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A direct solid sampling method was developed for determining mercury in bioresorbable calcium phosphate-based materials by electrothermal vaporization (ETV) coupled to an inductively coupled plasma mass spectrometry (ICP-MS) instrument. The ETV system is based on fast sample heating using a halogen lamp enclosed in a glass chamber. The heating program comprises only a vaporization step (10 s) followed by a cooling step (120 s) when a solid sample was analyzed. An additional step of 20 s at 80 °C was necessary when aqueous solutions were used for calibration. Mercury was vaporized at a relatively low temperature (650 °C) without co-vaporizing the main matrix (more than 95% of the matrix remains in the lamp dimpled cavity). External calibration with aqueous reference solutions deposited on the sample residue was used for Hg quantification. The accuracy of the proposed method was evaluated by certified reference material analysis (MESS-3) and by pneumatic nebulization ICP-MS (NEB-ICP-MS), and no statistical difference was observed between the results. Relatively high masses (up to 10 mg) can be analyzed without interferences. The limit of quantification (0.2 ng g−1) by ETV-ICP-MS was lower than that by NEB-ICP-MS (60 ng g−1), the precision was better than 15% and the sample throughput was 20 per hour. Therefore, the proposed low-cost ETV system is attractive for determining Hg at the ultra-trace level in biomaterials and can be used for routine analyses. [ABSTRACT FROM AUTHOR]

Here, we use vertebral microchemistry to investigate the habitat use patterns of the longnose stingray Hypanus guttatus in the northern and northeastern regions of Brazil, and to evaluate the existence of potential nurseries of the species. Samples were collected in Maranhão, Rio Grande do Norte and Pernambuco states between 2008 and 2019. Trace element concentrations of Ba:Ca, Mg:Ca, Mn:Ca and Sr:Ca in vertebrae were determined through laser ablation inductively coupled plasma mass spectrometry. We used one‐step permutational ANOVAs to evaluate multi and single‐element differences in element:Ca ratios among life stages and sexes across and within sites. Element signatures differed among all sites for both single and multi‐element settings. However, there were few differences among life stages within sites, except for Mn:Ca between life stages for Maranhão state, and between sexes for Sr:Ca for both Pernambuco and Rio Grande do Norte, and Ba:Ca for Rio Grande do Norte. Furthermore, all multi and single‐element analyses across locations were significant and highlight the strong differences by sites. We also performed a nonmetric multidimensional scaling analysis, which demonstrated the strong differences for samples from Rio Grande do Norte and the other two sites. By analysing the lifetime transects of each sample, we observed that there was little variation in all element:Ca ratios within sites. Therefore, we argue that the longnose stingray likely does not display extensive habitat use shifts and fulfils much of its life cycle within each area. Finally, we obtained no evidence of nurseries for any site and suggest this is likely a pattern across the species distribution. Future studies investigating habitat use with samples from larger specimens (disc width > 90 cm, >15 years) are needed to better understand the species habitat use patterns across all size ranges. [ABSTRACT FROM AUTHOR]

The present review deals with microwave-induced plasma optical emission spectrometry (MIP OES) with focus on MIP sustained by N2. Advances of MIP OES as an analytical tool and N2-MIP OES application in elemental analysis are highlighted. The novel microwave inductively coupled atmospheric-pressure plasma (MICAP) is also presented and the N2-MICAP is discussed. The assertion of MIP OES as an atomic spectrometry technique for elemental analysis occurred mainly due to the development of N2-MIP generated in a cavity embedded in a narrow width waveguide. The precise location of the cavity as a function of the wavelength associated with the 2450 MHz frequency maximizes the magnetic field and generates H-type excitation almost entirely, and is similar to that occurring in argon inductively coupled plasma (Ar-ICP). Microwave induced plasma optical emission spectrometry based on the use of N2-MIP is in general more sensitive in terms of detection limit than the flame atomic absorption spectrometry (FAAS) and almost comparable to inductively coupled plasma optical emission spectrometry (ICP OES). Since the introduction of a commercial N2-MIP OES instrument in the last decade, which allows metals and non-metal determination, applications of the technique for the analysis of samples with different matrices have increased as demonstrated in the present review. [ABSTRACT FROM AUTHOR]

