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Mercury (Hg) is a toxic element which impacts on biological systems and ecosystems. Because the toxicity of Hg species is highly dependent on their concentration levels and chemical forms, the sensitive identification of the chemical forms of Hg-i.e., Hg speciation-is of major significance in providing meaningful information about the sources of Hg exposure. In this study, a microfluidic-based device made of high-clarity poly(methyl methacrylate) (PMMA) was fabricated. Then, titanium dioxide nanoparticles (nano-TiO2s) were attached to the treated channel's interior with the aid of poly(diallyldimethylammonium chloride) (PDADMAC). After coupling the nano-TiO2-coated microfluidic-based photocatalyst-assisted reduction device (the nano-TiO2-coated microfluidic-based PCARD) with high-performance liquid chromatography (HPLC) and inductively coupled plasma mass spectrometry (ICP-MS), a selective and sensitive, hyphenated system for Hg speciation was established. Validation procedures demonstrated that the method could be satisfactorily applied to the determination of mercury ions (Hg2+) and methylmercury ions (CH3Hg+) in both human urine and water samples. Remarkably, the zeta potential measured clearly indicated that the PDADMAC-capped nano-TiO2s with a predominance of positive charges indeed provided a steady force for firm attachment to the negatively charged device channel. The cause of the durability of the nano-TiO2-coated microfluidic-based PCARD was clarified thus.
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Marginalized communities experience barriers that can prevent soil monitoring efforts and knowledge transfer. To address this challenge, this study compared two analytical methods: portable X-ray fluorescence spectroscopy (pXRF, less time, cost) and inductively coupled plasma mass spectrometry (ICP-MS, "gold standard"). Surface soil samples were collected from residential sites in Arizona, USA (N = 124) and public areas in Troy, New York, USA (N = 33). Soil preparation differed between groups to account for community practice. Statistical calculations were conducted, paired t test, Bland-Altman plot, and a two-way ANOVA indicated no significant difference for As, Ba, Ca, Cu, Mn, Pb, and Zn concentrations except for Ba in the t test. Iron, Ni, Cr, and K were statistically different for Arizona soils and V, Ni, Fe, and Al concentrations were statistically different for New York soils. Zinc was the only element with high R2 and low p value. Pollution load index (PLI), enrichment factors (EF), and geo-accumulation index (Igeo) were calculated for both methods using U.S. Geological Survey data. The PLI were > 1, indicating soil pollution in the two states. Between pXRF and ICP-MS, the Igeo and EF in Arizona had similar degree of contamination for most elements except Zn in garden and Pb in yard, respectively. For New York, the Igeo of As, Cu, and Zn differed by only one classification index between the two methods. The pXRF was reliable in determining As, Ba, Ca, Cu, Mn, Pb, and Zn in impacted communities. Therefore, the pXRF can be a cost-effective alternative to using ICP-MS techniques to screen soil samples for several environmentally relevant contaminants to protect environmental public health.
Subject(s)
Environmental Monitoring , Metals , Soil Pollutants , Soil , Spectrometry, X-Ray Emission , Soil Pollutants/analysis , Environmental Monitoring/methods , Spectrometry, X-Ray Emission/methods , Arizona , Metals/analysis , Soil/chemistry , New York , Reproducibility of Results , Mass Spectrometry/methods , Metals, Heavy/analysisABSTRACT
OBJECTIVES: Trace elements (TEs) are ubiquitous. TE concentrations vary among individuals and countries, depending on factors such as living area, workplaces and diet. Deficit or excessive TEs concentrations have consequences on the proper functioning of human organism so their biomonitoring is important. The aim of this project was to provide reference values for TEs concentrations in the Swiss population. METHODS: The 1,078 participants to the SKiPOGH cohort included in this study were aged 18-90 years. Their 24-h urine and/or plasma samples were analyzed by inductively coupled plasma mass spectrometry (ICP-MS) to determine 24 TEs concentrations: Ag, Al, As, Be, Bi, Cd, Co, Cr, Cu, Hg, I, Li, Mn, Mo, Ni, Pb, Pd, Pt, Sb, Se, Sn, Tl, V and Zn. Statistical tests were performed to evaluate the influence of covariates (sex, age, BMI, smoking) on these results. Reference intervals for the Swiss adult population were also defined. RESULTS: TEs concentrations were obtained for respectively 994 and 903 persons in plasma and urine matrices. It was possible to define percentiles of interest (P50 and P95) for almost all the TEs. Differences in TEs distribution between men and women were noticed in both matrices; age was also a cofactor. CONCLUSIONS: This first Swiss biomonitoring of a large TEs-panel offers reference values in plasma and in urine for the Swiss population. The results obtained in this study were generally in line with clinical recommendations and comparable to levels reported in other population-based surveys.
