Inductively Coupled Plasma MS Research Articles

Study of the Unique Characteristics of Multi-Elements of the Wild Astragali Radix from Shanxi Province by Inductively Coupled Plasma Mass Spectrometry.

Astragali Radix (AR) is widely used because of its dual use in medicine and food. Wild Astragali Radix from Hunyuan county of Shanxi province in China is accepted as a geo-authentic medicine with high quality and good medicinal effects. Multi-elements of Astragali Radix partially reflect its efficacy and safety. However, there has been no systemic research about the elemental analysis of geo-authentic Astragali Radix until now. In this paper, multi-elemental profiling of Astragali Radix from Gansu, Jilin, Inner Mongolia, Shaanxi and Shanxi provinces in China was carried out. A microwave digestion coupled with inductively coupled plasma-MS (ICP-MS), principal component analysis (PCA), and partial-least square-discriminate analysis (PLS-DA) were used for analysis of the unique elemental accumulation ability of Shanxi wild AR. Compared to the samples from Gansu, Jilin, Inner Mongolia, Shaanxi provinces, and the cultivated samples from Shanxi, for 53 stably detected elements, the concentrations of most elements (Ba, Cs, Ga, La, Pr, and so on) were significantly higher while a few (Cd, Cu, P, W and Zn) were significantly lower in wild Astragali Radix from Shanxi. After binary logistic regression, combinational variable Ba-P was found to be a good marker to distinguish wild Astragali Radix of Shanxi province from the samples with other origins, and the total positive prediction probability of the test samples, both bought from the market and gathered from their original field, could reach 93.8% through external validation using the model. Multi-elemental analysis coupled with PCA, PLS-DA, nonparametric analysis and binary logistic regression can be a good tool for the identification of wild Astragali Radix from Shanxi province. An ICP-MS method was developed and validated for multi-elements. Fifty-three elements in Astragali Radix from samples with different origins were compared. The wild Astragali Radix from Shanxi had unique elemental characteristics. Combinational variable Ba-P is a good marker to identify wild AR from Shanxi.

Speciation of metals in indigenous plants growing in post-mining areas: Dihydroxynicotianamine identified as the most abundant Cu and Zn ligand in Hypericum laricifolium

Ag, As, Cu, Pb and Zn were found to be the principal metallic contaminants of a post-mining area of Peru (Hualgayoc, Cajamarca). Study of metal distribution amongst roots, stems, and leaves of four indigenous hypertolerant plant species, Arenaria digyna, Puya sp., Hypericum laricifolium, Nicotiana thyrsiflora indicated significant translocation of Zn (0.6 < TF ≤ 10.0) and Cu (0.4 < TF ≤ 6.5) into aerial plant organs and substantial water-extractable fraction (20–60%) of these metals, except for A. digyna (root and stems). A study of the metal speciation by ultrahigh-performance size-exclusion (fast-SEC) and hydrophilic ion interaction (HILIC) liquid chromatography with dual ICP (inductively coupled plasma) and electrospray (ESI) Orbitrap MS detection revealed the presence of nicotianamine and deoxymugineic acid copper and zinc complexes in roots, stem and leaves of N. thyrsiflora and Puya sp., and nicotianamine alone in A. digyna. A previously unreported compound, dihydroxy-nicotianamine was identified as the most abundant Cu and Zn ligand in H. laricifolium. The presence of arsenobetaine and an arsenosugar was confirmed by ESI MS. Ag and Pb were hardly translocated to leaves and were found as high molecular species; one of the Pb-containing species co-eluted in fast-SEC-ICP MS with rhamnogalacturonan-II-Pb complex commonly found in in the walls of plants.

MASS SPECTROMETRY-BASED TECHNIQUES FOR DIRECT QUANTIFICATION OF HIGH IONIZATION ENERGY ELEMENTS IN SOLID MATERIALS-CHALLENGES AND PERSPECTIVES.