In this work, a method for the determination of As, Sb, Se and Te in mineral coal was developed using solid sampling electrothermal vaporization inductively coupled plasma mass spectrometry (SS-ETV-ICP-MS). The following operational parameters of the ETV-ICP-MS system were evaluated: the furnace temperature program, the mass of Ir used as the modifier, the oxygen flow rate (used in the pyrolysis step) and carrier and bypass gas flow rates. The possibility of using calibration with aqueous standard solutions was also investigated. Calibration using aqueous standard solutions was feasible for As, Sb and Te determination, and calibration using certified reference materials (CRMs) of coal was required for Se determination. For comparison of the results, coal samples were decomposed by microwave-assisted wet digestion to obtain reference values for As and Sb by ICP-MS and Se by collision/reaction cell technology inductively coupled plasma mass spectrometry (CRC-ICP-MS). In addition, samples were digested by microwave-induced combustion to obtain reference values for Te by ICP-MS. No statistical difference was observed between the results by SS-ETV-ICP-MS and those obtained by ICP-MS (As, Sb and Te) or CRC-ICP-MS (Se) after sample digestion. Additionally, CRMs of coal (NIST 1632b, NIST 1632c and NIST 1635) were analysed by SS-ETV-ICP-MS, and the results were in agreement with the certified values. The limit of quantification was 0.03, 0.01, 0.03 and 0.006 μg g−1 for As, Sb, Se and Te, respectively. These values were lower than those obtained by other methods and allowed the determination of analytes at trace and ultra-trace levels. The SS-ETV-ICP-MS method for coal presented other advantages, such as minimization of the sample preparation step, minimization of the use of large amounts of reagents and suitability of accurate determination of those analytes commonly susceptible to limitations using conventional methods. [ABSTRACT FROM AUTHOR]

Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) has received significant attention over the last 10 years and has been widely used for the analysis of biological samples. The technique allows the determination of elements and isotopes in biological tissues and related materials with a spatial resolution typically ranging from 10 to 100 µm. When compared to other techniques usually employed to obtain bioimages, the greater advantage of LA-ICP-MS is its higher sensitivity. The literature survey over the last 10 years concerning the use of LA-ICP-MS for biological tissue analysis is reviewed in this article. Instrumentation, strategies of calibration for quantitative analysis, challenges and recent advances in this field are discussed. Applications of the isotope ratio (IR), including tracer experiments, and isotope dilution (ID), are reviewed for biological samples (briefly for proteins, in order to show the utility of LA-ICP-MS). Bioimaging methods, studies and applications for animal and plants tissues are emphasized, demonstrating the importance of bioimaging of metals and metalloids in biomedical research, bioaccumulation and bioavailability studies for ecological and toxicological risk assessment in humans, animals and plants. The usefulness of the IR associated with bioimaging for predicting geographical origin, habitat, movement of subjects, diet and lifestyle are also demonstrated. [ABSTRACT FROM AUTHOR]

