Search

This work demonstrates the effect of NaCl and carbon-related interferences on the analysis of arsenic and silver nanoparticles (NPs) by single-particle inductively coupled plasma mass spectrometry. Spectral interference caused by ArCl+ ions disturbing arsenic NPs analysis was eliminated using ammonia as reaction gas in a dynamic reaction cell of inductively coupled plasma mass spectrometer. In comparison to aqueous dispersions, non-spectral interferences caused by sodium lead to under-evaluation of arsenic and silver NPs diameter by about 7% and 15% at NaCl concentration of 450 mg L−1 and about 28% and 41% at NaCl concentration of 4500 mg L−1, respectively. As a consequence of lower transport efficiency, sodium non-spectral interferences also lead to about a 9% lower number of detected NPs for dispersions of both arsenic and silver NPs in 4500 mg L−1 NaCl. On the contrary, measurement of NPs in matrices containing methanol gives results where Ag and As NPs diameter is over-evaluated by about 3% and 15% at a methanol content of 1% (v/v) and about 6% and 20% at a methanol content of 2% (v/v), respectively, in comparison to aqueous dispersions. In addition, the organic carbon species behave as surfactants and increase the transport efficiency; this leads to an increase in the determined number concentration of NPs. In comparison to aqueous dispersions, this is over-evaluated by about 17% for Ag NPs and about 10% for As NPs at a methanol content of 5% (v/v).

Using silver sulfide quantum dots (Ag2S) and graphitic carbon nitride nanosheets (g-C3N4), an effective and facile ratiometric fluorescence sensor for the selective determination of Cerium was developed. The addition of cerium to this probe solution resulted in the fluorescence at 443 nm quenching, while the fluorescence of the Ag2S QDs at 540 nm recovering. The linear response range of this ratiometric sensor for Cerium was from 0.5 × 10 −6 mol L−1 to 3.2 × 10 −5 mol L−1. In this sensing system, not only was the detection limit as low 6.4 × 10 −8 mol L−1, which was as good or better than similar assays, but the sensing system also demonstrated good selectivity in detecting cerium in the presence of interfering substances. The possible mechanism is discussed. Furthermore, this ratiometric fluorescence probe was successfully employed for the detection of Cerium in real samples with satisfactory results. The results were compared with those obtained using inductively coupled plasma optical emission spectrometry (ICP-OES).

Multi-elemental speciation analysis in a single run reduces costs, waste and time, and also sample consumption, which is favorable to a large set of instable samples. This work demonstrates mercury and arsenic speciation in a single run using high performance liquid chromatography with inductively coupled plasma mass spectrometric detection (HPLC/ICP-MS). Thiol compounds in mobile phases interfered with the elution of arsenite because of coordination action, which was overcome by gradient elution (elution of As(III) by thiol-free mobile phases at first). Four arsenic forms (As(III), DMA, MMA and As(V)) and three mercury species (Hg(II), MeHg and EtHg) were separated and detected by HPLC/ICP-MS using 4 mM tetrabutylammonium hydroxide (TBAH) (pH 6.0) in the first 1.0 min and 4 mM TBAH + 20 mM L -cysteine (pH 6.0) in the next 9.0 min. The detection limits were obtained at 0.078 for As(III), 0.081 for DMA, 0.078 for MMA and 0.15 μg L−1 for As(V), and 0.016 for Hg(II), 0.027 for MeHg and 0.032 μg L−1 for EtHg, and the reproducibilities (50 μg L−1 for each As-species and 10 μg L−1 for each Hg-species) were all lower than 3.7%. The proposed method was successfully applied for speciation analyses of arsenic and mercury in five lotus roots, which indicated DMA (3.5–7.9 μg kg−1) as the only arsenic species and MeHg (0.6–1.0 μg kg−1) as the only mercury species. Analyses of two certified reference materials demonstrated good agreement between determined values and certified values. All results prove its advantages including high sensitivity and high analytical efficiency, which are beneficial for routine speciation analyses of arsenic and mercury in a single run in environmental and food fields.

An alternative method for the determination of total chlorine content in hydroxypropyl cellulose (HPC) was applied, combining a recently developed system based on a combustion step followed by pyrohydrolysis reaction. Using this approach it the determination of total chlorine by inductively coupled plasma optical emission spectrometry (ICP-OES) without interferences was feasible. It overcame the limitations of European Pharmacopoeia (EP) method for HPC analysis regarding to the inability to determine total chlorine in HPC, once some chlorine compounds (e.g., chloroform) that can not be identified by the official method (EP). The following parameters of combustion and pyrohydrolysis were evaluated: absorbing solution, sample mass, the use of powdered silica as retardant of combustion, oxygen flow rate and reaction time. Reference values for total chlorine were obtained after digestion using microwave-induced combustion and determination by ion chromatography (IC). Microwave-assisted extraction (MAE) was also investigated for Cl extraction. The accuracy of the proposed method was also evaluated by analyte recovery tests (agreement of 95–103%), as well as by the analysis of certified reference materials (CRMs). The agreement with the certified values was higher than 95% and the limit of quantification (LOQ) was 50 µg g−1. Up to 500 mg of sample were efficiently digested by the proposed method in 5 min (dissolved carbon in digests was below 50 mg L−1). Total chlorine content in samples of modified cellulose ranged from 284 to 576 µg g−1. Despite the relatively high chlorine content in all samples, the concentration was lower than the maximum limit allowed by the EP for HPC (0.5%).

