Inductively Coupled Plasma Optical Emission Spectroscopy Analysis Research Articles

Improving the osteogenic and angiogenic properties of synthetic hydroxyapatite by dual doping of bivalent cobalt and magnesium ion

The present study delineates improvement in the osteogenic and angiogenic properties of synthetic hydroxyapatite by dual doping of bivalent magnesium (Mg+2) and cobalt (Co+2) ions. The doped samples were prepared by ammoniacal precipitation method and characterized by Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES), X-Ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR) and Thermo Gravimetric Analysis (TGA). The study revealed that the extent of cobalt doping (ICP-OES analysis) was higher in comparison to magnesium. Doping of metal ions caused a slight distortion in the crystal structure (XRD analysis), increased apatite–water interaction (FT-IR) and decreased thermal stability (TGA analysis) of the hydroxyapatite. A preliminary evaluation showed that the doped samples had a significantly higher protein absorption capacity in comparison to pure hydroxyapatite. A detailed analysis pertaining to the bone cell (MG-63) compatibility and differentiation revealed that the doping significantly promoted cell proliferation and differentiation, as verified by Runt-related transcription factor 2 (Runx2) expression and in vitro nodule formation. When treated with doped samples, significant increase in intracellular hypoxia inducible factor 1 alpha (HIF-1α) expression was observed. That resulted in higher expression of vascular endothelial growth factor (VEGF), a key molecule that promotes angiogenesis. In conclusion, dual doping of magnesium and cobalt improves the osteogenic and angiogenic properties of hydroxyapatite and makes it a better biomaterial for bone tissue engineering.

The effect of mustard gas on salivary trace metals (Zn, Mn, Cu, Mg, Mo, Sr, Cd, Ca, Pb, Rb).

We have determined and compared trace metals concentration in saliva taken from chemical warfare injures who were under the exposure of mustard gas and healthy subjects by means of inductively coupled plasma optical emission spectroscopy (ICP-OES) for the first time. The influence of preliminary operations on the accuracy of ICP-OES analysis, blood contamination, the number of restored teeth in the mouth, salivary flow rate, and daily variations in trace metals concentration in saliva were also considered. Unstimulated saliva was collected at 10:00–11:00 a.m. from 45 subjects in three equal groups. The first group was composed of 15 healthy subjects (group 1); the second group consisted of 15 subjects who, upon chemical warfare injuries, did not use Salbutamol spray, which they would have normally used on a regular basis (group 2); and the third group contained the same number of patients as the second group, but they had taken their regular medicine (Salbutamol spray; group 3). Our results showed that the concentration of Cu in saliva was significantly increased in the chemical warfare injures compared to healthy subjects, as follows: healthy subjects 15.3± 5.45(p.p.b.), patients (group 2) 45.77±13.65, and patients (Salbutamol spray; group 3) 29 ±8.51 (P <0.02). In contrast, zinc was significantly decreased in the patients, as follows: healthy subjects 37 ± 9.03(p.p.b.), patients (group 2) 12.2 ± 3.56, and patients (Salbutamol spray; group 3) 20.6 ±10.01 (P < 0.01). It is important to note that direct dilution of saliva samples with ultrapure nitric acid showed the optimum ICP-OES outputs.

An Ultrasound-assisted Method on the Formation of Nanocrystalline Fluorohydroxyapatite Coatings on Titanium Scaffold by Dip Coating Process

In this study, titanium scaffolds with porosity of 60 volume percent were produced by Ti powder and urea space holder, using powder metallurgy technique. Dip-coating sol-gel process was used to coat titanium scaffolds with fluorohydroxyapatite (FHA) ceramics in order to improve their osteointegration for medical implant purposes. Scanning electron microscopy (SEM) with energy dispersive spectrometers (EDS), inductively coupled plasma optical emission spectroscopy (ICP-OES) and X-ray diffraction (XRD) were employed to ensure removal of urea particles, non-oxidized samples caused by sintering process as well as evaluation of nanocrystalline fluorohydroxyapatite coating structure. Results implied that ultrasonic irradiation could promote transferring of coating slurry into the pores and using a low temperature process improve crystallization and decreases the crystallite size of fluorohydroxyapatite to about 50nm. Moreover, ICP-OES analysis indicated that Ca:P molar ratio was 1.69, which was quite close to the molar ratios of the natural bone calcium and phosphor elements.