This study evaluated the effects of HgCl2 on renal parameters in nonlactating and lactating rats and their pups, as well as the preventive role of ZnCl2. Rats received 27 mg kg−1 ZnCl2 for five consecutive days and 5 mg kg−1 HgCl2 for five subsequent days (s.c.). A decrease in δ-aminolevulinic acid dehydratase ( δ-ALA-D) activity in the blood and an increase in urine protein content in renal weight as well as in blood and urine Hg levels were observed in lactating and nonlactating rats from Sal-Hg and Zn-Hg groups. ZnCl2 prevented partially the δ-ALA-D inhibition and the proteinuria in nonlactating rats. Renal Hg levels were increased in all HgCl2 groups, and the ZnCl2 exposure potentiated this effect in lactating rats. Nonlactating rats exposed to HgCl2 exhibited an increase in plasma urea and creatinine levels, δ-ALA-D activity inhibition and histopathological alterations (necrosis, atrophic tubules and collagen deposition) in the kidneys. ZnCl2 exposure prevented the biochemical alterations. Hg-exposed pups showed lower body and renal weight and an increase in the renal Hg levels. In conclusion, mercury-induced nephrotoxicity differs considerably between lactating and nonlactating rats. Moreover, prior exposure with ZnCl2 may provide protection to individuals who get exposed to mercury occupationally or accidentally. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Triphenyltin (TPhT) is used worldwide in pesticide formulas for agriculture. Toxic effects of this compound to aquatic life have been reported; however, the biochemical response of fish exposed to different concentrations of TPhT hydroxide (TPhTH) was investigated for the first time in this study. The lethal concentration (LC 50) of TPhTH to silver catfish, Rhamdia quelen, was calculated from an acute-exposure experiment (96 h). In addition, acethylcholinesterase (AChE) activity in brain and muscle—as well as glucose, glycogen, lactate, total protein, ammonia, and free amino acids in liver and muscle—were evaluated in a chronic-exposure experiment (15-day exposure). Speciation analysis of tin (Sn) was performed in fish tissues at the end of both experiments using gas chromatography coupled to a pulsed-flame photometric detector (GC-PFPD). Concentrations of TPhT, diphenyltin, and monophenyltin (reported as Sn) were lower than limits of quantification (10σ criteria). Waterborne TPhTH concentration used through the experiment was also evaluated by GC-PFPD, and no degradation of this species was observed. The LC 50 value for silver catfish juveniles was 9.73 μg L −1 (as Sn). Decreased brain and muscle AChE activities were observed in fish exposed to TPhTH in relation to unexposed fish (control). Liver glycogen and lactate levels were significantly higher in fish kept at the highest waterborne TPhTH concentration compared with the control. Liver and muscle glucose levels of fish exposed to all TPhTH concentrations were significantly lower than those of control fish. Silver catfish exposed to all TPhTH concentrations showed lower total protein values and higher total free amino acids levels in liver and muscle compared with controls. Total ammonia levels in liver and muscle were significantly higher for the highest TPhTH concentration compared with controls. In conclusion, TPhTH caused metabolic alterations in silver catfish juveniles, and the analyzed parameters can also be used as bioindicators for TPhTH contamination. [ABSTRACT FROM AUTHOR]

A method based on microwave-induced combustion (MIC) was applied for digestion of active pharmaceutical ingredients (APIs) and subsequent determination of bromine and iodine by inductively coupled plasma mass spectrometry (ICP-MS). Ten APIs including amoxicillin, atenolol, clavulanic acid, clonazepan, diltiazem, haloperidol, imipramine, nimesulide, propranolol and sodium diclofenac were decomposed by MIC. Combustion of 500 mg of each API was possible in less than 30 s using 20 bars of oxygen as initial pressure. A single and diluted solution (50 mmol L−1 (NH4)2CO3) was used for the absorption of both analytes and a reflux step of 5 min was applied to improve analyte recoveries. Final digests were suitable to Br and I determination by ICP-MS. Accuracy was evaluated using certified reference materials and agreement better than 95 and 97% for Br and I was obtained, respectively. Results were also compared with those obtained by ion chromatography (IC). The carbon content in digests obtained after decomposition was lower than 500 mg L−1 avoiding interferences in the determination step for both techniques. With the use of MIC, up to eight samples could be processed simultaneously and only diluted solutions are required, minimizing reagent consumption and waste generation. The limits of detection for Br and I by ICP-MS were 0.02 and 0.001 μg g−1, respectively, that were considered suitable for the determination of these elements in the investigated active pharmaceutical ingredients. [ABSTRACT FROM AUTHOR]