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BACKGROUND: Recent papers on LA-ICP-MS have reported that certain elements are transported in particulate form, others in gaseous form and still others in a combination of both upon ablation of C-based materials. These two phases display different transport behaviour characteristics, potentially causing smearing in elemental maps, and could be processed differently in the ICP which raises concerns as to accuracy of quantification and emphasizes the need for matrix-matching of external standards. This work aims at a better understanding of two-phase sample transport by evaluating the peak profile changes observed upon varying parameters such as laser energy density and wavelength. RESULTS: It is demonstrated that upon ablation of gelatin, elements are transported predominantly in particulate phase, but already at low laser energy density, a significant fraction of some elements is transported in the gaseous phase, which is even more expressed at higher energy density. This behaviour is element-specific since the ratio of the signal intensity for the analyte element transported in gas phase to the total signal intensity was 0 % for 23Na, 43 % for 66Zn and as high as 95 % for 13C using a 193 nm laser. The results also suggest an effect of the laser wavelength, as all elements show either the same or higher amount of gas phase formation upon ablating with 213 nm versus 193 nm. It was even established that elements that fully occur in particulate form upon ablation using 193 nm laser radiation are partly converted into gaseous phase when using 213 nm. SIGNIFICANCE: This work provides a thorough investigation of the underexposed phenomenon of two-phase sample transport upon ablation of biological samples upon via LA-ICP-MS. It is shown that for some elements a fraction of the ablated material is converted and transported in the gas phase, which can lead to significant smearing effects. As such, it is important to evaluate element-specific peak profiles on beforehand and, if necessary, adapt instrument settings and slow down data acquisition.
Subject(s)
Gelatin , Laser Therapy , Gases , Spectrum Analysis , Mass SpectrometryABSTRACT
Environmental Justice (EJ) communities may experience barriers that can prevent soil monitoring efforts and knowledge transfer. To address this gap, this study compared two analytical methods: portable X-ray Fluorescence Spectroscopy (pXRF, less time and costs) and Inductively Coupled Plasma Mass Spectrometry (ICP-MS, "gold standard"). Surface soil samples were collected from yards and gardens in three counties in Arizona, USA (N=124) and public areas in Troy, New York, USA (N=33). Statistical calculations, i.e., two-sample t-tests, Bland-Altman plots, and a two-way ANOVA indicated no significant difference for As, Ba, Ca, Cu, Mn, Pb, and Zn concentrations except for Ba in the two-sample t-test. Iron, Ni, Cr, and K were statistically different for Arizona soils and V, Ni, Fe and Al concentrations were statistically different for New York soils. To assess the degree of contamination, a pollution load index (PLI), enrichment factors (EF), and geo-accumulation index (Igeo) were calculated for both methods using U.S. Geological Survey soils data. The PLI were >1, indicating pollution across the two states. Between pXRF and ICP-MS, the Igeo and EF in Arizona had similar degree of soil contamination for most elements except Zn in garden and Pb in yard, respectively. In New York, the Igeo of As, Cu, and Zn differed by an order of magnitude between the two methods. The results of this study demonstrate that pXRF is a reliable method for the inexpensive and rapid analysis of As, Ba, Ca, Cu, Mn, Pb, and Zn. Thus, EJ communities may use pXRF to screen large numbers of soil samples for several environmentally relevant contaminants to protect environmental public health.
