SRM 1573a Research Articles

New Insights into Trace Element Accumulation in Kernels of Two Algerian Populations of Argan (Argania spinosa (L.) Skeels): An Endangered Endemic Tree.

Argan is one of the valuable oilseed trees in the Northwest Africa area, with important ecological and socioeconomic benefits; however, information underlying its elemental status remains absent . The current work was performed for the first time to quantify the mineral status of Argania spinosa kernels collected from two different geographic Algerian regions (Mostaganem and Tindouf). Elemental investigation (As, Br, Ca, Ce, Co, Cr, Fe, K, La, Na, Rb, Sb, Sc, Sm, Th, and Zn) was performed using neutron activation analysis (NAA). Two standard reference materials from the National Research Center for certified reference materials (China), namely, CRM-GBW 07605 (GSV-4 tea leaves), and the National Institute of Standards and Technology (USA), namely, NIST (SRM 1573a, tomato leaves), were used to ensure precision and validation of NAA measurements. A computational calculation of data including principal component analysis (PCA) and Pearson correlation coefficient (r) was applied. The extents of essential elements in Mostaganem kernels were found to be in the order of K (7185 μg g-1) > Ca (2079 μg g-1) > Na (205 μg g-1) > Fe (84.33 μg g-1) > Zn (73.41 μg g-1) > Cr (0.66 μg g-1) > Co (0.035 μg g-1), whereas the overall order of these elements in Tindouf kernels was K (7206 μg g-1) > Ca (3725 μg g-1) > Fe (114.69 μg g-1) > Zn (67.37 μg g-1) > Na (56.29 μg g-1) > Cr (0.54 μg g-1) > Co (0.11 μg g-1). PCA results revealed that Tindouf population was highly loaded with Br, Cr, Cu, Mn, Sr, V, and Zn, while Mostaganem population was associated only with Ce and Sm contents. These findings can be useful for making new formulations for cosmetic and culinary usage and contribute to the nutritional database and food safety.

Determination of technology-critical elements in seafood reference materials by inductively coupled plasma-tandem mass spectrometry

The certified reference materials (CRMs) BCR-668 (mussel tissue), NCS ZC73034 (prawn), NIST SRM 1566a (oyster tissue) and NIST SRM 2976 (mussel tissue) were analyzed for their mass fractions of 23 elements using inductively coupled plasma tandem-mass spectrometry (ICP-MS/MS). This study focused on the quantification of selected technology-critical elements (TCEs), specifically rare earth elements (REE) and the less studied TCEs Ga, Ge, Nb, In and Ta. Microwave assisted closed vessel digestion using an acid mixture of HNO3, HCl and H2O2 was applied to varying sample masses and two different microwave systems. Recoveries of 76% (Gd, NCS ZC73034) to 129% (Lu, BCR-668) were obtained for the REE and 83% (Ge, NCS ZC73034) to 127% (Nb, NCS ZC73034) for the less studied TCEs across all analyzed CRMs (compared to certified values) using the best-performing parameters. Mass fractions for all analyzed, non-certified elements are suggested and given with a combined uncertainty U (k = 2), including mass fractions for Ga (11 µg kg-1 ± 9 µg kg-1 to 67 µg kg-1 ± 8 µg kg-1) and In (0.4 µg kg-1 ± 0.3 µg kg-1 to 0.8 µg kg-1 ± 0.7 µg kg-1). This study provides mass fractions of possible new emerging contaminants and addresses the relevant challenges in quantification of less studied TCEs, thus allowing the application of existing CRMs for method validation in studies dealing with the determination of TCEs in seafood or other biota.Graphical abstract

Maternal urban particulate matter (SRM 1648a) exposure disrupted the cellular immune homeostasis during early life: The potential attribution of altered placental transcriptome profile