The determination of nonmetals, first of all, the most electronegative ones-nitrogen, oxygen, fluorine, chlorine, and bromine, poses the highest challenge for element analysis. These elements are characterized by high reactivity, volatility, high ionization energy, and the absence of intensive spectral lines in the optical spectral range. Conventional techniques of their quantification include considerable "wet chemistry" stages so the application of these techniques for the solid sample is highly laborious and prone to uncontrollable uncertainties. Additionally, current development in material science and other areas requires the quantification of the elements at lower levels with good sensitivity. Owing to their robustness and flexibility, mass spectrometry techniques provide vast possibilities for the quantification, spatial and isotopic analysis, including the solutions for direct analysis of solids. The current review focuses on the application of major mass spectrometric techniques for the quantification of N, O, F, Cl, and Br in solid samples. The following techniques are mainly considered: thermal ionization mass spectrometry (TIMS), isotope-ratio MS (IRMS), secondary ion MS (SIMS), inductively coupled plasma MS (ICP-MS), and glow discharge MS (GDMS); as the most accessible and widely applied for the purpose. General ionization issues, advantages, limitations, and novel methodological solutions are discussed. © 2020 John Wiley & Sons Ltd.

Sniffing out cocoa bean traits that persist in chocolates by PTR-MS, ICP-MS and IR-MS

The cocoa botanical and geographical origin and the primary processing steps applied by cocoa farmers at the beginning of the supply chain influence the chemical compositional traits of the cocoa beans. These features are carried along the supply chain as intrinsic markers up to the final products. These intrinsic markers could be used for tracking and tracing purposes. In this study, we examined the retention and loss of compositional signatures from cocoa beans to chocolates. Volatile, elemental and stable isotope signatures of cocoa beans of 10 different origins and 11 corresponding chocolates were determined by high sensitivity-proton transfer reaction-mass spectrometry (HS-PTR-MS), inductively coupled plasma-MS (ICP-MS) and isotope ratio-MS (IR-MS), respectively. The volatile fingerprints provided mostly information on the origin and primary processing traits of the raw cocoa beans in the chocolates. Volatile compounds that are relevant markers include: acetic acid (m/z 61), benzene (m/z 79), pyridine (m/z 80), 2-phenylethanol (m/z 123), and maltol (m/z 127). On the other hand, the elemental and stable isotope characteristics are more indicative of the cocoa content and added ingredients. Possible elemental markers for cocoa origin include Fe, Cr, and Cd. VOCs appear to be the most robust markers carried from cocoa beans to chocolates of the groups examined. This provides the potential for track and trace of cocoa beans from farm to chocolates.

Identification of a selective manganese ionophore that enables nonlethal quantification of cellular manganese

Available assays for measuring cellular manganese (Mn) levels require cell lysis, restricting longitudinal experiments and multiplexed outcome measures. Conducting a screen of small molecules known to alter cellular Mn levels, we report here that one of these chemicals induces rapid Mn efflux. We describe this activity and the development and implementation of an assay centered on this small molecule, named manganese-extracting small molecule (MESM). Using inductively-coupled plasma-MS, we validated that this assay, termed here "manganese-extracting small molecule estimation route" (MESMER), can accurately assess Mn in mammalian cells. Furthermore, we found evidence that MESM acts as a Mn-selective ionophore, and we observed that it has increased rates of Mn membrane transport, reduced cytotoxicity, and increased selectivity for Mn over calcium compared with two established Mn ionophores, calcimycin (A23187) and ionomycin. Finally, we applied MESMER to test whether prior Mn exposures subsequently affect cellular Mn levels. We found that cells receiving continuous, elevated extracellular Mn accumulate less Mn than cells receiving equally-elevated Mn for the first time for 24 h, indicating a compensatory cellular homeostatic response. Use of the MESMER assay versus a comparable detergent lysis-based assay, cellular Fura-2 Mn extraction assay, reduced the number of cells and materials required for performing a similar but cell lethality-based experiment to 25% of the normally required sample size. We conclude that MESMER can accurately quantify cellular Mn levels in two independent cells lines through an ionophore-based mechanism, maintaining cell viability and enabling longitudinal assessment within the same cultures.

Quality variation and standardization of black pepper (Piper nigrum): A comparative geographical evaluation based on instrumental and metabolomics analysis