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In this study, we developed and validated an analytical method to evaluate the heavy metal elution from an active packaging material's oxygen absorber to a food simulant. Using water, 4% acetic acid, n-heptane, 20% ethanol, and 50% ethanol as food simulants, we quantified cobalt, copper, platinum, and iron with inductively coupled plasma-mass spectrometry. The method was thoroughly validated for linearity, accuracy, precision, LOD, and LOQ through inter-day and intra-day analysis repetitions. R2 values ranged from 0.9986 to 1.0000, indicating excellent linearity. The LOD values ranged from 0.00002 to 0.2190 mg/kg, and the LOQ values ranged from 0.00007 to 0.6636 mg/kg. The method's accuracy was 95.14% to 101.98%, with the precision ranging from 0.58% to 10.37%. Our results confirmed the method's compliance with CODEX standards. Monitoring the oxygen absorber revealed undissolved platinum, cobalt levels from 0.10 to 19.29 µg/kg, copper levels from 0.30 to 976.14 µg/kg, and iron levels from 0.06 to 53.08 mg/kg. This study established a robust analytical approach for evaluating the heavy metal elution from oxygen absorbers, ensuring safety in the food industry.
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Environmental monitoring programs that target fish tissues for selenium (Se) analysis present unique sampling and analytical challenges. Selenium monitoring programs ideally focus on egg/ovary sampling but frequently sample multiple tissues with varying lipid content, often target small-bodied fish species because of their small home ranges, and require reporting in units of dry weight. In addition, there is a growing impetus for nonlethal tissue sampling in fish monitoring. As a result, Se monitoring programs often generate low-weight tissue samples of varying lipid content, which challenges analytical laboratories to quantify tissue Se concentrations accurately, precisely, and at desired detection limits. The objective of the present study was to stress-test some conventional analytical techniques used by commercial laboratories in terms of their ability to maintain data quality objectives (DQOs) in the face of sample weight constraints. Four laboratories analyzed blind a suite of identical samples, and data were compared against a priori DQOs for accuracy, precision, and sensitivity. Data quality tended to decrease with decreasing sample weight, particularly when samples were less than the minimum weights requested by the participating laboratories; however, effects of sample weight on data quality were not consistent among laboratories or tissue types. The present study has implications for accurately describing regulatory compliance in Se monitoring programs, highlighting some important considerations for achieving high data quality from low-weight samples. Environ Toxicol Chem 2023;42:2119-2129. © 2023 SETAC.
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Rationale: A simple, sensitive, reliable, validated, inductively coupled plasma mass spectrometric method for the determination of aluminium and magnesium using a simple common microwave-assisted digestion sample preparation technique for a few commonly used formulations was developed and validated according to International Conference on Harmonization Q3D and the United States Pharmacopeia general chapter <232> and <233>. The following pharmaceutical dosage forms were considered for estimation of aluminium and magnesium: Alumina, magnesia simethicone oral suspension, Alumina, magnesia simethicone chewable tablets, alumina and magnesia oral suspension, alumina and magnesium carbonate oral suspension. Methods: The methodology included optimizing a common microwave assisted digestion method, selecting the isotopes, choosing the measurement technique, and designating internal standards. The finalized microwave assisted procedure was a two-step program where in the first step the samples were ramped for 10â min to a temperature of 180â °C and hold for 5â min followed by ramping for 10â min to a temperature of 200â °C and hold for 10â min. Magnesium (24Mg) and aluminium (27Al) isotopes were finalized, internal standard assigned for both the isotopes was yttrium (89Y) with Helium (kinetic energy discrimination-KED) as the measuring mode. System suitability was run before initiating analysis to ensure that system performance was consistent. Results: Analytical validation parameters like specificity, linearity (from 25% to 200% of sample concentration), the detection limit and the limit of quantification were established. For all these dosage forms, the method's precision was demonstrated by analyzing the percentage relative standard deviation for six injections. Accuracy was established from 50% to 150% of instrument working concentration (J-levels) for aluminium and magnesium for all the formulations and was found to be within the range of 90-120%. Conclusion: This common analysis method, along with the common microwave-digestion technique applies to numerous types of matrices for a finished dosage form with aluminium and magnesium.