Solid-phase extraction of vanadium(V) from tea infusions and wines on immobilized nanometer titanium dioxide followed by ICP-OES analysis

Nanosized titanium dioxide immobilized on silica gel was synthesized and used as fixed-bed phase for V(V) pre-concentration, followed by inductively coupled plasma optical emission spectroscopy (ICP-OES) analysis. Three different sorbents were prepared by sol–gel method starting from a mixture of titanium isopropoxide, 2-propanol and water, and characterized by X-ray powder diffraction (XRPD), scanning electron microscopy (SEM) and BET analysis. V(V), the most stable and toxic oxidation state of the element, present in water and beverages samples, was selectively sorbed, pre-concentrated, quantitatively eluted by 0.1M HCl and analyzed by ICP-OES. The effectiveness of the procedure was first assessed on tap water enriched with 1μgL−1 of V(V) obtaining recoveries up to 92% (n=4). The pre-concentration step was then optimized for complex matrices such as tea infusions and red and white wines. The reliability of the procedure was assessed on the same beverages samples spiked with 20–250μgL−1. Quantitative recoveries (82–95%, n=4) were assured avoiding any sample pre-treatment, generally essential in such complex matrices, obtaining good precision (RSD<12%, n=3). The method was then applied to the determination of V(V) in commercial tea infusions and wines.

Rapid detection of transition metals in welding fumes using paper-based analytical devices.

Metals in particulate matter (PM) are considered a driving factor for many pathologies. Despite the hazards associated with particulate metals, personal exposures for at-risk workers are rarely assessed due to the cost and effort associated with monitoring. As a result, routine exposure assessments are performed for only a small fraction of the exposed workforce. The objective of this research was to evaluate a relatively new technology, microfluidic paper-based analytical devices (µPADs), for measuring the metals content in welding fumes. Fumes from three common welding techniques (shielded metal arc, metal inert gas, and tungsten inert gas welding) were sampled in two welding shops. Concentrations of acid-extractable Fe, Cu, Ni, and Cr were measured and independently verified using inductively coupled plasma-optical emission spectroscopy (ICP-OES). Results from the µPAD sensors agreed well with ICP-OES analysis; the two methods gave statistically similar results in >80% of the samples analyzed. Analytical costs for the µPAD technique were ~50 times lower than market-rate costs with ICP-OES. Further, the µPAD method was capable of providing same-day results (as opposed several weeks for ICP laboratory analysis). Results of this work suggest that µPAD sensors are a viable, yet inexpensive alternative to traditional analytic methods for transition metals in welding fume PM. These sensors have potential to enable substantially higher levels of hazard surveillance for a given resource cost, especially in resource-limited environments.

Effect of Gallium on Growth of Streptococcus mutans NCTC 10449 and Dental Tissues

Gallium-doped phosphate-based glasses (Ga-PBG) were assessed for their impact on Streptococcus mutans and dental mineralisation, firstly by disc diffusion assays followed by biofilms grown on nitrocellulose filter membrane (NFM) and constant-depth film fermentor (CDFF). Short-time exposure (10 min) effects of Ga-PBG on S. mutans biofilm were compared with that of 0.2% chlorhexidine. The effects of Ga-PBG on bovine enamel (which was investigated under pH-cycling condition) and dentine were analysed using transverse microradiography (TMR), profilometry and inductively coupled plasma optical-emission spectrometry (ICP-OES). The disc diffusion assays showed inhibition zones of 24.5 ± 0.5 mm for Ga-PBG compared with controls (C-PBG). Ga-PBG showed statistically significant growth inhibition of S. mutans biofilms on NFM (p = 0.001) and CDFF (p < 0.046) compared with hydroxyapatite (HA) and C-PBG. The CDFF assay revealed a maximum of 2.11 log colony-forming unit (CFU) reduction at 48 h, but short-time exposure effects were comparable with that of 0.2% chlorhexidine only on older biofilms (maximum of 0.59 vs. 0.69 log CFU reduction at 120 h). TMR analyses of the enamel revealed non-significant mineral loss (p = 0.37) only in the case of Ga-PBG samples compared with controls including sodium fluoride. ICP-OES analyses indicated transient gallium adsorption into dentine by calcium displacement. The results confirmed that gallium inhibited S. mutans growth and appears to have the potential to protect the enamel surface under conditions representative of the oral environment. Further work is needed to establish whether it has an application in daily oral hygiene procedures to prevent or reduce caries.