Black pepper (Piper nigrum; BP), known as the 'king of spices', imported from various countries is widely available in Saudi Arabian markets, as its demand as a food as well as a medicine for minor ailments is increasing in the country. However, there is a lack of appropriate information regarding these samples in terms of quality variation and standardization. We thus aimed to evaluate the quality and standardize the BP sample with respect to its physicochemical characters, active principle variation [i.e. piperine (PPN)], toxicity, and biological activity. The main focus is to validate whether any difference exists in the quality and quantity of active principle in these samples. For this purpose, physicochemical (chemical tests and ash values) and instrumental analyses [accelerated solvent extraction (ASE), ultra-high-pressure liquid chromatography (UHPLC)-diode array detector, infrared (IR), nuclear magnetic resonance (NMR), and inductively coupled plasma-MS (ICP-MS)] and biological evaluation {in vitro antioxidant activity [2,2-diphenyl-1-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)] and cytotoxicity assay} were performed. An extract yield (g) with %recovery of 2.26 ± 4.24 (11.3) was obtained for the Vietnamese sample, using a fast and rapid method of extraction (ASE). These values were 1.22 ± 2.64 (6.1) and 0.75 ± 1.69 (3.75) for the Pakistani and Indian samples. Physicochemical tests revealed the presence of flavonoids and phenolic compounds in all samples; however, in the Vietnamese sample a low amount of total, acid-insoluble, and high water-soluble ash value was noted. IR and NMR was applied to further standardize the samples. Results of ICP-MS analysis showed a high amount of macronutrients and micronutrients in the samples tested while UHPLC analysis revealed a high amount of PPN (ng/mL) in the Pakistani sample (1,362,614.09); these values were 1,051,848.04 and 768,512.81 for the Vietnamese and Indian samples, respectively. In vitro antioxidant and cytotoxicity activities revealed higher potential for the Vietnamese sample. The samples were properly standardized and effectively differentiated in terms of quality and biological activities using a fast and reliable method, however it certainly does not mean that a particular geographical region is more better or productive in terms of herbal products.

Characterization of quantum dots in cancer cytosol using ICP-MS-based combined techniques

Knowledge of the intracellular behavior of quantum dots (QDs), which encompasses the antiproliferative effect on living cells, is still limited. For this reason, the transformations of CdSeS/ZnS-based QDs in cancer cytosol were examined using capillary electrophoresis (CE) and high-performance liquid chromatography (HPLC) hyphenated with inductively coupled plasma MS (ICP-MS). CE-ICP-MS method revealed the dose- and time-dependent speciation changes of QDs in the cytosol, while HPLC-ICP-MS (in the size-exclusion chromatography mode) allowed further characterization of the resulting Cd species. In such an appraisal, the decent CE advantage of high resolution is well complemented by higher sensitivity of HPLC (LOD 4.0 × 10−10 and 5.4 × 10−12 mol/L Cd, respectively). Additionally, the influence of serum protein corona on the surface of QDs on their uptake by Hep G2 cancer cells was investigated by direct ICP-MS analysis that revealed that the conjugated proteins greatly reduce the particle internalization.

Understanding Electrolyte Decomposition of Graphite/NCM811 Cells at Elevated Operating Voltage

Cells containing LiNixCoyMn1-x-yO2 (NCM) materials with very high nickel content suffer from cathode material degradation upon cycling, especially when operating these cells at higher voltage. While the cathode particle degradation is a problem other issues contribute to electrochemical performance loss. Graphite/LiNi0.8Co0.1Mn0.1O2 cells have been cycled to different upper cutoff voltages and investigated with electrochemical impedance spectroscopy (EIS), gas analysis with online electrochemical mass spectroscopy (OEMS), nuclear magnetic resonance (NMR) spectroscopy, gas chromatography with MS (GCMS) and inductively coupled plasma MS (ICP-MS). Increased gas evolution was observed when the upper cutoff voltage was increased from 4.2 to 4.6 V. An increase in O2 evolution upon cycling as well as an increase of CO2 upon increasing the voltage, have been observed. More electrolyte decomposition products are observed on the anode for cells cycled to higher voltage. An increased amount of nickel has been detected on the graphite electrode in accordance with an increased reaction of the cathode surface with the electrolyte leading to transition metal dissolution. Finally, an increase in carbonate solvent transesterification products has been observed.