Size exclusion chromatography (SEC) hyphenated to inductively coupled plasma – mass spectrometry (ICP-MS), as a specific detector for metals, has been used for monitoring and determining metal-low molecular weight organic compound (LMWC) complexes in natural wines. SEC with UV detection (wavelength of 205 nm) was used for monitoring organic compounds eluted from the chromatographic column. SEC-UV has revealed the presence of low molecular weight compounds (commonly three fractions of molecular weights ranging from 230 to 1579 Da).’ Further experiments using ICP-MS as a detector showed that elements such as B, Cu, Li, Mn, Ni, Ti, and Zn are bound to compounds of molecular weights within the 338–1579 Da range. Total metal concentrations, as well as metal concentrations in SEC fractions were also assessed in several monovarietal red (five varieties) and monovarietal white (three varieties) wines.

The accurate measurement of heavy metal ions is essential for human health and environmental protection. Here, we report the design of a simple and convenient bimodal strategy for signal-on, label-free lead ion detection in environmental samples based on two-dimensional metal–organic framework (2D-MOF) nanosheets. 2D-MOFs have different affinities toward guanine-rich DNA (ssGDNA) and the G-quadruplex, allowing these structures to be distinguished. The nanosheets were also used as quenchers for fluorescent lead ion detection. Using lead ions to induce G-quadruplex formation from ssGDNA, a simple fluorescence resonance energy transfer (FRET) strategy was developed for lead ion detection; the detection limit was 3.3 nM. Based on changes in the GDNA configuration, the FRET system was converted into an electrochemical sensor for lead ion assays using an electrode modified with the 2D-MOF nanosheets. Electrochemical impedance spectroscopy showed a high sensitivity and a low limit of detection (i.e., 8.7 pM) of the electrode. The adaptability of the bimodal mechanism was verified through the successful detection of lead ions in tap water and fertilizer samples, and the method accuracy was demonstrated through inductively coupled plasma analysis. The developed bimodal device is cost-effective, highly sensitive, and allows for convenient operation, thereby rendering it a promising and reliable system for the detection of lead ions in environmental samples.

The characterisation of individual nanoparticles by single particle ICP-MS (SP-ICP-MS) has paved the way for the analysis of smallest biological systems. This study suggests to adapting this method for single viruses (SV) identification and counting. With high resolution multi-channel sector field (MC SF) ICP-MS records in SV detection mode, the counting of master and key ions can allow analysis and identification of single viruses. The counting of 2–500 virial units can be performed in 20 s. Analyses are proposed to be carried out in Ar torch for master ions: 12C+, 13C+, 14N+, 15N+, and key ions 31P+, 32S+, 33S+ and 34S+. All interferences are discussed in detail. The use of high resolution SF ICP-MS is recommended while options with anaerobic/aerobic atmospheres are explored to upgrade the analysis when using quadrupole ICP-MS. Application for two virus types (SARS-COV2 and bacteriophage T5) is investigated using time scan and fixed mass analysis for the selected virus ions allowing characterisation of the species using the N/C, P/C and S/C molar ratio's and quantification of their number concentration.

Inductively coupled plasma tandem mass spectrometry (ICP-MS/MS) was investigated for possible use in food fraud studies through the measurement of strontium and sulfur isotope ratios. Oxygen mass shift mode was applied to shift 87Sr/86Sr and 34S/32S isotope ratios to their respective oxides, 87Sr16O+/86Sr16O+ and 34S16O+/32S16O+, effecting a gas-phase chemical separation of the elements from Rb and Kr (for Sr) and molecular N and O species, along with P- and S-hydrides (for S). A total least squares regression approach was employed to generate the isotope ratio data from time-resolved analyses, and method uncertainties and accuracies were determined. The utility of the approach was shown by using the Sr and S isotope ratios together to differentiate between NIST RM 8256 Wild-Caught Coho Salmon and NIST RM 8257 Aquacultured Coho Salmon. These materials are currently under development at NIST as certified food fraud standards and method evaluation materials for comprehensive chemical analysis.

As a natural adsorbent, sisal (agave sisalana) fibers were used to extract Cu, Ni, Mn, and Zn from diesel oil samples for posterior determination (i.e., direct analytical measurements on the solid support) of the analytes by energy dispersive X-ray fluorescence spectrometry (EDXRF). In the proposed procedure, 0.2 g of sisal fiber was directly added to 5.0 mL of diesel oil contained in a glass tube. After 5 min of contact time, the mixture was filtered, and the collected fibers were oven-dried for 30 min at 70 °C. After drying, the analytes were quantified directly by EDXRF using the sisal fibers as a solid support. The calibration curves showed linear concentration ranges of 0.09–1.00, 0.12–1.00, 0.09–1.00, 0.06–1.0 μg g−1 for Cu, Ni, Mn, and Zn, respectively. The limits of detection (LOD) for Cu, Ni, Mn, and Zn were 0.03, 0.04, 0.03, and 0.02 μg g−1, respectively. The repeatability, evaluated by performing ten measurements at a concentration of 0.50 μg g−1 for each metal, with the results expressed in terms of the relative standard deviation (RSD), was 3.2, 6.5, 6.8, and 6.1% for Cu, Ni, Mn, and Zn, respectively. The results obtained by the proposed method were compared with the results obtained by a comparative method using inductively coupled plasma optical emission spectrometry, and both results showed good agreement. The proposed method was applied for Ni, Cu, Mn, and Zn determination in diesel oil samples collected from different gas stations.