Ambient fine particular matter (PM2.5) exposure has been associated with numerous adverse effects including triggering functional disorders of the placenta and inducing immune imbalance in offspring. However, how maternal PM2.5 exposure impacts immune development during early life is not fully understood. In the current study, we exposed mice with low-, middle-, and high-dose PM2.5 during pregnancy to investigate the potential link between the transcriptional changes in the placenta and immune imbalance in mice offspring induced by PM2.5 exposures. Using flow cytometry, we found that the proportions of B cells, CD3+CD4+ T cells, CD3+CD8+ T cells, and macrophage (Mφ) cells were altered in the blood of PM2.5-exposed mice pups but not dendritic cells (DCs) and natural killer cells (NKs). Using bulk RNA sequencing, we found that PM2.5 exposure altered the transcriptional profile which indicated an inhibition of the complement and coagulation cascades in the placenta. Weighted gene co-expression network analysis (WGCNA) revealed the potential crosstalk between the perturbation of placental gene expression and the changes of immune cell subsets in pups on postnatal day 10 (PND10). Specifically, WGCNA identified a cluster of genes including Defb15, Defb20, Defb25, Cst8, Cst12, and Adam7 that might regulate the core immune cell types in PND10 pups. Although the underlying mechanisms of how maternal PM2.5 exposure induces peripheral lymphocyte disturbance in offspring still remain much unknown, our findings here shed light on the potential role of placental dysfunction in these adverse effects.

Development of a Method for the Determination of Total Selenium in Soil, Maize Plants, and Maize Flour by Inductively Coupled Plasma Tandem Mass Spectrometry (ICP-MS/MS)

Selenium (Se) is a micronutrient that has multiple biochemical effects ranging from a nutritional deficiency at low levels to toxicity at high levels. Its quantification in environmental systems is vital to protect the health of people and animals. This study developed and validated methods to determine the total selenium (Se) concentration in soil, maize plants, and maize flour. The performance of the methods was ascertained using matrix certified reference materials (CRMs), namely NMIJ CRM 7303-a (trace elements in lake sediments), NIST SRM 1646-a (estuarine sediments), NIST SRM 1570-a (spinach leaves), NIST SRM 1571 (orchard leaves), NCS ZC 73010 (maize flour) and NIST RM 8437 (hard red spring wheat flour). All methods fulfilled the performance requirements of the AOAC International. An acceptable accuracy was achieved with percentage recoveries between 57 and 102% and E n ‐ scores within ±1 limits. Repeatability ( RSD r , % ) and intermediate precision ( RSD R , % ) ranged from 4 to 12%, and 9 to 15%, respectively. The limit of detection (LOD) and limit of quantification (LOQ) for soil were 0.024 ng. g−1 and 0.082 ng. g−1, respectively. The LODs and LOQs for maize plants and flour were 0.0036 and 0.0179 ng. g−1, respectively. The performance characteristics of the methods were comparable with previously reported methods, confirming reliability. The measurement uncertainty was evaluated following the guide to the expression of uncertainty in measurement (GUM). Relative expanded uncertainty at a 95% level of confidence ( k = 2 ) was less than 24% for the final measurement results for all the different matrices.

Air pollution induces pyroptosis of human monocytes through activation of inflammasomes and Caspase-3-dependent pathways