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Iodine determination in food samples was performed by inductively coupled plasma mass spectrometry (ICP-MS) after digestion by microwave-induced combustion (MIC). Sample masses up to 500 mg of bovine liver, corn starch, milk powder, or wheat flour were completely combusted using the MIC system. Ammonium nitrate (6 mol l solution, 50 μl) was used as an aid for ignition and vessels were charged with 15 bar of O. The use of HO, 0.9 mmol l HO, 10 to 50 mmol l (NH)CO and 56 mmol l tetramethylammonium hydroxide was investigated as absorbing solutions, as well as the suitability of performing a reflux step after the combustion process. Digestion of food samples by pressurized microwave-assisted acid digestion, microwave-assisted extraction and conventional extraction of iodine in alkaline solution were also evaluated. Iodine recoveries higher than 99% were obtained using MIC and 50 mmol l (NH)CO or 56 mmol l tetramethylammonium hydroxide as absorbing solution and with 5 min for the reflux step. Accuracy was evaluated using certified reference materials (bovine muscle, corn bran, and milk powder) and agreement better than 97% was obtained. The limit of quantification by MIC and further ICP-MS determination was 0.002 µg g. Blanks were always low and no memory effects were observed. Digestion by MIC allowed the processing of up to eight samples by each run in 25 min with high efficiency of digestion (residual carbon content lower than 1%) providing a suitable medium for further iodine determination by ICP-MS. [ABSTRACT FROM AUTHOR]

A procedure for trace determination of Cd and Pb in medicinal samples using solid sampling flame atomic absorption spectrometry (SS-F AAS) was developed for trace determination of Cd and Pb in medicinal plants. Powdered samples were mixed with high purity graphite and introduced as pellets (up to 100 mg) into a quartz device positioned above the burner and heated by air-acetylene flame. Oxygen flowing through the quartz device assure the complete combustion of sample. Combustion was started in 2 s after sample introduction and the produced vapours were subsequently dispersed into the flame. Calibration was performed using different masses of solid certified reference material (for Pb) or with reference solutions applied directly on graphite pellets (for Cd). Integrated absorbance mode was used and signals were integrated in less than 10 s. A deuterium background corrector was used throughout. Characteristic masses were 58 and 790 pg for Cd and Pb, respectively. Accuracy was checked using certified reference materials and the percent relative error was between -7 and 2% for Cd and between -2 and 3% for Pb. Relative standard deviations (repeatability) were always below 10% (n = 5). Limits of detection were 0.012 and 0.10 µg g-1 for Cd and Pb, respectively. The proposed procedure by SS-F AAS is simple and may be applied to conventional atomic spectrometers allowing the determination of Cd or Pb in 40 test samples by hour (excluding the steps for sample preparation). [ABSTRACT FROM AUTHOR]

Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) has become established as a very efficient and sensitive trace, ultratrace, and surface analytical technique in the life sciences. We have developed a new analytical imaging technique using LA-ICP-MS to study element distribution in biological tissues. Nowadays, imaging LA-ICP-MS using double-focusing sector field (LA-ICP-SFMS) or quadrupole-based mass spectrometers (LA-ICP-QMS) can be applied as an exciting tool providing new information on the pathophysiology, pharmacology, and toxicology of elements of interest in biological systems. The quantitative determination of elements (e.g., Cu, Fe, Zn, Se, and others) in biological tissues is of growing interest especially in brain research (e.g., for studying neurodegenerative diseases such as Alzheimer's or Parkinson's disease). LA-ICP-SFMS was employed to produce images of detailed regionally specific element distributions in thin tissue sections of different sizes (such as control human or rat brain tissues or tumor regions). In addition, imaging MS using LA-ICP-QMS was applied to study the uptake and transport of nutrient and toxic elements in plant tissues. Besides the quantitative imaging of essential and toxic elements in tissues, powerful analytical techniques are also required for the determination and characterization of phosphoproteins and metal-containing proteins within a large pool of proteins, after electrophoretic separation [e.g., blue native polyacrylamide gel electrophoresis (BN-PAGE) and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE)] into 1D and 2D gels. LA-ICP-MS was used to detect metalloproteins in protein bands of 1D gels or protein spots separated after 2D gel electrophoresis (2D-GE). In addition to elemental determination by LA-ICP-MS, matrix-assisted laser desorption/ionization, or MALDI-MS, was employed to identify metal-containing proteins. Recent progress will be discussed in applying LA-ICP-MS in the life sciences, including the imaging of thin slices of tissue and applications in proteome analysis in combination with MALDI-MS to investigate phosphoproteins and metal-containing proteins. [ABSTRACT FROM AUTHOR]