Investigations on synthesis, growth, electrical and defect studies of lithium selenoindate single crystals

LiInSe2 polycrystalline material was successfully synthesized from melt and temperature oscillation method (MTOM). The crystalline phase was confirmed by powder X-ray diffraction pattern. Crack free LiInSe2 single crystal of size 12mm diameter and 32mm length was grown using two zone tubular resistive heated furnace by modified vertical Bridgman–Stockbarger method with steady ampoule rotation. The grown LiInSe2 crystal was subjected to single crystal XRD, inductively coupled plasma-optical emission spectroscopy (ICP-OES), positron annihilation spectroscopy (PAS), Hall effect and dielectric measurements. Single crystal XRD measurement confirms the orthorhombic crystal system. ICP-OES analysis gives the crystal composition as Li0.81In1.01Se2.18. The average lifetime 278.03ps in PAS measurements corresponds to vacancy clusters present in LiInSe2 crystal. Hall effect measurement confirms the n-type semiconductor nature. The dielectric permittivity and dielectric loss were obtained to be 9.8 and 0.108 respectively by capacitance measurements at room temperature for the frequency of 2MHz.

The Early Bronze Age settlement of Fidvár, Vráble (Slovakia): reconstructing prehistoric settlement patterns using portable XRF

This paper presents first results of chemical analyses of sediment samples from the Early Bronze Age (EBA) settlement Fidvár near Vráble (Slovakia). Large-scale geomagnetic prospection revealed detailed architectural remains of a fortified settlement. Other structures such as an earthwork of the linear pottery culture and at least two Roman march camps were found too. An Auger programme provided sediment samples of different depths, A) from an EBA house and the outer fortification ditch, B) from a potential metal workshop area as indicated by surface finds, and C) from an area located in the settlement's centre. The samples were analysed by a portable X-ray fluorescence (pXRF) spectrometer in order to investigate the vertical and horizontal distribution of chemical signatures. The comparison of geophysical data and three-dimensional chemical patterns gives us the opportunity to determine the human impact and to reconstruct activity patterns. The potentials and limits in the application of pXRF in archaeological soil chemical surveys are evaluated by systematic comparisons with high resolution laboratory measurements, including atomic absorption spectrometry (AAS) and inductively coupled plasma optical emission spectrometry (ICP-OES). The pXRF analyses can be reproduced well and show a good accuracy. Whilst (p)XRF analyses reflect the total composition of archaeological soil samples, the results of the AAS and ICP-OES analyses are fundamentally influenced by the acid digestion or extraction methods used. The pXRF analyses of the Vráble soils showed typical patterns of human occupation. For example, there are strong positive correlations between phosphorous, strontium and calcium. Phosphorous shows an enrichment in pathways and the fortification ditch. It is less strongly enriched within the sediments of house structures. Similar results apply to calcium and strontium distribution. But compared to the respective concentrations in sediment samples from the ditch they show a considerably higher variation in samples associated with house structures; that is, individual samples of sediments from house structures contained high concentrations of both, calcium and strontium. The deposits of an area that according to surface finds was thought to represent a potential metal workshop did not show indicative chemical signatures. Targeted excavations confirmed the absence of such as workshop. Finally it was shown that the refill history of the innermost fortification ditch (sample area D) and the overall cultural occupation sequence at the site correlate strongly with the chemical signatures of the respective ditch profile. The systematic variation of key elements along the profile opens up an entirely new perspective for interpreting the site's history. Overall, the study shows the great potential of pXRF as valuable part of an archaeological survey toolkit.

A novel approach for the direct determination of residual template molecules in molecularly imprinted polymer matrices

With inductively coupled plasma optical emission spectroscopy (ICP-OES), this article introduces an analysis method enabling the direct quantitative determination of residual template molecules in molecularly imprinted polymer (MIP) matrices. ICP-OES was applied for the determination of residual iodine in MIPs prepared against the iodinated X-ray contrast agent iohexol. Prior to analysis, a microwave-assisted acidic oxidative digestion method was developed simultaneously enabling the digestion of the polymer matrix and the exhaustive oxidation of organically bound iodine. Excellent recovery rates and a high accuracy confirm the feasibility and utility of a microwave-assisted digestion with subsequent ICP-OES analysis for the determination of residual iodine in MIPs, and indicate the potential of this combination as a widely applicable monitoring tool for the efficiency of template extraction from MIP matrices.