Subject(s)
Aluminum , Magnesium , Microwaves , Magnesium Oxide , Simethicone , Aluminum Oxide , Pharmaceutical Preparations , Isotopes , DigestionABSTRACT
Forensic science practitioners are often called upon to attribute crimes using trace evidence, such as explosive remnants, with the ultimate goal of associating a crime with a suspect or suspects in order to prevent further attacks. The explosive charge is an attractive component for attribution in crimes involving explosives as there are limited pathways for acquisition. However, there is currently no capability to link an explosive charge to its source via post-blast trace residues using isotope ratios or trace elements. Here, we sought to determine if pre-blast attribution signatures are preserved after detonation and can be subsequently recovered and detected. A field study was conducted to recover samples of post-blast explosives from controlled detonations of ammonium nitrate-aluminum (AN-Al), which were then analyzed via isotope ratio mass spectrometry (IRMS) and inductively coupled plasma-mass spectrometry (ICP-MS) for quantitation and profiling of isotopes ratio and trace element signatures, respectively. Oxygen and nitrogen isotope ratios from AN-Al yielded some of the most promising results with considerable overlap within one standard deviation of the reference between the spreads of pre- and post-blast data. Trace element results from AN-Al support the findings in the isotope ratio data, with 26 elements detected in both pre- and post-blast samples, and several elements including B, Cd, Cr, Ni, Sn, V, and Zn showing considerable overlap. These preliminary results provide a proof-of-concept for the development of forensic examinations that can attribute signatures from post-blast debris to signatures in pre-blast explosive materials for use in future investigations.
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BACKGROUND & AIMS: Parenteral nutrition (PN) can lead to high or even toxic exposure to aluminum (Al). We aimed to quantify concentrations of Al and other chemical elements of all-in-one (AIO) PN admixtures for adults prepared from commercial multichamber bags (Olimel® 5.7%, Omegaflex® special, SmofKabiven®, all with and without electrolytes) and vitamin and trace element additives over a 48-h period. Secondly, we determined the level of Al contamination resulting from admixing and infusion set use. METHODS: We used dynamic reaction cell and kinetic energy discrimination inductively coupled plasma mass spectrometry (ICP-MS) to quantify Al, arsenic (As), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), magnesium (Mg), manganese (Mn), molybdenum (Mo), nickel (Ni), antimony (Sb), selenium (Se), tin (Sn), vanadium (V), and zinc (Zn) in AIO PN admixtures. We extracted samples for analysis via the bag injection ports and infusion sets over a 48-h period after admixing. We compared the measured Al concentrations of AIO PN admixtures with calculated values based on the measured concentrations of individual chamber contents and additives. RESULTS: Mean (standard deviation) baseline Al concentrations in AIO PN admixtures ranged from 10.5 (0.5) to 59.3 (11.4) µg/L and decreased slightly over the 48 h (estimate [standard error] -0.09 [0.02] µg/L/hour, p <0.001). Thus, certain products exceeded the widely accepted limit of 25 µg/L. There was no significant difference in Al concentrations between samples extracted via the bag injection ports or infusion sets (p = 0.33), nor between measured and calculated Al concentrations of AIO PN admixtures (p = 0.91). CONCLUSION: Because certain commercially available PN admixtures for adults proved to contain excessively high levels of Al in our study, regulations and corresponding quality requirements at the authority level (e.g., Pharmacopoeia and regulatory authorities) are urgently required. Our results showed that the PN handling process (admixing and supplementing additives) or the materials of the infusion set did not lead to additional Al contamination to any extent. Moreover, calculated Al concentrations of AIO PN admixtures derived from individual chamber contents and additives are valid.