According to the World Health Organization (WHO), air pollution is one of the most serious threats for our planet. Despite a growing public awareness of the harmful effects of air pollution on human health, the specific influence of particulate matter (PM) on human immune cells remains poorly understood. In this study, we investigated the effect of PM on peripheral blood monocytes in vitro. Monocytes from healthy donors (HD) were exposed to two types of PM: NIST (SRM 1648a, standard urban particulate matter from the US National Institute for Standards and Technology) and LAP (SRM 1648a with the organic fraction removed). The exposure to PM-induced mitochondrial ROS production followed by the decrease of mitochondrial membrane potential and activation of apoptotic protease activating factor 1 (Apaf-1), Caspase-9, and Caspase-3, leading to the cleavage of Gasdermin E (GSDME), and initiation of pyroptosis. Further analysis showed a simultaneous PM-dependent activation of inflammasomes, including NLRP3 (nucleotide-binding oligomerization domain-like receptor pyrin domain containing 3) and Caspase-1, followed by cleavage of Gasdermin D (GSDMD) and secretion of IL-1β. These observations suggest that PM-treated monocytes die by pyroptosis activated by two parallel signaling pathways, related to the inorganic and organic PM components. The release of IL-1β and expression of danger-associated molecular patterns (DAMPs) by pyroptotic cells further activated the remnant viable monocytes to produce inflammatory cytokines (TNF-α, IL-6, IL-8) and protected them from death induced by the second challenge with PM.In summary, our report shows that PM exposure significantly impacts monocyte function and induces their death by pyroptosis. Our observations indicate that the composition of PM plays a crucial role in this process—the inorganic fraction of PM is responsible for the induction of the Caspase-3-dependent pyroptotic pathway. At the same time, the canonical inflammasome path is activated by the organic components of PM, including LPS (Lipopolysaccharide/endotoxin).Graphical PM-induced pyroptosis of human monocytes. Particulate matter (PM) treatment affects monocytes viability already after 15 min of their exposure to NIST or LAP in vitro. The remnant viable monocytes in response to danger-associated molecular patterns (DAMPs) release pro-inflammatory cytokines and activate Th1 and Th17 cells. The mechanism of PM-induced cell death includes the increase of reactive oxygen species (ROS) production followed by collapse of mitochondrial membrane potential (ΔΨm), activation of Apaf-1, Caspase-9 and Caspase-3, leading to activation of Caspase-3-dependent pyroptotic pathway, where Caspase-3 cleaves Gasdermin E (GSDME) to produce a N-terminal fragment responsible for the switch from apoptosis to pyroptosis. At the same time, PM activates the canonical inflammasome pathway, where activated Caspase-1 cleaves the cytosolic Gasdermin D (GSDMD) to produce N-terminal domain allowing IL-1β secretion. As a result, PM-treated monocytes die by pyroptosis activated by two parallel pathways—Caspase-3-dependent pathway related to the inorganic fraction of PM and the canonical inflammasome pathway dependent on the organic components of PM.

Bioaccessibility of Fifteen Elements from Dried Fruits by the BARGE (Bioaccessibility Research Group of Europe) Unified Bioaccessibility Method (UBM) and Multivariate Statistical Analysis

The BARGE (Bioaccessibility Research Group of Europe) unified bioaccessibility method (UBM) was applied to assess the bioaccessibility of essential and toxic elements (B, Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Rb, Sr, Mo, and Cd) in 11 dried fruit samples, two certified reference materials, and British Geological Survey guidance material (BGS) 102. The total, UBM gastric, and gastro-intestinal (GI) phase concentrations of elements were determined by inductively coupled plasma—mass spectrometry. The accuracy of the methods was verified using BGS 102 for the BARGE UBM and SRM 1573a for total concentrations. The order for mean bioaccessible fractions (BF %) in gastric phase for the dried fruit was Rb (101) > Sr (79) > Mn (59) > Cr (46) > Ni (37) > Fe (36) = Zn (36) > Cu (33) > Co (32) > Al (24) > V (22) > B (19) > Cd (18) > Mo (8) > As (6). Total and bioaccessible concentrations for Mn, Rb, and Sr are significantly and positively correlated with each other. Multivariate statistical analysis was used to classify bioaccessible elements and samples in gastric and GI phases.

Selenium quantification in wastewaters from selected coal-fired power plants and river waters in South Africa using ICP-MS

South Africa mainly relies on Eskom's coal-fired power plants for electricity generation. However, the use of coal causes several adverse environmental impacts, including the release of selenium into the hydrosphere. Selenium is an essential nutrient for humans, animals, and microbes, but excess selenium is toxic. This paper describes the determination of total dissolved selenium in wastewater from selected coal-fired power plants and river waters near coal-fired power plants in South Africa. A sensitive and robust inductively coupled plasma mass spectrometry (ICP-MS) method for determining total dissolved selenium in wastewater and river water was developed using a certified reference material (NIST SRM 1640a Trace Elements in Natural Water). The results agreed with the certified values, with percentage recoveries ranging from 92–96%. The method detection limit was 0.13 µg/L. Total Se concentrations in wastewater samples from Kriel and Lethabo Power Stations ranged between 4.86 and 8.53 µg/L, and in river water samples from the Olifants and Wilge Rivers, the concentrations ranged from 2.63–8.20 µg/L. These results indicate that the Se levels in the wastewater are too low to pose a health hazard to humans and livestock but pose an environmental threat to aquatic life. The low concentrations in the river samples also show that there may be slight Se pollution (regarding aquatic life) from the selected coal-fired power plants in South Africa. There may be slight Se pollution (with regards to aquatic life) from Duvha and Kendal Power Stations because an increase from 2–8 µg/L was observed in river water samples collected near these selected coal-fired power plants.