A simple analytical procedure has been developed for the determination of trace rare earth elements (REEs) in uranium materials by inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma optical emission spectrometry (ICP-OES), after selective extraction of uranium matrix using tri(2-ethylhexyl)phosphate (TEHP). The separation method reduces uranium concentration in the raffinate to less than 10 mg L−1 (from initial value of ~40,000 mg L−1), thus, eliminating severe matrix interferences from uranium, such as isobaric and polyatomic interferences in ICP-MS, and spectral interferences in ICP-OES. The raffinate is directly used for the analysis of REEs, without any pretreatment. The proposed method was validated by applying it to the ICP-MS determination of REEs in uranium dioxide (UO2) samples, by spiking with standard reference REE solutions and performing the recovery tests. The recoveries ranged from 94.0 to 105.5%. The validation was also performed similarly for ICP-OES measurements on U3O8 as well as UO2 samples, which provided recoveries in the ranges of 96–105.8% and 99.2–101.6%, respectively. The method offers a fast, simple and effective method with low detection limit, and is suggested for the determination of REEs in uranium-based nuclear grade materials such as uranyl nitrate hexahydrate, uranium hexafluoride and uranium trioxide.

The analysis of impurities in a uranium ore concentrate (UOC) could provide information regarding the source, production history, and potential intended use of the UOC. This study involves the analysis of UOC samples for phosphorus and sulfur. Concentrations were determined by triple quadrupole inductively coupled plasma – mass spectrometry and compared with results from a pyrohydrolysis method as well as previously reported results. The sulfur and phosphorus concentrations, determined by the mass spectrometer, were used to explore possible trends in a series of UOC material, and the uncertainties were calculated using GUM workbench software. The triple quadrupole inductively coupled plasma – mass spectrometer method allows for the removal of interferences in the analysis of species.

A method was developed based on reversed-phase vortex-assisted liquid-liquid microextraction (RP-VALLME) combined with energy dispersive X-ray fluorescence (EDXRF) spectrometry for the determination of Cu, Mn, Ni, and Pb in diesel oil samples. In this procedure, a nitric acid solution was used as the extraction phase to isolate analytes from organic samples. After a centrifugation step, the aqueous phase was added dropwise to a filter paper disc for EDXRF determinations. The following variables were optimized: type of extraction phase solution, concentration of the extraction phase, stirring time, and sample volume. Some instrumental parameters were also evaluated: atmospheric condition, irradiation energy, and irradiation time. Using 100 μL of a 0.075 mol L−1 nitric acid solution as the extraction phase for a sample volume of 5.0 mL and a stirring time of 45 s, the limits of detection were 14, 8, 10, and 7 μg L−1 for Cu, Mn, Ni, and Pb, respectively. The enrichment factors obtained were 34 (Cu), 62 (Mn), 59 (Ni), and 64 (Pb). The precisions, expressed as relative standard deviations (RSDs, %), were calculated from ten replications of the experiment under optimized conditions using standard solutions containing 200 μg L−1 and 400 μg L−1 of all four analytes and ranged between 2.1 and 6.4%. The results of recovery tests ranged from 87 to 112%. The proposed procedure was efficiently applied to the determination of the four analytes in diesel oil samples. The results were compared with those obtained by inductively coupled plasma optical emission spectrometry (ICP-OES) after sample digestion, and no significant differences were found.

A new procedure is proposed for the determination of metal contaminants (Cr, Fe, Mg, Mn, Na and Ni) in polymeric diphenylmethane diisocyanate (PMDI), a raw material used to produce polyurethane polymers. The feasibility of using Zeeman-effect background correction graphite furnace atomic absorption spectrometry (GF AAS) and direct sampling (DS) was evaluated. Calibration using aqueous standard solutions was feasible and chemical modifiers as well as reference materials for this purpose were unnecessary. Relatively high sample masses (up to 23 mg) were used allowing very low limits of detection ranging from 0.06 ng g-1 to 1 ng g-1 (Fe and Mg) up to 3 ng g-1 (Ni), with relative standard deviation lower than 15%. The following parameters were evaluated: pyrolysis and atomization temperatures , sample mass, as well as the use of low sensitivity conditions (Zeeman effect background correction magnetic field strength adjustment and the use of a secondary wavelength for Fe and Na determinations, respectively). Results were compared with those obtained by microwave-assisted digestion and microwave-induced combustion with subsequent analytes determination by inductively coupled plasma optical emission spectrometry (ICP-OES) and by inductively coupled plasma mass spectrometry (ICP-MS). No significant difference was observed between the results obtained by DS-GF AAS, ICP-MS and ICP-OES after both digestion systems. The proposed DS-GF AAS method allowed the determination of six elements in PMDI (which is considered as a complex matrix) with limits of detection lower than those achieved by other methods. This new procedure can be used as quality control of polyurethanes industry for ultra-trace inorganic impurities.