Subject(s)
Aluminum , Trace Elements , Adult , Humans , Trace Elements/analysis , Manganese/analysis , Copper , Parenteral NutritionABSTRACT
Uranium (U) and Thorium (Th) concentrations are normally low in the water (<30 and 5 ng mL-1, respectively). However, we performed a direct analysis of 232Th, 234U, 235U and 238U in cenote water from the Yucatán Peninsula using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) as a rapid response technique to perform environmental radioactivity monitoring. Water samples were collected in 2021 from the cenotes and these were certificated by zones (PYNO, PYNE and PYSE) and monitoring depth [surface water (n = 52) and depth water (n = 48)]. Moreover, physicochemical parameters such as pH, electrical conductivity (EC), total dissolved solids (TDS), and temperature were measured in situ. Results obtained were total U and Th levels below permissible for human consumption. However, physicochemical parameters must be considered before use because it is outside the permissible limits in most cenotes. The median concentration value for 234U, 235U, 238U and 232Th in surface + depth water were 0.0001 ng mL-1, 0.0130 ng mL-1, 1.76 ng mL-1, and 0.062 ng mL-1, respectively. In addition, isotopic ratio of 235U/238U in surface + depth water was 0.00730. In addition, the PYNO zone showed a correlation between 232Th with EC and TDS. The PYSE zone showed a correlation between 232Th and temperature, and 235U/234U with pH, while PYEN did not show correlations. In conclusion, the first time evaluated U isotope concentrations and isotopic ratios of U and 232Th in cenote water from the Yucatán Peninsula, where U and Th concentrations were found below the permissible limits mentioned by guidelines for drinking-water quality. The average of 235U/238U is similar to isotopic ratios in "natural" water.
Subject(s)
Thorium , Uranium , Humans , Isotopes/analysis , Mexico , Thorium/analysis , Uranium/analysisABSTRACT
Introduction: evaluating the sodium content of staple foods is essential for implementing a salt reduction strategy. In Morocco, bread is a major contributor to sodium intake. However, currently few studies have been carried out to assess the salt content in bread. Our study aimed to estimate the sodium and salt content of white bread available in artisanal and industrial bakeries in the twelve regions of Morocco. Methods: it is a cross-sectional study of the sodium content of white bread available for sale in artisanal and industrial bakeries in Morocco (N=120). Inductively coupled plasma mass spectrometry (ICP-MS) was used to quantify the sodium content of the bread. The percentage of samples meeting the recommendations and bread contribution to the daily salt intake was calculated. Results: the results of our study show that the mean levels of sodium and salt added to bread samples were 5.7 ± 1.5 g/Kg and 14.5 ± 3.7 g/Kg, respectively. With an average of 4.4 ± 0.5 g/Kg and 11.2 ± 1.2 g/Kg for artisanal bread and an average of 7.0 ± 0.8 g/Kg and 17.8 ± 2.1 g/Kg for industrial bread, respectively. Daily salt intake from bread consumption (500 g/d/person) is estimated at 5.6 g/d (52.8% of total salt intake) for artisanal bread and 8.9 g/d (84% of total salt intake) for industrial bread. Conclusion: bread salt content in Morocco exceeds the recommended threshold of the national federation of bakery and pastry and health authorities. Further efforts are necessary to increase knowledge and awareness of bakers and to teach them how to reduce salt content without affecting the flavor and the quality of their products.