Selective and fast magnetic dispersive solid phase micro-extraction of copper and lead in water and vegetables after synthesis of magnetic mesoporous carbon

Magnetic mesoporous carbon (Fe3O4@C, MMC) was synthesized and characterized. It was used for the first time as a sorbent for the magnetic dispersive solid phase microextraction (M-dSPμE) of copper and lead in water and vegetables. FAAS was used to determine the analyte concentrations after elution. The MMC was found to be have surface area of 145.9 m2 g−1 and average pore diameter of 15 nm. The analytical parameters affecting M-dSPμE of copper and lead were optimized. They were pH of sample, 6; eluent, 2 mol L−1 HCl (3 mL); and sample volume, 250 mL. The MMC reaches equilibrium very fast without vortexing for adsorption and only 5 s for elution. The LOD and PF of the M-dSPμE method for copper and lead were found to be 0.87 μg L−1 and 83 for Cu(II) and 2.8 μg L−1 and 167 for Pb(II), respectively. The precision of the M-dSPμE method was found to be ≤ 3.2%. The M-dSPμE method was verified by certificate reference materials (TMDA-53.3 Fortified Lake water and NIST SRM 1573a Tomato Leaves). It was successfully applied to the determination of copper and lead in lake water, wastewaters, sea water, radish, spinach, lettuce, and celery samples.

Development of a New Sensitive Method for Lead Determination by Platinum-Coated Tungsten-Coil Hydride Generation Atomic Absorption Spectrometry.

A novel very sensitive and rapid analytical method was improved where gaseous lead formed was transported to and trapped on an externally heated platinum-coated tungsten-coil atom trap for in situ preconcentration. The analytical performance of the developed method with the graphite furnace atomic absorption spectrometry (GFAAS) method was compared. All critical parameters affecting the performance of both methods were optimized. The limit of quantitation (LOQ) was found as 11.0 ng L-1 and the precision was 2.3% in terms of percent relative standard deviation (RSD%). Characteristic concentration (Co) of the developed trap method was indicating a 32.5-fold enhancement in sensitivity compared to the GFAAS method. In order to investigate the surface morphology of the W-coil, scanning electron microscope-energy-dispersive X-ray (SEM-EDS) analyzes were performed. The accuracy of the trap method was tested by certified reference materials: NIST SRM 1640a (the elements in natural water) and DOLT:5 (dogfish liver). Interferences from other hydride-forming elements were investigated. Application of the trap method was demonstrated by the analysis of some drinking water and fish tissue samples. The t test was applied to drinking water samples, and the results indicated that there was no statistically significant error.

Investigation of the Immunogenic Properties of Ovalbumin Modified by Urban Airborne Particulate Matter