Nondestructive analysis of single crystals of selenide spinels by X-ray spectrometry techniques

The paper presents possibilities and difficulties in nondestructive analysis of small multielement single crystals performed by means of X-ray spectrometry techniques: micro-X-ray fluorescence spectrometry (μ-XRF), energy-dispersive electron probe microanalysis (ED-EPMA), and X-ray photoelectron spectroscopy (XPS). The capability of the X-ray spectroscopy techniques in elemental analysis is demonstrated with the single crystals of selenide spinels of the general formula MxNyCrzSe4 (M+2 and N+3 are, for example, Zn+2, V+3, Ga+3, Cd+2, In+3, and Sb+3). The results of the nondestructive analyses (μ-XRF, ED-EPMA, and XPS) are compared with those obtained by inductively coupled plasma optical emission spectrometry (ICP-OES) and wavelength-dispersive X-ray spectrometry (WDXRF) following sample digestion. The present study shows satisfactory agreement between the results of μ-XRF analysis performed using the standardless fundamental parameter method and the results obtained with the WDXRF and ICP-OES analyses. If the measured single crystal is precisely positioned, the difference between μ-XRF and wet analysis (WDXRF and ICP-OES) does not exceed 5% rel. The reliable results of ED-EPMA can be obtained only if the measured area is sufficiently large, i.e., of 200 × 300 μm. Even if this condition is fulfilled, the relative difference between the ED-EPMA and the wet analysis may reach 10% rel. In case of the XPS analysis, the accuracy of results depends on the proper preparation of the sample surface. It should be free of contamination that can be obtained by scraping in situ in ultrahigh vacuum. The ion etching, commonly used for cleaning the surface, leads to preferential sputtering; therefore, the reliable results cannot be obtained. FigureThe paper presents possibilities and difficulties in nondestructive analysis of small multielement single crystals performed by means of X-ray spectrometry techniques: micro-XRF, ED-EPMA and XPS.

Stoichiometry determination of (Pb,La)(Zr,Ti)O3-type nano-crystalline ferroelectric ceramics by wavelength-dispersive X-ray fluorescence spectrometry

Analysis of small samples of lanthanum-doped lead zirconate titanate (PLZT) by wavelength-dispersive X-ray fluorescence spectrometry (WDXRF) is presented. The powdered material in ca. 30 mg was suspended in water and collected on the membrane filter. The pure oxide standards (PbO, La2O3, ZrO2 and TiO2) were used for calibration. The matrix effects were corrected using a theoretical influence coefficients algorithm for intermediate-thickness specimens. The results from XRF method were compared with the results from the inductively coupled plasma optical emission spectrometry (ICP-OES). Agreement between XRF and ICP-OES analysis was satisfactory and indicates the usefulness of XRF method for stoichiometry determination of PLZT.

A comparison of portable XRF and ICP-OES analysis for lead on air filter samples from a lead ore concentrator mill and a lead-acid battery recycler

Personal and area samples for airborne lead were taken at a lead mine concentrator mill, and at a lead-acid battery recycler. Lead is mined as its sulfidic ore, galena, which is often associated with zinc and silver. The ore typically is concentrated, and partially separated, on site by crushing and differential froth flotation of the ore minerals before being sent to a primary smelter. Besides lead, zinc and iron are also present in the airborne dusts, together with insignificant levels of copper and silver, and, in one area, manganese. The disposal of used lead-acid batteries presents environmental issues, and is also a waste of recoverable materials. Recycling operations allow for the recovery of lead, which can then be sold back to battery manufacturers to form a closed loop. At the recycling facility lead is the chief airborne metal, together with minor antimony and tin, but several other metals are generally present in much smaller quantities, including copper, chromium, manganese and cadmium. Samplers used in these studies included the closed-face 37 mm filter cassette (the current US standard method for lead sampling), the 37 mm GSP or "cone" sampler, the 25 mm Institute of Occupational Medicine (IOM) inhalable sampler, the 25 mm Button sampler, and the open-face 25 mm cassette. Mixed cellulose-ester filters were used in all samplers. The filters were analyzed after sampling for their content of the various metals, particularly lead, that could be analyzed by the specific portable X-ray fluorescence (XRF) analyzer under study, and then were extracted with acid and analyzed by inductively coupled plasma optical emission spectroscopy (ICP-OES). The 25 mm filters were analyzed using a single XRF reading, while three readings on different parts of the filter were taken from the 37 mm filters. For lead at the mine concentrate mill, all five samplers gave good correlations (r2 > 0.96) between the two analytical methods over the entire range of found lead mass, which encompassed the permissible exposure limit of 150 mg m(-3) enforced in the USA by the Mine Safety and Health Administration (MSHA). Linear regression on the results from most samplers gave almost 1 ratio 1 correlations without additional correction, indicating an absence of matrix effects from the presence of iron and zinc in the samples. An approximately 10% negative bias was found for the slope of the Button sampler regression, in line with other studies, but it did not significantly affect the accuracy as all XRF results from this sampler were within 20% of the corresponding ICP values. As in previous studies, the best results were obtained with the GSP sampler using the average of three readings, with all XRF results within 20% of the corresponding ICP values and a slope close to 1 (0.99). Greater than 95% of XRF results were within 20% of the corresponding ICP values for the closed-face 37 mm cassette using the OSHA algorithm, and the IOM sampler using a sample area of 3.46 cm2. As in previous studies, considerable material was found on the interior walls of all samplers that possess an internal surface for deposition, at approximately the same proportion for all samplers. At the lead-acid battery recycler all five samplers in their optimal configurations gave good correlations (r2 > 0.92) between the two analytical methods over the entire range of found lead mass, which included the permissible exposure limit enforced in the USA by the Occupational Safety and Health Administration (OSHA). Linear regression on the results from most samplers gave almost 1 ratio 1 correlations (except for the Button sampler), indicating an absence of matrix effects from the presence of the smaller quantities of the other metals in the samples. A negative bias was found for the slope of the button sampler regression, in line with other studies. Even though very high concentrations of lead were encountered (up to almost 6 mg m(-3)) no saturation of the detector was observed. Most samplers performed well, with >90% of XRF results within +/- 25% of the corresponding ICP results for the optimum configurations. The OSHA algorithm for the CFC worked best without including the back-up pad with the filter.