Subject(s)
Bread , Sodium Chloride, Dietary , Cross-Sectional Studies , Humans , Mass Spectrometry , Sodium , Sodium ChlorideABSTRACT
Recently studies based on limited sample sizes procured from minor hop growing regions have speculated that the elemental profile of hops can possibly be used to authenticate the origin of a hop because changes in hop elemental profiles were realted to growing region and that these changes might also be related to beer quality. To explore this further, 205 hop samples (i.e. 203 whole cone hops and 2 pelletized samples) compromised of 19 varieties were procured from the major hop growing regions (i.e. the U.S. and Germany). These hops were digested with microwave digestion and analyzed for 25 elements using ICP-MS. Hops from most of the U.S. regions (mainly WA) had vastly different elemental profiles than hops from Germany. German hops had significantly lower concentrations for most of the elements except for Cu and K. Interestingly, high alpha varieties had significantly different elemental profiles than varieties bred for aroma purposes. Dry-hopping trials were then performed in an ale and a lager with the hops that had significantly different elemental profiles. Although heavy metals were extracted from hops into beer, at the 5 g/L dry-hopping load used in this study, beer concentrations of these elements remained below regulated water quality standards set by Germany, the U.S., and Canada. Based on electron paramagnetic resonance, dry-hopping had an antioxidant impact on beer regardless of the original elemental profile of the hops which was correlated to hop polyphenol and α/ ß - acid concentrations. Overall these results highlight that many factors including location have the potential to influence the elemental profile of hops and that changes in the elemental profiles of hops can be related to beer quality.
Subject(s)
Humulus , Beer/analysis , Germany , Odorants/analysis , Plant BreedingABSTRACT
In this study, the content of five heavy metals(Pb, Cd, As, Hg, and Cu) in 59 batches of Lonicerae Japonicae Flos(LJF) medicinal materials and pieces were determined by inductively coupled plasma mass spectrometry(ICP-MS). The health risk assessment was processed using the maximum estimated daily intake(EDI), target hazard quotients(THQ), and carcinogenic risks(CR) assessment models. With reference to the limit standard for heavy metal content in LJF specified in 2020 edition of Chinese Pharmacopoeia, five batches produced in Hebei were found to contain excessive Pb, and the remaining 54 batches met the specifications, with the unqualified rate of 8.47%. Comparative analysis of heavy metal content in LJF samples from three different producing areas, namely Shandong, Henan, and Hebei showed that the levels of Pb, As, and Hg in LJF from Hebei were significantly higher than those from Henan and Shandong. The samples produced in Shandong contained the highest content of Cd. The samples from Hebei contained the highest content of Cu while those from Shandong had the lowest content of Cu. As demonstrated by health risk assessment based on the EDI, THQ and CR models, these 59 batches of LJF samples did not cause significant health hazards for the exposed population, and there was no potential non-carcinogenic or carcinogenic risk. In conclusion, a few of LJF samples contained excessive heavy metals, so some measures, including controlling production environment, cultivating management mode, and optimizing processing methods, should be taken for ensuring the medication safety of LJF.
Subject(s)
Drugs, Chinese Herbal , Mercury , Metals, Heavy , Environmental Pollution/analysis , Mercury/analysis , Mercury/toxicity , Metals, Heavy/analysis , Metals, Heavy/toxicity , Risk AssessmentABSTRACT
Compared to the classical chemicals, nanoparticles (NPs) exhibit unique properties, which lead to challenges in sample preparation and analysis. Fractionation techniques and, in particular, hollow fiber flow field flow fractionation (HF5) have recently become popular in the characterization and quantification of nanomaterials, because of their fine fractionation capability in the nanoscale-range. When dealing with NPs, a great drawback during fractionation is the loss of particles in the fractionation devices, tubing and connectors. There is a need for studies to systematically explore and assess the quality of the fractionation process. A combination of two complementary mass-based setups was used to determine particle loss in HF5. Inductively coupled plasma mass spectrometry (ICP-MS) enabled the estimation of recovery rates for NPs after HF5 separation. Reciprocally, laser ablation ICP-MS (LA-ICP-MS) permitted the evaluation of particles retained on the hollow fiber. 15 nm Au-NPs in different concentrations were evaluated in this study and showed a recovery level for Au-NPs of 50 - 65% based on the applied concentrations after a complete HF5 separation run. Detection of sample deposition on the hollow fiber by LA-ICP-MS indicated a sample loss of about 8%. These findings are important for experiments relying on fractionation of low concentrated nanoparticulate samples.