Exposure to air particulate matter (PM) is linked to the blood oxidative stress and systemic inflammation. The aim of this study was to elucidate whether oxidative PM modification of ovalbumin (OVA), the major antioxidant serum protein, may alter its antigenicity and/or immunogenicity. Ovalbumin was exposed via dialysis to the standard urban PM (SRM 1648a) or to PM with removed organic content (encoded as LAP). Both structural changes and biological properties of PM-modified OVA were measured. T lymphocytes and dendritic cells (the major antigen-presenting cells) isolated from C57BL/6 and OT-II (323–339 epitope) OVA-specific T cell receptor (TCR)-transgenic mice were used to test the effect of PM on OVA immunogenicity. The immunogenicity of both SRM 1648a and LAP-modified OVA was significantly higher than that of control OVA, as measured by the epitope-specific T cell proliferation and interferon γ production by the stimulated cells. This effect was associated with mild oxidative changes in the carrier molecule outside the structure of the OVA epitope and with increased resistance to proteolysis of PM-modified OVA. Interestingly, dendritic cells showed enhanced capacity for the uptake of proteins when the cells were cultured with PM-modified OVA. Our results suggest that the enhanced immunogenicity of PM-modified OVA is not associated with altered antigenicity or antigen presentation. However, it may result from slower degradation and longer persistence of modified antigens in dendritic cells. Whether this phenomenon is associated with enhanced risk prevalence of autoimmune diseases observed in the areas with high urban PM pollution needs to be explained.

Simultaneous Hydride Generation Inductively Coupled Plasma Mass Spectrometry for the Evaluation of Different Generations of Soybean Seeds

A methodology for simultaneous hydride forming elements was established with accuracy and precision, and alicable to different generations of the soybean seeds. In fact, a unique condition for As, Se, Sb and Te determination by hydride-generation coupled to ICP-MS was established as the optimized concentrations of HCl at 6 mol/L and sodium tetrahydroborate at 0.3% (m v-1), and the analytical curve prepared containing all four elements ranging from 10 to 100 ng L-1. For checking the accuracy, the NIST SRM 1568a (Rice Flour) material was used, and good recoveries ranging from 71.7 to 126% were found for the hydrides forming elements. After optimizing, the method was alied to different generations of soybean seeds, indicating a low content of As (from 17 to 29 ng kg-1) and Se (from 42 to 50 ng kg-1) in some of these generations, and concentrations below the LOQ for Sb and Te. All evaluations were obtained after analyzing, at least, in triplicates. Although found low concentrations for As and Se, these results are, at least, intriguing, because they not follow a tendency along generations, and they are discussed along the text.

Development of a Sensitive Method for Cadmium Determination in Fish Tissue and Drinking Water Samples by FAAS Using SQT In Situ Atom Trapping.

A sensitive and robust trap method was developed for the determination of cadmium (Cd) by using a slotted quartz tube. Using this method at a sample suction rate of 7.4 mL/min for 4.0 min collection, a 1467-fold increase in sensitivity was obtained compared to the flame atomic absorption spectrometry method. Under the optimized conditions, a limit of detection of 0.075 ng mL-1 was obtained for the trap method. The interference effects of hydride-forming elements, transition metals, and some anions on the Cd signal were investigated. The developed method was evaluated by analyzing "Sewage Sludge-industrial origin (BCR no: 146R)", "NIST SRM 1640a Trace elements in natural water", and "DOLT: 5 Dogfish Liver". There was a good agreement between the certified and found values at the 95% confidence level. This method was applied successfully for the determination of Cd in drinking water and some fish tissue samples (liver, muscle, and gill) obtained from Muğla province.

Determination and speciation of methyl mercury and total mercury in fish tissue samples by gold-coated W-coil atom trap cold vapor atomic absorption spectrometry

A sensitive analytical technique was developed where gaseous mercury formed by sodium tetrahydroborate reduction is transported to and trapped on a resistively heated gold-coated Tungsten-coil atom trap for in situ preconcentration. This technique was applied successfully for determination and speciation of methyl mercury and total mercury in some fish tissue samples (liver, muscle and gill) obtained from Muğla province. The analytical parameters were optimized both for trap and no-trap studies. Under the optimized conditions, a limit of detection (LOD) of 6.0 ng/L was obtained. The precision was evaluated by relative standard deviation (RSD%) corresponding to 4.1% (n = 11). Accuracy of the proposed method was evaluated by analyzing “DOLT:5 Dogfish Liver”, “NIST SRM 1640a Trace elements in natural water” and “NIST 1946 Lake Superior fish tissues”. The measurements of the certified reference materials were in good agreement with the certified values at the 95% confidence level.

Effects of maternal urban particulate matter SRM 1648a exposure on birth outcomes and offspring growth in mice.