In this work, we applied laser-induced breakdown spectroscopy (LIBS) to estimate the amount of toxic heavy metals (Pb, Cr, Ni) in five different brands of face foundation powders available in the local market using standard calibration curve (CC)-LIBS approach. These samples contain toxic elements like lead, chromium, nickel which are highly carcinogens to cause eczematous and atopic dermatitis. The strongest atomic transition lines of lead (405.7 line), chromium (425.4 nm line), and nickel (336.9 nm line) were used as spectral markers to simultaneously detect these three heavy metals in face powder samples. The LIBS experimental parameters (delay time, laser energy, and focusing lens to target spacing) were optimized to enhance the signal to noise ratio in the resulting LIBS spectra. The consequence of self-absorption on the marker peaks used in the LIBS analysis was investigated and found to be insignificant. We calibrated our LIBS system for these three heavy metals, whose levels were found above the permissible limits. The face foundation powder used every day augments up to considerable exposure of heavy metals in the human body which could cause many skin disorders. Our LIBS quantitative results were also cross-validated by analysis using a standard analytical technique known as inductively coupled plasma-optical emission spectroscopy (ICP-OES). This study is highly significant due to the excessive use of cosmetic products especially face powder that could affect the health of millions of people around the globe.

A novel and sensitive method for the selective determination of Cr(VI) and non-chromatographic speciation of Cr(VI) and Cr(III) was developed based on chemical vapor generation (CVG) in KBH4-acid system for sample introduction into an inductively coupled plasma mass spectrometer (ICP-MS) for detection. The CVG of Cr(VI), rather than Cr(III), was found to be remarkably enhanced in the presence of sodium diethylaminodithioformate (DDTC). After the oxidation of Cr(III) to Cr(VI) by KMnO4, the quantitation of Cr(III) could be obtained based on the difference between the concentration of total chromium and that of Cr(VI). Parameters affecting the CVG reaction and determination of Cr(VI) were evaluated in detail, including the concentrations of DDTC, hydrochloric acid and KBH4, the sample flow rate, as well as the length of reaction and transferring tubing. Under optimal conditions, the CVG efficiency and the limit of detection (LOD) of Cr(VI) were found to be 28% and 0.2 ng mL−1, respectively. The relative standard deviations for seven replicate measurements of 20 ng mL−1 of Cr(Ⅵ) was 1.8%. Furthermore, with excess DDTC (100 μg mL−1) added to the test solutions, possible interferences from Cu2+ (up to 400 ng mL−1) could be eliminated. The proposed method was thus successfully applied to the determination of Cr(VI) in three real water samples and one certified reference water sample, as well as two simulated water samples of Cr(VI) and Cr(III), all with satisfactory results. The possible reasons were discussed for the varied degrees of enhancement between Cr(III) and Cr(VI).

In this study, a first attempt for isolating and determining (characterising) background levels of titanium dioxide nanoparticles (TiO2 NPs) in seaweed has been developed by using single particle inductively coupled plasma – mass spectrometry (SP-ICP-MS). Seaweeds were processed using an optimised ultrasound assisted extraction (UAE) procedure based on tetramethylammonium hydroxide (TMAH) before dilution and SP-ICP-MS analysis. The effect of the TMAH percentage in the extracting solution, as well as the volume of extracting solution and sonication (extraction) time, has been fully assessed. Additional experiments also showed that TiO2 NPs were quantitatively released from the seaweed matrix in one UAE step since the analysis of residues gave TiO2 NPs concentrations lower than the limit of quantification (LOQ) of the method. Validation of the method with 50 and 100 nm TiO2 NPs (10 μg L−1 as Ti) showed good analytical recovery (115% and 112% for 50 and 100 nm TiO2 NPs, respectively), and good reproducibility (2% for size and 16% for number of TiO2 NPs). Experiments regarding TiO2 NPs stability showed that the extracted NPs are stable since there were not changes on the number of TiO2 NPs and TiO2 NPs size distributions when exposing TiO2 NPs standards to the optimised extractive conditions.

Soluble aluminium (Al(sl)) in high silicon alloys is determined by electrolytic dissolution flow injection analysis (ED-FIA) and inductive coupled plasma with optical emission spectrometry (ICP-OES). Skipping the time consuming sample preparation known from acid hydrolysis reduces the required time per determination from 15 to 4 min. A new calculation procedure is used to compensate the discrepancy in matters of dissolution between acid hydrolysis and electrolytic dissolution. Samples with a known silicon content (2,5 and 3,1 wt%) are used to determine the differences of dissolved material and to calculate a correction factor. In a working range of 200–350 ppm aluminium in high silicon steel, there is a standard deviation of 7 ppm for a measurement series of 19 samples (max deviation 19 ppm).

In this study, inductively coupled plasma optical emission spectrometry (ICP OES) was used for the development of an analytical procedure for elemental analysis of hard disks (HDs). More than 50 samples were acquired and separated according to the manufacturers. Both magnets were used, namely, the actuator (a) and the spindle (s) motor. The samples were heated to remove magnetism, ground in a knife mill and sieved. Different digestion procedures were performed with a block digester and microwave, and three acid concentrations were employed. Due to the lack of certified materials or references from HDs, tests of standard addition and recovery were performed to verify the accuracy of the proposed method. Hyperspectral image and principal component analysis were also used to assist in the data treatment related to the Ni layer. For both magnets, the best analytical procedure was 100 mg of sample, 7 mol L−1 nitric acid and a digester block. The elements observed in the highest concentrations were Fe followed by Nd and Pr. This procedure was simpler than others were and prioritized the principles of green chemistry.