Subject(s)
Fractionation, Field Flow , Nanoparticles , Humans , Mass Spectrometry , Spectrum AnalysisABSTRACT
In this study, the content of five heavy metals(Pb, Cd, As, Hg, and Cu) in 59 batches of Lonicerae Japonicae Flos(LJF) medicinal materials and pieces were determined by inductively coupled plasma mass spectrometry(ICP-MS). The health risk assessment was processed using the maximum estimated daily intake(EDI), target hazard quotients(THQ), and carcinogenic risks(CR) assessment models. With reference to the limit standard for heavy metal content in LJF specified in 2020 edition of Chinese Pharmacopoeia, five batches produced in Hebei were found to contain excessive Pb, and the remaining 54 batches met the specifications, with the unqualified rate of 8.47%. Comparative analysis of heavy metal content in LJF samples from three different producing areas, namely Shandong, Henan, and Hebei showed that the levels of Pb, As, and Hg in LJF from Hebei were significantly higher than those from Henan and Shandong. The samples produced in Shandong contained the highest content of Cd. The samples from Hebei contained the highest content of Cu while those from Shandong had the lowest content of Cu. As demonstrated by health risk assessment based on the EDI, THQ and CR models, these 59 batches of LJF samples did not cause significant health hazards for the exposed population, and there was no potential non-carcinogenic or carcinogenic risk. In conclusion, a few of LJF samples contained excessive heavy metals, so some measures, including controlling production environment, cultivating management mode, and optimizing processing methods, should be taken for ensuring the medication safety of LJF.
Subject(s)
Drugs, Chinese Herbal , Environmental Pollution/analysis , Mercury/toxicity , Metals, Heavy/toxicity , Risk AssessmentABSTRACT
ObjectiveTo obtain content characteristics of inorganic elements in Scutellariae Radix (aged 1-4 years), and to explore the feasibility of identifying the growth years of Scutellariae Radix based on characteristic spectrum of inorganic elements combined with chemometric models. MethodAfter microwave digestion, the contents of Mn, Zn, Ca, Fe, Mg, Na, K, Cr, Cu, Se, As, Cd, Hg, Pb and Ni in 21 batches of Scutellariae Radix were determined by inductively coupled plasma atomic emission spectrometry (ICP-OES) and inductively coupled plasma mass spectrometry (ICP-MS). Meanwhile, characteristic spectrum of inorganic elements in samples was drawn. The identification model was constructed to discriminate the growth years of Scutellariae Radix based on the combination of principal component analysis (PCA), Fisher discriminant function and support vector machine (SVM). ResultThe contents of Mn (7.79-36.48 μg·g-1), Zn (10.12-31.43 μg·g-1), Cu (6.38-17.20 μg·g-1), K (2.98-13.89 μg·g-1), Mg (3.45-7.78 μg·g-1) and Ca (2.32-7.09 μg·g-1) in Scutellariae Radix were detected by ICP-OES and ICP-MS, and their contents increased with the prolongation of growth years. PCA results showed that Cu, Ni, Cd, Na, Mg, Fe, Ca, Zn, Mn and Hg were characteristic elements of Scutellariae Radix. Samples with different years could be divided into four categories in the spatial characteristic diagram of Fisher discriminant analysis. The correct rate of SVM model for identifying the growth years of samples was 95.2%. ConclusionThis established method is accurate and rapid for discriminating the growth years of Scutellariae Radix, which can provide reference for the identification of other Chinese medicinal materials. It is suggested that some elements should be considered as indexes in subsequent construction of the quality evaluation system of Scutellariae Radix.