The association between exposure to particulate matter (PM) during pregnancy and abnormal birth outcomes is still inconclusive. This study aims to provide more evidence for this public health concern by investigating birth outcomes and the growth of offspring in mice exposed to PM during pregnancy. C57BL/6J pregnant mice were exposed to PM via nasal drip at three doses or solvent control. The dam weight gain was recorded during pregnancy. The number of pups, pup weight, and placental weight were recorded at embryonic day 18.5 (E18.5) necropsy. For mice that gave birth naturally, we calculated the gestation length and measured the body weight of offspring once a week from the 1st to the 6th week after birth. The results showed that there were no significant differences in maternal body weight gain, conception rate, pregnancy duration, and litter size among different groups. There were no significant differences in fetal weight, placental weight, and fetal/placental weight ratio at E18.5. Weight gain in offspring was reduced after birth. The average body weight of offspring in the high-dose group was significantly lower than that in the control group at weeks 5 in female pups. There were no significant differences in the body weight of male offspring among groups from 1st to the 6th. Together, our study indicated that maternal exposure to PM did not significantly impact birth outcomes of C57BL/6J mice but affected growth trajectories in offspring after birth in a dose- and fetal sex-dependent manner.

The Effect of Inhaled Air Particulate Matter SRM 1648a on the Development of Mild Collagen-Induced Arthritis in DBA/J Mice

Air pollution is considered to be one of a risk factor for rheumatoid arthritis (RA). Collagen-induced arthritis (CIA) is commonly used as a mouse model of human RA. However, the impact of specific particulate matter (PM) components on the incidence and severity of RA has still not been established. The aim of this study was to develop an experimental model of CIA suitable to test arthritogenicity of inhaled PM. A mild form of CIA was induced in DBA1/J mice inhaled with various components of SRM 1648a PM. The incidence and severity of arthritis was assessed, and the selected serum markers of autoimmunity and inflammation were determined. Clinical arthritis was observed from the booster CII immunisation onward. Anti-cyclic citrullinated peptide antibodies, a diagnostic marker of RA, were detected in serum of these mice. All inhaled pollutants, crude PM, PM with reduced organic content, ferric, and silica nanoparticles markedly increased CIA incidence and severity. The fastest progression of CIA development was caused by crude PM and was linked to enhanced serum levels of anti-CII IgG, the prominent arthritogenic autoantibodies. On the other hand, inhaled nanoparticles enhanced serum levels of TNFα, a major proinflammatory arthritogenic cytokine. We recommend this experimental model of mild CIA to test the mechanisms of arthritis exacerbation by inhaled air pollutants. Further studies are necessary to determine whether PM-aggravated arthritis is caused by inflammatory mediators translocated from inflamed lung into systemic circulation or whether PM translocated into the bloodstream directly exacerbate joint inflammation.

Deep eutectic solvent-based three-liquid-phase-extraction system for one-step separation of Cu, Mg and Zn in water samples

A novel and environmentally friendly three-liquid-phase extraction (TLPE) approach was developed for simultaneous separation of copper (Cu), magnesium (Mg) and zinc (Zn) from water samples. The proposed organic/two aqueous phase system consists of di(2-ethylhexyl)phosphoric acid (D2EHPA), Choline Chloride:urea (deep eutectic solvent (DES)), and salt (K2HPO4). The effects of various factors including amount of DES and K2HPO4, pH, D2EHPA concentration, phase-mixing time, and diluent on the preconcentration/separation of Cu, Mg and Zn were evaluated. The results showed that 96.6% of Zn was concentrated in the D2EHPA-rich top phase, whereas 97.8% of Cu and 98.1% of Mg were quantitatively extracted into the DES-rich middle phase and salt-rich bottom phase, respectively. Excellent recovery (>97%) of Cu, Mg and Zn was obtained by using 20% (v/v) D2EHPA in hexane, and 1.72 g DES and 3.12 g K2HPO4 in two lower aqueous phases at pH= 4. The limits of detection were 1.58, 1.55 and 2.37 mg/L for Cu, Mg and Zn, respectively. Relative standard deviations (RSDs) for 0.5 mg/L and 1.0 mg/L of Cu, Mg and Zn in water samples were < 6%. The accuracy of the procedure was confirmed by analyzing a certified reference material of water and tea (NIST SRM 1640a, GBW 07605). Under optimized conditions, excellent agreement was observed between the TLPE-flame atomic absorption spectrometry (FAAS) results and certified values using the student’s t-test (P = 0.05). TLPE procedure was successfully applied for the determination of Cu, Mg and Zn in water samples.