Characterizing activation mechanisms and binding preferences of ruthenium metallo-prodrugs by a competitive binding assay

The activation mechanisms and reactivity of ruthenium metallo-prodrug lead structures were investigated in detail using capillary zone electrophoresis mass spectrometry (CZE–MS) in a time-dependent manner and by exposing to a protein/oligonucleotide mixture. The competitive assays were performed with sodium trans-[RuCl4(HInd)2] where Hind=indazole (NKP-1339), [(η6-p-cymene)RuCl2(pta)], where pta=1,3,5-triaza-7-phosphaadamantane (RAPTA-C) and [(η6-biphenyl)RuCl(1,2-ethylenediamine)]PF6 (RM175). Molecular and quantitative information on binding preferences was obtained by coupling CZE to electrospray ionization MS (ESI-MS) and inductively coupled plasma MS (ICP-MS), respectively. A score system is presented that ranks the binding preferences of Ru complexes with nucleotides and demonstrated the following trend of decreasing selectivity after 24h: RM175 (0.89)>RAPTA-C (0.78)>NKP-1339 (0.40). As expected, the organometallic drug candidates RM175 and RAPTA-C underwent a halido/aqua ligand exchange reaction at the metal center and showed distinct reactivity towards the biomolecules. In particular, the protein/DNA binding sites of RAPTA-C in a mixture of protein (ubiquitin) and oligonucleotide (5′-dATTGGCAC-3′) were located at single-amino acid and single-nucleotide resolution, respectively. Activated RAPTA-C bound selectively to Met1, adenine and cytosine in this setting, which contrasts with the selectivity of RM175 for guanine. Finally, activation products of NKP-1339 were detected corresponding to RuII(Hind)2 fragments coordinated to the oligonucleotide, which represents one of the few examples of a directly observed RuII adduct.

Low‐Generation Polyamidoamine Dendrimers as Drug Carriers for Platinum(IV) Complexes

An unsymmetrically carboxylated platinum(IV) analogue of oxaliplatin was coupled to low‐generation polyamidoamine dendrimers (PAMAM) with amino‐terminated surfaces [generations two (G‐2) and four (G‐4)]. 1D and 2D diffusion NMR spectroscopy and high‐resolution HPLC–MS/MS were used to characterise the platinum complexes and drug–dendrimer conjugates. The average loads of platinum(IV) complex per dendrimer were determined by inductively coupled plasma MS (ICP‐MS), and maximum loads of 38 % (six platinum units per dendrimer molecule) for the smaller G‐2 and 34 % (22 platinum units per dendrimer molecule) for G‐4 were obtained. As a result of this loading, the average diameters increased from 26 to 34 Å (30 %, G‐2) and from 46 to 63 Å (38 %, G‐4). The in vitro cytotoxicities of the free platinum(IV) complex, the complex‐loaded dendrimers and the free PAMAM analogues G‐2 and G‐4 were evaluated in the cisplatin‐sensitive ovarian cell line CH1/PA1 as well as in rather cisplatin‐insensitive colon (SW480) and lung (A549) carcinoma cells by 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT) assays. Although the free platinum(IV) compound displayed a rather moderate activity, the drug–dendrimer complexes showed load‐ and size‐dependent behaviour with IC50 values down to the low‐nanomolar range. In the cisplatin‐insensitive cell lines, the benefit of this platinum load primarily consists of added cytostatic rather than cytocidal effects, on the basis of the results from annexin V/PI (PI = propidium iodide) assays for apoptosis/necrosis induction.

Hydrolytic Stability and Hydrogen Peroxide Activation of Zirconium‐Based Oxoclusters

AbstractThe hydrolytic stability of [Zr6(OH)4O4{O(O)CC(CH3)=CH2}12] (Zr6), and [Zr6O4(OH)4{O(O)CCH2CH=CH2}12]2·6[CH2=CHCH2C(O)OH] (Zr12) oxoclusters in different environments was thoroughly investigated by FTIR, Raman, and X‐ray photoelectron spectroscopy (XPS). Specific information about the local structures around the Zr centers during the stability tests was achieved by in situ extended X‐ray absorption fine structure (EXAFS) measurements, and the exact compositions were determined by inductively coupled plasma MS (ICP‐MS) and elemental analysis. By this multidimensional spectroscopic approach, an overview on the structures formed after different treatments could be gained. The stability of the oxoclusters was then investigated in the presence of hydrogen peroxide, and the formation of peroxo–metal complexes was detected. Thus, a kinetic study was performed in acetonitrile to evaluate the performances of the oxoclusters as oxygen transfer catalysts. The oxidation of methyl p‐tolyl sulfide to the corresponding sulfoxide and sulfone was chosen as a model reaction; in some cases, an interesting selectivity towards the formation of the sulfone was found over more than 4700 catalytic cycles.

Current role of ICP-MS in clinical toxicology and forensic toxicology: a metallic profile.