A novel approach for serum analysis by dried matrix spot (DMS) technique is proposed. The methodology consists of sampling filter paper discs (2.7 mm in diameter) containing the large amount of serum retained after a single spotting. Several oxidizers (sodium chlorate, sodium azide, acetic acid, formic acid, 1-butyl-3-methylimidazoliumm chloride/bromide) were tested (oxidizers premixed with the sample before spotting, and papers previously soaked in concentrated additive/oxidizer solutions). Direct multi-element determination (Al, Be, Ca, Cu, Fe, K, Li, Mg, Mn, Mo, Na, P, Rb, Se, V, and Zn) in dried serum spots at very low levels was therefore assessed by laser ablation (LA) coupled with inductively coupled plasma - mass spectrometry (ICP-MS). Laser ablation was performed using a focused Nd: YAG laser beam in lineal scan mode (wavelength 213 nm, laser fluency 2.2 J cm−2, repetition rate 20 Hz, laser spot diameter 90 µm, depth 0 µm, scanning speed 12 µm s−1). Matrix-matched calibration mode and 13C as internal standard (for signal intensities normalization) was used throughout the work. Limits of quantification were found to be from 21 µg L−1 to 221 mg L−1. Repeatability (seven ablations of the same dried serum spot) and reproducibility (two ablations of seven dried serum spot from the same material) offered RSDs below 12% for all analytes, which seems satisfactory for clinical purposes. The method was validated by analyzing several certified reference materials (Seronorm™ level I and II trace elements in serum), and it was applied to several DMS from serum samples from healthy adults.

A detection system based on Laser Induced Breakdown Spectroscopy (LIBS) was designed, optimized, and successfully employed for the estimation of lead (Pb) content in drilling fueled soil (DFS) collected from oil field drilling areas in Pakistan. The concentration of Pb was evaluated by the standard calibration curve method as well as by using an approach based on the integrated intensity of strongest emission of an element of interest. Remarkably, our investigation clearly demonstrated that the concentration of Pb in drilling fueled soil collected at the exact drilling site was greater than the safe permissible limits. Furthermore, the Pb concentration was observed to decline with increasing distance away from the specific drilling point. Analytical determinations were carried out under the assumptions that laser generated plasma was optically thin and in local thermodynamic equilibrium (LTE). In order to improve the sensitivity of our LIBS detection system, various parametric dependence studies were performed. To further validate the precision of our LIBS results, the concentration of Pb present in the acquired samples were also quantified via a standard analytical tool like inductively coupled plasma/optical emission spectroscopy (ICP/OES). Both results were in excellent agreement, implying remarkable reliability for the LIBS data. Furthermore, the Limit of detection (LOD) of our LIBS system for Pb was estimated to be 125.14 mg L-1.

One of the aims of this study was to improve the sample throughput of a microwave-assisted closed vessel digestion system by using small quartz vials in polytetrafluoroethylene (PTFE) vessels for the sample preparation of raw propolis samples in small amounts. The digested samples were measured by inductively coupled plasma optical emission spectrometry (ICP-OES) and inductively coupled plasma mass spectrometry (ICP-MS) analyzing 36 elements. Limit of detection was low enough to measure all the elements, with the exception of La, in all raw propolis samples. There were no cross-contamination between the quartz vials, therefore independent samples can be prepared in the same PTFE vessel. Accuracy of the method was checked by spike recoveries and by analyzing BCR 189 wholemeal flour and two plant samples from a collaborative study. The means of RSDs were 5.3%-14.4% in the case of measured elements. The sample throughput was increased by three times using quartz vials in PFTE vessels besides matching with the requirements of green chemistry. Another goal was the characterization of the element content and thereby geographical identification of Hungarian raw propolis. In total, 252 samples were analyzed and their statistical characteristics were described. We cannot find globally such results of propolis element content, which is representing one country and with such a number of elements and samples. All the elements have positive skew and positive kurtosis. Concentration range is above two orders of magnitude in the case of Ba, Zn, V, Cr, Ni, Cd and Eu elements. The decimal logarithm of element concentrations was used for geographical identification of raw propolis samples originating from seven regions of Hungary by linear discriminant analysis (LDA). Grouping of the samples of the Northern Great Plain was the most effective with 96.3% and 77.8% based on the original method and the cross validation, respectively. The same indicators for all the groups are 76.6% and 61.5%.

A systematic study of hydride generation (HG) of As, Bi, Sb and Se from solutions containing As(III), As(V), Bi(III), Sb(III), Sb(V), Se(IV) and Se(VI) was presented. Hydrides were generated in a gas-liquid phase separation system using a continuous flow vapor generation accessory (VGA) by mixing acidified aqueous sample, HCl and sodium borohydride reductant (NaBH4) solutions on-line. For detection, a simultaneous axially viewed inductively coupled plasma optical emission spectrometer (ICP-OES) was applied. Effects of the HCl concentration (related to sample and additional acid solutions) and type of the pre-reducing agents used for reduction of As(V), Sb(V) and Se(VI) into As(III), Sb(III) and Se(IV) on the analytical responses of As, Bi, Sb and Se were studied and discussed. Two compromised HG reaction conditions for simultaneous measurements of As+Bi+Sb (CC1) or As+Sb+Se (CC2) were established. It was found that choice of the pre-reductant prior to formation of the hydrides is critical in obtaining the dependable results of the analysis. Accordingly, for a As(III)+As(V)+Bi(III)+Sb(III)+Sb(V) mixture and using CC1, thiourea/thiourea-ascorbic acid interfered in Bi determination and hence, total As+Sb could be measured. If L-cysteine/L-cysteine-ascorbic acid were used, measurements of total Bi+Sb was possible in these HG reaction conditions. For a As(III)+As(V)+Sb(III)+Sb(V)+Se(IV)+Se(VI) mixture and using CC2, thiourea/thiourea-ascorbic acid and L-cysteine/L-cysteine-ascorbic acid influenced HG of Se but ensured total As+Sb determination. In contrast, heating a sample solution with HCl, although did not pre-reduce As(V) and Sb(V), assured quantitative reduction of Se(VI) to Se(IV). Finally, considering all favorable pre-reducing and HG conditions, methodologies for reliable determination of total As, Bi, Sb and Se by HG-ICP-OES were proposed. Strategies for single-, two- and three-element measurements were evaluated and validated, obtaining the detection limits (DLs) below 0.1ngg-1 and precision typically in the range of 1.4-3.9% RSD.