Total suspended dust and heavy metal levels emitted from a workplace compared with nearby residential houses

Total suspended particulate matter (TSP) were collected from the workplace in Sohar Industrial Estate (SIE) in Oman. The samples were taken from 19 different industrial activities that represent major sources of particulate matter in the SIE. The collected samples were analyzed for 9 heavy metals (Cr, Cu, Mn, Ni, Pb, Zn, Cd, V and Mo) by using the inductively coupled plasma optical emission spectrometry analysis (ICP-OES). Furthermore, the indoor TSP and heavy metal concentrations were measured inside 12 houses within Sohar residential area to determine the contributions of various industrial activities on nearby residential houses. The results indicated that the mean concentrations of heavy metals in the TSP were too low to yield any known environmental health effects. In general, the results showed that the concentrations of heavy metals in the workplaces of SIE and its nearby houses were low compared to the guideline values. In addition, the values were low in comparison with other known sites around the world. Moreover, significant contribution from industrial sources at SIE was evidenced at nearby houses.

Improved ICP-OES analysis of trace calcium in rare-earth matrices with the use of iterative target transformation factor analysis and Kalman filter

When trace elements present in complex matrices are analysed by inductively coupled plasma optical emission spectroscopy (ICP-OES) correction must be made for the background if it overlaps with the desired trace analyte spectrum. However, often this is difficult to achieve because the required pure materials for the complex background matrix cannot be obtained, and hence the standard spectra are unavailable. A chemometrics solution to resolve the overlapping ICP-OES spectra of some such systems (gray systems) is proposed in this paper so as to obviate the need for the background standards. The case considered involves trace calcium in the presence of a large rare-earths background: Pr–Ca, Nd–Ca, Tb–Ca, Ho–Ca and Er–Ca. The application of iterative target transformation factor analysis (ITTFA) is explored to resolve the spectral interferences produced by the ultra-high-purity rare-earth matrices so as to facilitate the determination of the trace calcium. Once the ITTFA method has extracted the required background spectrum, a Kalman filter (KF) procedure is then used for the quantitative determination of the trace element. The calcium results are compared with those estimated by the conventional standard addition method, and improved results are observed. In addition, while in the absence of suitable standards such an approach is essential for the problem of the determination of the trace calcium in the rare-earth matrix described, this method should also be applicable to white systems, thereby often reducing costs of analysis as well as labour associated with the preparation of background material standards.

Measuring heavy metals by quantitative thermal vaporization

It is our vision to separate volatile toxic contaminants from waste by thermal treatment. In this context the evaporation behavior of heavy metal traces (Cd, Cu, Pb, and Zn) from model compounds and mixtures, and from fly ash (FA) of municipal solid waste incineration (BCR No. 176) was investigated. In this study we tested a new method which allows on-line detection of heavy metals in hot gases using conventional Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) equipment. A quantitative relation between the amount of evaporated heavy metal traces and the ICP-OES signal was established. In addition, gaseous HCl was successfully used for the total removal of heavy metal traces from non-volatile compounds. The evaporation behavior predicted by speciation calculations were in agreement with the experimental results. The experiments have shown that the method could become a complementary tool for common analytical digestion and measuring methods for the determination of heavy metal traces in solid samples. As our method combines extraction and analytical steps it therefore can shorten conventional procedures. It allows simultaneous, and compared to a conventional digestion and ICP-OES analysis, more sensitive measurements of several elements. The application could become especially powerful for the analysis of contaminated soil and waste residuals.