As metal/metalloid exposure is inevitable owing to its omnipresence, it may exert toxicity in humans. Recent advances in metal/metalloid analysis have been made moving from flame atomic absorption spectrometry and electrothermal atomic absorption spectrometry to the multi-elemental inductively coupled plasma (ICP) techniques as ICP atomic emission spectrometry and ICP-MS. ICP-MS has now emerged as a major technique in inorganic analytical chemistry owing to its flexibility, high sensitivity and good reproducibility. This in depth review explores the ICP-MS metallic profile in human toxicology. It is now routinely used and of great importance, in clinical toxicology and forensic toxicology to explore biological matrices, specifically whole blood, plasma, urine, hair, nail, biopsy samples and tissues.

Europium Polyoxometalates Encapsulated in Silica Nanoparticles – Characterization and Photoluminescence Studies

AbstractThe incorporation of europium polyoxometalates into silica nanoparticles can lead to a biocompatible nanomaterial with luminescent properties suitable for applications in biosensors, biological probes, and imaging. Keggin‐type europium polyoxometalates Eu(PW11)x (x = 1 and 2) with different europium coordination environments were prepared by using simple methodologies and no expensive reactants. These luminescent compounds were then encapsulated into silica nanoparticles for the first time through the water‐in‐oil microemulsion methodology with a nonionic surfactant. The europium polyoxometalates and the nanoparticles were characterized by using several techniques [FTIR, FT‐Raman, 31P magic angle spinning (MAS) NMR, and TEM/energy‐dispersive X‐ray spectroscopy (TEM‐EDS), AFM, dynamic light scattering (DLS), and inductively coupled plasma MS (ICP‐MS) analysis]. The stability of the material and the integrity of the europium compounds incorporated were also examined. Furthermore, the photoluminescence properties of the Eu(PW11)x@SiO2 nanomaterials were evaluated and compared with those of the free europium polyoxometalates. The silica surface of the most stable nanoparticles was successfully functionalized with appropriate organosilanes to enable the covalent binding of oligonucleotides.

Decreased reticuloendothelial system clearance and increased blood half-life and immune cell labeling for nano- and micron-sized superparamagnetic iron-oxide particles upon pre-treatment with Intralipid

BackgroundSuperparamagnetic iron-oxide nanoparticles are useful as contrast agents for anatomical, functional and cellular MRI, drug delivery agents, and diagnostic biosensors. Nanoparticles are generally cleared by the reticuloendothelial system (RES), in particular taken up by Kupffer cells in the liver, limiting particle bioavailability and in-vivo applications. Strategies that decrease the RES clearance and prolong the circulation residence time of particles can improve the in-vivo targeting efficiency. MethodsIntralipid 20.0%, an FDA approved nutritional supplement, was intravenously administered in rats at the clinical dose (2g/kg) 1h before intravenous injection of ultra-small superparamagnetic iron-oxide (USPIO) or micron-sized paramagnetic iron-oxide (MPIO) particles. Blood half-life, monocyte labeling efficiency, and particle biodistribution were assessed by magnetic resonance relaxometry, flow cytometry, inductively-coupled plasma MS, and histology. ResultsPre-treatment with Intralipid resulted in a 3.1-fold increase in USPIO blood half-life and a 2-fold increase in USPIO-labeled monocytes. A 2.5-fold increase in MPIO blood half-life and a 5-fold increase in MPIO-labeled monocytes were observed following Intralipid pre-treatment, with a 3.2-fold increase in mean iron content up to 2.60pg Fe/monocyte. With Intralipid, there was a 49.2% and 45.1% reduction in liver uptake vs. untreated controls at 48h for USPIO and MPIO, respectively. ConclusionsIntralipid pre-treatment significantly decreases initial RES uptake and increases in-vivo circulation and blood monocyte labeling efficiency for nano- and micron-sized superparamagnetic iron-oxide particles. General significanceOur findings can have broad applications for imaging and drug delivery applications, increasing the bioavailability of nano- and micron-sized particles for target sites other than the liver.