It is challenging to separate and measure the physical and chemical properties of monometallic and bimetallic engineered nanoparticles (NPs), especially when mixtures are similar in size and at low concentration. We report that single particle inductively coupled mass spectroscopy (SP-ICP-MS), alongside field flow fractionation (FFF), has allowed for the accurate measurement of size and particle number concentrations of mixed metallic nanoparticles (NPs) containing monometallic NPs of gold (Au) and silver (Ag) and a bimetallic core-shell structured NP (Au@Ag) of equivalent size. Two sets of these NPs were measured. The first contained only 60 nm particles, where the Au@Ag NP had a 30 nm core and 15 nm shell to make a total diameter of 60 nm. The second contained only 80 nm particles (Au@Ag NP core particle of 50 nm with a 15 nm shell). FFF separation was used here as a sizing technique rather than a separation technique. It was used to confirm that suspensions containing either individual or mixtures of the Au 60 nm, Ag 60 nm and AuAg 60 nm suspensions eluted together and were of the same size. Similarly, FFF was used to show that suspensions containing individual or mixtures of the equivalent 80 nm, eluted together and were of the same size. Although the 60 nm and 80 nm suspensions did not elute at the same time they were not run together. SP-ICP-MS is then used to identify the size and concentration of the particles within the suspension. Successful separation of the NPs was effected and the limits of the instrument were obtained.

Species-specific isotope dilution inductively coupled plasma quadrupole mass spectrometry reference method and high-performance liquid chromatography were applied for simultaneous determination of mercury species in marine samples. Different extraction protocols for mercury species were tested and evaluated. It was found that after exposure to microwave energy the inorganic mercury (iHg) and methyl mercury (MeHg) can be completely extracted from marine biota sample by 4.5 mol L−1 HCl as well as by 3.0 mol L−1 HNO3 and further separated with HPLC. The obtained results for iHg and MeHg in the IAEA-461 certified reference material (CRM) clam Gafrarium tumidum biota sample were as follow: (341 ± 21) μg kg−1 or (338 ± 15) μg kg−1 and (61.3 ± 2.2) μg kg−1 (recovery of (98.4 ± 3.6) %) or (61.1 ± 2.8) μg kg−1 (recovery of (98.1 ± 4.6) %), respectively when diluted HCl or HNO3 were applied in the extraction step. However, these protocols are not applicable to marine sediment samples, where the iHg is the predominant form. Therefore, one selective extraction procedure for MeHg from sediment was applied to make possible its separation and quantification. This procedure consisted of series of subsequent extraction steps at room temperature: first with a mixture of H2SO4/KBr/CuSO4, next with organic solvent dichloromethane and as a final step one back-extraction with Na2S2O3 solution. The combination of the selective extraction with the ID calibration approach was found to be an efficient way for the simultaneous determination and separation of both MeHg and iHg species in one chromatographic run. The proposed procedure was successfully used for the determination of mercury species in the IAEA-405 sediment CRM and further applied for the simultaneous measurements of iHg and MeHg in a candidate CRM – the IAEA-475 sediment sample. The determined mass fractions were (30.1 ± 1.6) μg kg−1 and (196 ± 8) ng kg−1 for iHg and MeHg, respectively. The difference between obtained in this study results and those from the reference IAEA-475 values was 1.5% and further validated the developed in this study analytical methodology. To the best of our knowledge, this selective procedure for MeHg extraction was never used before for the simultaneous quantification of mercury species in marine sediment.

A novel amine- and carboxyl-bifunctionalized organic-inorganic hybrid monolithic column (A&C-HMC) was synthesized via one-pot co-condensation of N-(2-aminoethyl)-3-aminopropyltriethoxysilane, carboxyethylsilanetriol sodium salt and tetramethoxysilane with cetyltrimethylammonium bromide and polyethylene glycol 6000 as binary porogens in this work. The introduction of the binary porogens controllably improved the morphology and pore structure of A&C-hybrid monolith (HM) and made the active sites of amine and carboxyl groups more prolific, compared with the monolith prepared with either of porogens. It is found that Cr(VI) and Cr(III) can be selectively adsorbed on A&C-HM under different pH ranges, and eluted by aqueous nitric acid solution completely. The A&C-HMC was used as needle-solid phase microextraction (SPME) matrix for direct separation and enrichment of inorganic chromium species coupled with inductively coupled plasma mass spectrometer without any oxidation/reduction treatment. Various parameters of SPME operation and analytical performance were investigated systematically, and the adsorption mechanism was also discussed and explained in depth. In view of the advantages of facile preparation, low cost, excellent speciation selectivity and high adsorption capacity to Cr(VI) and Cr(III), the A&C-HMC based SPME protocol is a promising alternative for non-disturbed speciation analysis of inorganic chromium in real environmental water samples.

