Determination Of Silver In Geological Samples Using Aerosol Dilution ICP-MS After Water-Bath Extraction With Inverse Aqua Regia

A valid method for trace silver (Ag) detection in geological samples was developed in this study using aerosol dilution inductively coupled plasma-mass spectrometry after extraction with inverse aqua regia. This was proposed primarily to reduce the interference from Nb and Zr during mass spectrometric measurements. Almost 93% of Nb and Zr was removed after the extraction. By mixing an appropriate amount of Ar with the sample aerosol using an aerosol dilution system prior to plasma, the residual Nb oxides and Zr oxides or hydroxides could be successfully removed. The relative yields of the interfering oxides and hydroxides were as low as 0.087% (NbO/Nb) and 0.013% (ZrOH/Zr), which were 3–5 times lower than those in the traditional mode without the addition of Ar. Moreover, the signal-to-noise ratio of Ag was five times higher than that in the traditional mode. The proposed method was applied to the determination of Ag in 68 standard reference materials (SRMs) of soil, sediment, and rock. The results for 47 of these geological SRMs were in good agreement with the reference values. The Ag levels in three SRMs (GSP-2 Granodiorite, STM-2, and SGR-1b) are being reported for the first time herein. For these SRMs, 10 separate aliquots of the sample were digested and analyzed over a period of three months, and analysis revealed that the determined values were reasonable. Thus, the proposed method shows significant potential for the accurate determination of trace Ag in various geological samples.

Simultaneous Or Sequential Multi-Element Graphite Furnace Atomic Absorption Spectrometry Techniques: Advances Within The Last 20 Years

Electrothermal or graphite furnace atomic absorption spectrometry (ETAAS or GFAAS) is one of the most widely used techniques for determining elements in different matrices (e.g., foodstuffs, pharmaceuticals, biological specimens, nanomaterials, polymers, fuels and environmental media). Numerous elements can be simply and quickly determined with high precision and accuracy, low detection limits, and at moderate cost. The technique is also suitable for direct solid and slurry sample analysis. A crucial feature of this technique is that it can perform simultaneous or sequential multi-element analysis. Over the years, many instruments have come on the market for multi-elemental analysis using mostly line source (LS) GFAAS and high-resolution continuum source (HR-CS) GFAAS. This review covers publications from 2000 to 2020related to the simultaneous or sequential multi-elemental analysis by LS-GFAAS and HR-CS-GFAAS. Mainly the applications, the limits of detection, the use of internal standardization and other aspects regarding the matrix, pyrolysis and atomization temperatures and modifiers are discussed. Finally, a critical comparison is made between the LS-GFAAS and HR-CS-GFAAS techniques.

Continuous On-Line Leaching To Evaluate The Effect Of Toasting On Bioaccessibility, And Pb Source Apportionment Of Alternative Breads

Laser-induced with the increasing popularity of alternative breads, investigating their health benefits and risks is vitally important. The bioaccessibility of potentially toxic elements in these breads could indicate a potential risk to consumers. The continuous online leaching method (COLM) involves the sequential leaching of a mini-column of food by artificial saliva, gastric juice, and intestinal fluid with real time monitoring of elements being released. Because the dissolution equilibrium is shifted to the right from continuous exposure to fresh reagent, it assesses bioaccessibility in three gastrointestinal matrices in less than 30 min and includes valuable kinetic extraction information. In this study, a gluten-free (GF) and a rye bread were analyzed for As, Cd, and Pb before and after toasting. Toasting lowered all PTE concentrations by a factor of 1.5 (As in rye bread) to 2.5 (Cd in rye bread). Most of the PTEs present were bioaccessible whether the bread was toasted or not. In the case of As, a significant portion is in the form of As(III) and As(V). COLM analysis allowed for Pb sourcing, revealing two potential sources of Pb being released separately in gastric juice from rye bread based on their significantly different 206Pb/207Pb and 208Pb/206Pb isotope ratios. Comparison with Pb ratios reported in previous literature revealed that some of the gastric-mobile Pb in rye bread came from the Pb historically added to gasoline in North America. This source completely vanished upon toasting rye bread.

Archaeometallomics as a Tool for Studying Ancient Ceramics

In this paper, the concept of archaeometallomics is put forward to study the role of metal elements in cultural relics. An example is the influence of metal elements in the identification of their origin, dating, authenticity and the technology used for the production of ancient ceramics. This analysis also provides the social and cultural connotations of the development process of that time and shows that there is a close relationship between the rich glaze varieties and the metal elements in porcelain. The application of different analytical techniques in studying metallic elements in ancient ceramics is also briefly summarized. The construction of a metal element composition database and the related questions in the glaze color-forming mechanism of ancient relics should be considered an important research direction for future works.