Psittaciformes mineral feed analysis method choice and optimization employing chemometric tools

BackgroundIn this work, a multivariated approach based on factorial design and principal component analysis was used to perform the optimization of sample decomposition. The method was applied for the first time to quantify several chemical elements (Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, P, Pb, Se and Zn) in Psittaciformes feed. The choice of the best sample decomposition method is a challenging task considering all variables involved in the process. Generally, this choice is made by using individual monovariated experiments and sometimes interaction effects between these variables as mass of the sample, acid composition, temperature, etc, are not considered. MethodsSample decomposition: 200 mg of sample was mixed with 3.5 mL of HNO3 65% and left at room temperature for 24 h, in a pre-decomposition step, heated at 150 °C for 50 minutes employing a digestion block and mixed with 1.5 mL of H2O2 in the last ten minutes of decomposition. Chemical analysis: A total of 44 samples of Psittaciformes feed digests, among extruded feed, flour and snacks), purchased at pet stores or similar stores in six states in Brazil, were analyzed by inductively coupled plasma optical emission spectrometry (ICP OES). Method accuracy was assessed using certified reference materials SRM 1567a, SRM 1573a, SRM 1577b and IMEP 19. ResultsThe limits of detection (LoD) and quantification (LoQ) ranged from 0.02 mg kg−1 to 0.07 mg kg−1 (Se) and from 1.79 mg kg−1 to 5.41 mg.kg−1 (Ca), respectively. The concentration of chemical elements in animal food ranged from <0.27 mgkg −1 (Fe) to 41.4 ± 2.9 g kg−1 (P), in flour concentrations ranged from <0.05 mg kg−1 (Mg) to 23.8 ± 4.1 g kg−1 (P) and concentrations ranged from <0.05 mg kg−1 (Mn) to 6.8 ± 0.9 g kg−1 (Ca) in snacks. ConclusionThe approach based on multivariate analysis to perform a sample decomposition was successfully applied for Psittaciformes feed. In general, the chemical elements listed on the product labels (Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, P, Pb, Se and Zn) were detected at variable contents when compared to the recommender nutritional values. Toxic elements, Cd and Pb were not detected in any of the analyzed samples. The detection and quantification of chemical elements not listed in nutritional tables and in each product label indicates that mineral addition by manufacturers is performed without considering the chemical composition of the raw materials used in the production process, which can lead to nutritional issues. Thus, a broad revision of Brazilian Legislation concerning product classification considering quality and mineral addition criteria in daily animal feed, especially pets, is urgently required.

Use of slow atomization ramp in high resolution continuum source graphite furnace atomic absorption spectrometry for the simultaneous determination of Cd and Ni in slurry powdered chocolate samples