The aim of this study was to develop a method for the separation of oxaliplatin enantiomers at attomolar concentration levels. A combination of capillary electrophoresis and inductively coupled plasma mass spectrometry was chosen due to their unique characteristics, including fast and easy modification of separation selectivity, and significant limits of detection and linearity. In the first step, we optimized conditions for the separation of oxaliplatin enantiomers including background electrolyte composition and concentration, pH, and type and concentration of the chiral selector. Under optimal conditions, sodium borate buffer pH 9.5, ionic strength 40 mmol L−1, with 60 mg mL−1 sulfated β-cyclodextrin, separation was obtained with a resolution of 2.0. This electrolyte system was then used in the ‘in-house’ connection of capillary electrophoresis with inductively coupled plasma mass spectrometer. In this instance, separation lasted for 9.5 min. Calibrations were linear in the range of 0.1–500 μg mL−1 with R2 of 0.9999. LOD and LOQ values were of 64 ng mL−1 and 116 ng mL−1 of oxaliplatin, respectively. This represents detection of 49 fg or 125 attomol of oxaliplatin enantiomers in the capillary electrophoresis injected sample zone. Finally, the method was successfully applied for detection of oxaliplatin enantiomers in spiked urine samples.

Particulate matter (PM) is the major environmental pollutant. Its elemental composition is routinely monitored. Inductively coupled plasma mass spectroscopy (ICPMS) is commonly applied after a PM sample has been digested by an acid during a microwave treatment. In this case, sample preparation procedure is laborious, sometimes incomplete and produces toxic waste. In this paper we show that direct sample introduction to ICPMS by laser ablation (LA-ICPMS) is of huge advantage. Minimal quantity of a sample is required for the analysis (

An online separation and preconcentration method, employing a lab-on-valve system using solid phase extraction, followed by inductively coupled plasma tandem mass spectrometry (ICP-MS/MS), was developed for the analysis of 90Sr. The 90Sr was separated from 90Zr, an isobaric interference present at high concentrations in many samples, and other matrix components using a dual-column setup (Eichrom DGA-B and Sr resins). Any remaining 90Zr was then chemically resolved from the 90Sr in the ICP-MS/MS using O2 and H2 reaction gases. The system requires small sample volumes (10 mL), minimal sample preparation compared to traditional radiometric and other MS techniques and has a processing time of 22 min per sample. Based on a 10 mL sample size, the system limit of detection, limit of quantification and method detection limit (MDL) were 0.47 Bq L−1 (0.09 pg L−1), 1.57 Bq L−1 (0.32 pg L−1) and 1.79 Bq L−1 (0.34 pg L−1), respectively. The robustness of the system and suitability for use in various sample matrices was demonstrated using spiked lake water, spiked groundwater, spiked seawater and radioactive water samples. Recovery of the IAEA 2018 Proficiency Test Exercise water sample (n = 5) was 99% with an RSD of 11.9%. The method thus provides a powerful tool for the rapid analysis of low levels of 90Sr in various water/wastewater samples.

This work describes a procedure using the recently proposed standard dilution analysis (SDA) calibration method for the determination of As, Cr and Ni in concentrated HNO 3 and HCl by inductively coupled plasma tandem mass spectrometry (ICP-MS/MS). Because of the low contaminant levels, and consequently low limits of detection required for these reagents (commonly used in trace element analysis and the semiconductor industry), samples were minimally diluted. The analysis of concentrated acids can result in matrix/transport effects, which may compromise accuracy in ICP-MS determinations. High-chlorine content samples are also challenging for As and Cr determination due to the formation of polyatomic species such as 40 Ar 35 Cl + and 35 Cl 16 OH + , which overlap the only As isotope, 75 As + , and the main Cr isotope, 52 Cr + , respectively. The combination of SDA and ICP-MS/MS was evaluated to overcome matrix, transport and spectral interferences in order to increase accuracy, precision and sample throughput. The performance of SDA was compared with the traditional methods of external standard calibration (EC), internal standardization (IS), and standard additions (SA). The limits of detection for SDA were calculated as 6, 10, and 30 ng L −1 for As, Cr, and Ni, respectively. Recoveries for spike experiments using the new method were in the 90–114% range for all analytes. The procedure described here provides similar or even better analytical performance in comparison with EC, IS and SA.

In this study, a functionalized magnetic hollow porous oval-shape NiFe2O4 (MHPO-NiFe2O4) was designed by a facile synthesis procedure, and employed as magnetic solid phase extraction (MSPE) material to extract several heavy metal ions. As-prepared MHPO-NiFe2O4 exhibited superior adsorption capacities of 20.17, 16.64, 16.82, 9.69 and 16.58 mg g−1, for Cu(II), Cd(II), Cr(III), Co(II) and Zn(II), and was then used to detect these heavy metals elements in real samples by combining with inductively coupled plasma optical emission spectroscopy (ICP-OES). The possible mechanism of the enrichment of heavy metals ions on MHPO-NiFe2O4 was proposed, which involved the dominant adsorption and desorption. The detection limits were as low as 0.015, 0.13, 0.062, 0.035 and 0.46 μg L−1 for Cu(II), Cd(II), Cr(III), Co(II) and Zn(II), respectively. A good repeatability was obtained with the relative standard deviation (RSD) of 3.87%. Moreover, the method was successfully utilized for the analysis of five heavy metals in real samples (cabbage, lettuce, apple, seawater), with satisfactory recoveries in the range of 92–108%.

