury to the environment via the natural resources like water, food and igneous rocks, in particular granite for living organisms and additionally increases the danger of mercury exposure, even at trace levels 29,30 . The environmental contaminants such as Pb…”