A methodology for simultaneous (not sequential) determination of Cd and Ni in powder chocolate samples by high-resolution continuum source graphite furnace atomic absorption spectroscopy (HR–CS–GF-AAS) and slurry sample analysis was developed. Acid digestion of the samples was not necessary, considering the high total fat content of this type of matrix (above 10 %), and no apparent deterioration of the graphite tubes was even observed once these samples were subjected to analysis. Despite the volatilities of both elements are quite different, simultaneous quantification was achieved using a slow heating ramp atomization, covering a convenient and wide temperature gradient for Cd volatilization at low temperatures and subsequent atomization of Ni at elevated temperatures, using the same heating program without an apparent change in sensitivity. This slow heating ramp was essayed between 200 and 1500 °C·s−1 and optimized at 400 °C·s−1, achieving the simultaneous measuring of Cd in the principal line (228.8018 nm) and using a secondary for Ni (228.9984 nm). No stop events for sequential changes in wavelength or temperature additional steps were involved in the method and molecular spectral interferences overlapping the analyte signals were corrected appropriately by a pragmatic strategy taking advantage of the fine structure signals adjacent to analyte signals within the same spectrum recorded. Palladium matrix modifier and aqueous standards were used for the calibration and determination of both elements in the samples. The method accuracy was successfully confirmed using a reference material (NIST SRM 1573a). An improvement in the sensitivity of Ni was found using a greater number of pixels for signal integration, central and five adjacent pixels (CP ± 5), while a lengthening of the linear range of Cd was obtained by using an attenuated signal (±2) or using only one pixel (CP). The limits of detection were 0.027 μg g−1 and 0.22 μg g−1 for Cd and Ni respectively by this simple methodology using aqueous standards for calibration and the simultaneous determination of both elements in the same measurement. The respective limits of quantification for Cd and Ni were 0.090 and 0.72 μg g−1 and the relative standard deviations in samples (n = 5) were about 4–20% and 0.3–11% for Cd and Ni respectively. The optimized method was used for the determination of both elements in real samples purchased from retail supermarkets finding variable concentrations between 0.5 and 5.7 μg g−1 for Cd and 2.1–10.9 μg g−1 for Ni, comparable to levels reported in the literature referred to elsewhere in the world.

Multielement determination of metals in edible seeds by HR-CS GF AAS and direct analysis

This work reports, for the first time, the multielement determination of Cd, Ni and Fe concentrations in edible seeds via high-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS GF AAS), using direct solid sample analysis. First, Cd (228.802 nm) concentration was determined using 400 and 1600 °C as pyrolysis and atomisation temperatures, respectively. In sequence, from the same sample aliquot, Ni (232.003 nm) and Fe (232.036 nm) concentrations were determined using 2500 °C as the atomisation temperature. A combination of Pd/Mg and H2O2 was used as a chemical modifier to improve the precision and overcome smoke interferences. Multielement aqueous standard solutions were used for calibration, and the detection limits were 3.1 µg kg−1 for Cd, 0.062 mg kg−1 for Ni and 3.4 mg kg−1 for Fe. The trueness was proven by analysing a standard reference material of Tomato Leaves (NIST SRM 1573a). The following concentration ranges were found in the samples: 39–254 µg kg−1 for Cd; 1.1–8.0 mg kg−1 for Ni; and 38–147 mg kg−1 for Fe. The Cd contents in with-shell pumpkin and in roasted and raw sunflower seed samples were above the maximum acceptable Cd level in cereals, as established by the Codex Alimentarius Commission of 100 µg kg−1.

Bioaccessibility of Cu, Mn, Fe, and Zn in Fruit and Vegetables by the In Vitro UBM and Statistical Evaluation of the Results.

The total, gastric, and gastro-intestinal Cu, Mn, Fe, and Zn concentrations in eight fruit and vegetable samples were investigated. The unified bioaccessibility method (UBM) developed by BARGE (Bioaccessibility Research Group of Europe) was performed for in vitro bioaccessibility experiments. Total and bioaccessible concentrations of Cu, Mn, Fe, and Zn were determined by ICP-OES and ICP-MS, respectively. The accuracy of the methods was verified using BGS 102 for the BARGE UBM and SRM 1573a for total analysis. The mean BF (%) order for Cu, Mn, Fe, and Zn was Mn (101) > Zn (88) > Fe (60) > Cu (30) in gastric phase and Mn (78) > Zn (69) > Fe (46) > Cu (29) in gastro-intestinal phase. The results show that Mn and Zn in all the samples have the greatest bioaccessible values, while the values for Cu are much lower. The relationships among total, gastric, and gastro-intestinal element concentrations were investigated using statistical analysis such as correlation analysis, principal component analysis (PCA), and cluster analysis (CA). Total and bioaccessible Cu, Mn, and Zn concentrations were significantly correlated with each other.