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BACKGROUND: The pan-European human biomonitoring initiative HBM4EU targets the harmonization of human biomonitoring (HBM) procedures and data for both environmental and occupational exposure, including chromium. The determination of chromium in urine (U-Cr), plasma (P-Cr) and whole blood (WB-Cr) is a common HBM application in employees occupationally exposed to chromium (VI) compounds. METHODS: European laboratories which have registered as candidate laboratories for chromium analysis within HBM4EU were invited to participate in a quality assurance/qualitycontrol (QA/QC) programme comprising interlaboratory comparison investigations (ICI) for the parameters U-Cr, P-Cr and WB-Cr. Participating laboratories received two samples of different concentrations in each of four rounds and were asked to analyse the samples using their standard analytical procedure. The data were evaluated by the Z-score approach and were reported to the participants after each round. RESULTS: The majority of the 29 participating laboratories obtained satisfactory results, although low limits of quantification were required to quantify chromium concentrations in some of the ICI materials. The robust relative standard deviation of the participants' results (study RSDR) obtained from all ICI runs ranged from 6 to 16 % for U-Cr, 7-18 % for P-Cr and 4-47 % for WB-Cr. The application of both inductively coupled plasma mass spectrometry (ICP-MS) and electrothermal atomic absorption spectrometry (EAAS) appeared appropriate for the determination of chromium in urine, plasma and whole blood with regard to occupational exposure levels. CONCLUSION: This QA/QC programme succeeded in establishing a network of laboratories with high analytical comparability and accuracy for the analysis of chromium across Europe.
Subject(s)
Biological Monitoring , Occupational Exposure , Chromium/analysis , Environmental Monitoring , Humans , Occupational Exposure/analysis , Spectrophotometry, AtomicABSTRACT
Selenium (Se) is a vital micronutrient with widespread biological action but leads to toxicity when taken in excessive amounts. The biological benefits of Se are mainly derived from its presence in active sites of selenoproteins such as glutathione peroxidase (GPx). An enzyme whose role is to protect tissues against oxidative stress by catalysing the reduction of peroxidase responsible for various forms of cellular damage. The benefits of Se can be harvested when proper regulations of its intake are used. In South Africa, Se distribution in people's diets and animals are low with socio-economic factors and heterogeneous spread of Se in soil throughout the country playing a significant role. The possible causes of low Se in soils may be influenced by underlying geological material, climatic conditions, and anthropogenic activities. Sedimentary rock formations show higher Se concentrations compared to igneous and metamorphic rock formations. Higher Se concentrations in soils dominates in humid and sub-humid areas of South Africa. Furthermore, atmospheric acid deposition dramatically influences the availability of Se to plants. The studies reviewed in this article have shown that atomic absorption spectroscopy (AAS) is the most utilised analytical technique for total Se concentration determination in environmental samples and there is a lack of speciation data for Se concentrations. Shortcomings in Se studies have been identified, and the future research directions of Se in South Africa have been discussed.
Subject(s)
Selenium , Trace Elements , Animals , Glutathione Peroxidase , Micronutrients , South Africa , Selenoproteins , Soil/chemistryABSTRACT
Aluminum enters the body primarily through diet or occupational exposure, and is cleared through urine. However, this trace element may accumulate and cause toxicity in subjects with renal insufficiency, and even in dialysis patients. The mechanism of aluminum toxicity is related to increased oxidative and inflammatory stress, iron and calcium dyshomeostasis, or cholinergic dysregulation, among other. A review was conducted on the specimens and analytical methods used to determine aluminum in biological specimens and dialysis water. This paper describes the most relevant aspects related to quality assurance. This is a practical guideline for the development and implementation of a reliable method for determination of aluminum in the clinical laboratory. Serum aluminum is the main biomarker of toxicity. For cases of chronic exposure, urine testing is recommended. At present, inductively coupled plasma mass spectrometry (ICP-MS) is the gold-standard determination method, since it has been proven to have the best quantification limits, selectivity and robustness. Clear recommendations are provided in relation to the specimens used for aluminum determination. Relevant pre-analytical, analytical, and post-analytical considerations are also presented.