The influence of the sample introduction system on signals of different tin compounds in inductively coupled plasma-based techniques

The influence of the sample introduction system on the signals obtained with different tin compounds in inductively coupled plasma (ICP) based techniques, i.e., ICP atomic emission spectrometry (ICP–AES) and ICP mass spectrometry (ICP–MS) has been studied. Signals for test solutions prepared from four different tin compounds (i.e., tin tetrachloride, monobutyltin, dibutyltin and di-tert-butyltin) in different solvents (methanol 0.8% (w/w), i-propanol 0.8% (w/w) and various acid matrices) have been measured by ICP–AES and ICP–MS. The results demonstrate a noticeable influence of the volatility of the tin compounds on their signals measured with both techniques. Thus, in agreement with the compound volatility, the highest signals are obtained for tin tetrachloride followed by di-tert-butyltin/monobutyltin and dibutyltin.The sample introduction system exerts an important effect on the amount of solution loading the plasma and, hence, on the relative signals afforded by the tin compounds in ICP–based techniques. Thus, when working with a pneumatic concentric nebulizer, the use of spray chambers affording high solvent transport efficiency to the plasma (such as cyclonic and single pass) or high spray chamber temperatures is recommended to minimize the influence of the tin chemical compound. Nevertheless, even when using the conventional pneumatic nebulizer coupled to the best spray chamber design (i.e., a single pass spray chamber), signals obtained for di-tert-butyltin/monobutyltin and dibutyltin are still around 10% and 30% lower than the corresponding signal for tin tetrachloride, respectively. When operating with a pneumatic microconcentric nebulizer coupled to a 50°C-thermostated cinnabar spray chamber, all studied organotin compounds provided similar emission signals although about 60% lower than those obtained for tin tetrachloride. The use of an ultrasonic nebulizer coupled to a desolvation device provides the largest differences in the emission signals, among all tested systems.

Different Analytical Methods of Para-Phenylenediamine Based Hair Dye

Many cases of toxicity and mortality either due to accidental or deliberate ingestion of hair dyes were reported in Egypt, Sudan, Israel, Morocco, Saudi Arabia, India and Tunisia. In the field of forensic analytical toxicology, the identification and quantification of chemicals are essential in deaths related to intoxication. The aim of the present study is to conduct chemico-analytical characterization of para-phenylenediamine (PPD) based hair dye of (Black stone hair dye, SHD) currently used for dying hear in Egypt, to confirm the identification of its components, that may be potentially toxic on oral or dermal exposure, this study uses comparison between different analytical methods. The applied analytical methods were inductively coupled plasma/MS (ICP/MS), witch used to determine the metal components of the dye, high performance liquid chromatography/MS (HPLC/MS) and gas chromatography/mass spectroscopy (GC/MS) were used for qualitative and quantitative analysis of PPD in the dye. A derivatization method was applied by transforming PPD (aromatic amines) into corresponding imine derivatives. This compound was prepared by condensation of 4-methylbenzeneamine with benzaldehyed to give N-benzylidene-4-methylbenzene-amine, which is a very stable internal standard. ICP/MS analysis revealed that most metal components of hair dye are Be, Na, Al, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Cu, and Zr, where HPLC/MS analysis revealed that PPD is the main ingredient of SHD. Derivatization is necessary for accurate determination of PPD in hair dye by GC/MS method and this results could not be obtained by direct injection of dye (without derivatization).

Elucidating the contribution of the elemental composition of fetal calf serum to antigenic expression of primary human umbilical-vein endothelial cells in vitro

One of the major obstacles to obtaining human cells of a defined and reproducible standard suitable for use as medical therapies is the necessity for FCS (fetal calf serum) media augmentation in routine cell culture applications. FCS has become the supplement of choice for cell culture research, as it contains an array of proteins, growth factors and essential ions necessary for cellular viability and proliferation in vitro. It is, however, a potential route for the introduction of zoonotic pathogens and makes defining the cell culture milieu impossible in terms of reproducibility, as the precise composition of each batch of serum not only changes but is in fact extremely variable. The present study determined the magnitude of donor variations in terms of elemental composition of FCS and the effect these variations had on the expression of a group of proteins associated with the antigenicity of primary human umbilical-vein endothelial cells, using a combination of ICPMS (inductively coupled plasma MS) and flow cytometry. Statistically significant differences were demonstrated for a set of trace elements in FCS, with correlations made to variations in antigenic expression during culture. The findings question in detail the suitability of FCS for the in vitro supplementation of cultures of primary human cells due to the lack of reproducibility and modulations in protein expression when cultured in conjunction with sera from xenogeneic donors.

Final report on CCQM-K70: Determination of Hg in natural water at a concentration level required by the European environmental quality standard (EQS)

This comparison 'Hg in natural water' was a follow-up to the pilot studies CCQM-P100.1 and CCQM-P100.2. The aim of this comparison was to demonstrate the capability of national metrology institutes to measure the Hg mass concentration in a natural water sample at the very low concentration level of γ(Hg) ≈ 70 ng/L as required by the EQS. In this way it served to help implement the European Water Framework Directive (WFD). This comparison was an activity of the Inorganic Analysis Working Group (IAWG) of CCQM and was piloted by Physikalisch-Technische Bundesanstalt (PTB, Braunschweig, Germany) with the help of the co-organizers Bundesanstalt für Materialforschung und -prüfung (BAM, Berlin, Germany), Laboratoire National de Métrologie et d'Essais (LNE, Paris, France), and the Joint Research Centre–Institute for Reference Materials and Measurements (EC–JRC–IRMM, Geel, Belgium).The following laboratories participated in this key comparison (in alphabetical order): BAM (Germany) EC–JRC–IRMM (European Union) KRISS (Republic of Korea) LGC (United Kingdom) LNE (France) NIST (United States of America) NMIA (Australia) NRC (Canada) PTB (Germany) SP (Sweden)The majority of participants applied isotope dilution mass spectrometry (IDMS) using sector field or quadrupole inductively coupled plasma MS (ICP-MS) in combination with cold vapour (CV) generation as the analytical technique. NRC reported a combined result of ID-CV-ICP-MS and CV atomic absorption spectrometry (CV-AAS). SP applied a standard addition method on a sector field ICP-MS, while BAM made use of an external 5-point calibration on a CV atomic fluorescence spectrometer (AFS). The key comparison reference value (KCRV) was agreed upon during the IAWG meeting in April 2010 at BIPM as the sum of the added Hg content calculated from the gravimetric sample preparation and the Hg matrix content of the water used for sample preparation (determined and validated on two independent pathways). Accordingly the degrees of equivalence were calculated.Main text.To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

Magnetic, Luminescent Eu‐Doped Mg–Al Layered Double Hydroxide and Its Intercalation for Ibuprofen

A magnetic, luminescent Eu-doped Mg-Al layered double hydroxide with ibuprofen (IBU) intercalated in the gallery has been successfully prepared by a simple coprecipitation method. The physicochemical properties of the samples were well characterized by powder XRD, TEM, FTIR, TGA, inductively coupled plasma MS (ICP-MS), vibrating sample magnetometry (VSM), and fluorospectrophotometry. The results revealed that Fe(3)O(4) nanoparticles are coated on the surface of layered double hydroxides and the obtained (Mg(2)Al(0.95)Eu(0.05))(Fe)-(IBU) sample exhibits both superparamagnetic and luminescent properties, with a saturation magnetization value of 1.86 emu g(-1) and a strong emission band at 610 nm, respectively. Additionally, it was found that the ibuprofen loading amount is about 31 % (w/w), and the intercalated ibuprofen possesses sustained release behavior when the magnetic, luminescent composite is immersed in simulated body fluid (SBF).

Comparison of Analytical Methods to Determine Sodium Content of Low-Sodium Foods

U.S. nutrition labeling regulations require the declaration of sodium content on food products. Accurate and reproducible determination of Na in foods with low Na content (< 140 mg/serving) is challenging because of laboratory contamination. Within-laboratory performance of inductively coupled plasma/MS (ICP/MS), flame atomic absorption spectrophotometry (FAAS), ion-selective electrode (ISE), and potentiometric titration of chloride ion were evaluated in 17 low-sodium foods. For 13 types of food, statistically significant differences (P < 0.05) exist between the within-day andlor interday means obtained by ICP/MS, FAAS, and ISE. Median within-day and interday precent RSD values were 2.7 and 6.1, 3.5 and 3.2, and 5.6 and 6.2%, respectively, by ICP/MS, FAAS, and ISE. The fewest matrix effects were found with ICP/MS, followed by FAAS, and ISE. FAAS gave higher results in a variety of matrixes when compared to ICP/MS and/or ISE. ISE did not perform well in fatty foods or at very low Na concentrations. Manufacturers' Nutrition Facts Panel sodium declarations exceeded levels found by analysis in > 70% of the foods. Analysis of chloride content does not produce reliable Na estimates in low-sodium foods, even when added sodium chloride is present. Methodological issues and contamination sources are discussed.