The analytical procedures for reference measurements of the total Hg and methyl mercury (MeHg) mass fractions at various concentration levels in marine biota samples, candidates for certified reference materials (oyster and clam Gafrarium tumidum), were evaluated. Two modes of application of isotope dilution inductively coupled plasma mass spectrometry method (ID ICP-MS), namely direct isotope dilution and species-specific isotope dilution analysis with the use of two different quantification mass spectrometry techniques were compared. The entire ID ICP-MS measurement procedure was described by mathematical modelling and the combined uncertainty of measurement results was estimated. All factors influencing the final results as well as isotopic equilibrium were systematically investigated. This included the procedural blank, the moisture content in the biota samples and all factors affecting the blend ratio measurements (instrumental background, spectral interferences, dead time and mass discrimination effects as well as the repeatability of measured isotopic ratios). Modelling of the entire measurement procedures and the use of appropriate certified reference materials enable to assure the traceability of obtained values to the International System of Units (SI): the mole or the kilogram. The total mass fraction of mercury in oyster and clam biota samples, after correction for moisture contents, was found to be: 21.1 (1.1) 10(-9) kg kg(-1) (U =5.1% relative, k=2) and 390.0 (9.4) 10(-9) kg kg(-1) (U=2.4% relative, k=2), respectively. For the determination of mercury being present as methyl mercury, the non-chromatographic separation on anion-exchange resin AG1-X8 of the blended samples was applied. The content of MeHg (as Hg) in oyster sample was found: 4.81 (24) 10(-9)kgkg(-1) (U=5.0%, k=2) and 4.84 (21) 10(-9)kgkg(-1) (U=4.3%, k=2) with the use of quadrupole (ICP QMS) or sector field (ICP SFMS) inductively coupled plasma mass spectrometers, respectively. In the case of clam sample, the concentration of MeHg (as Hg) was found to be: 61.0 (2.3) 10(-)(9)kgkg(-1) (U=3.8%, k=2) and 61.3 (2.2) 10(-)(9)kgkg(-1) (U=3.6%, k=2), respectively. The mass fractions for total Hg and MeHg determined in this study were used as a contribution of the International Atomic Energy Agency (IAEA) Environment Laboratories in the characterisation of the IAEA 461 and IAEA 470 certified reference materials. The obtained good agreement with the reference values further validated the methods developed in this study.

A rapid and effective suspended dispersive solid phase microextraction (SDSPME) was developed for the speciation of inorganic selenium using alumina nanoparticles functionalized with Aliquat-336. The target analytes were preconcentrated and determined by inductively coupled plasma optical emission spectrometry. Alumina nanoparticles were characterized using XRD, BET, SEM and EDX while the functionalized nano-Al2O3 was characterized by FTIR. The effect of pH of the solution on speciation Se in water samples was optimized separately. It was observed that when the pH values of sample solution ranged from 2.0 to 7.0, successful separation of inorganic Se species was achieved. The percentage recoveries for Se (IV) and Se (VI) were >90% and 5%, respectively. The two-level fractional factorial design was used to optimize experimental parameters affecting the preconcentration system. Under optimal conditions, the enrichment factor (EF), limit of detection (LOD) and limit of quantification for Se (IV) were found to be 850, 1.4ngL(-1,) and 4.6ngL(-1), respectively. Furthermore, intra-day and inter-day precisions expressed in terms of relative standard deviation (RSD) were found to be 1.9% and 3.3%, respectively. The effect of coexisting ions on the recovery of Se (IV) was investigated. The accuracy of the developed method was checked by analysis of standard reference material (NIST SRM 1643e). The optimized method was applied for the determination of targets in surface water samples.

An improved matrix separation method has been described to characterize ultrapure germanium of 8N (99.999999%) purity. In this method, temperature of the reaction vessel in which in-situ generated chlorine gas reacts with germanium solid material directly is optimized to quantitatively remove Ge matrix from all its impurities. Optimized reaction temperature has been found to be 230±5°C. Recovery studies on more than 60 elements have been carried out at the optimized temperature. Recoveries of all the analytes except As, Se, Sn, Hg, Tl are found to be quantitative. The method has been examined for various amounts of Ge material and found to be suitable even for 10g of Ge sample and provides low parts per billion and trillion levels of process blanks. Determination of concentrations of impurities has been done by inductively coupled plasma quadrupole mass spectrometer (ICP-QMS) and high resolution continuum source graphite furnace atomic absorption spectrometer (HR-CS-GFAAS). In the absence of certified reference materials for ultrapure germanium, accuracy of the proposed method is established by spike recovery tests. Precision of this method is found to vary from 7% to 50% for concentrations between 4 and 0.004ngg(-1). Limits of detection (LOD) for the target analytes are found to be between 6 and 0.011ngmL(-1) or 1.8-0.003ngg(-1) for the proposed procedure. The method has been successfully applied for that characterization of ultrapure germanium material of 8N purity.

This paper describes the potential of high-resolution continuum source graphite furnace atomic absorption spectrometry for determination of Pt, Pd and Rh after separation and concentration by original in-house developed heterochain polymer S, N-containing sorbent. The methods of sample preparation of spent ceramic-based autocatalysts were considered, two of which were used: autoclave decomposition in mixture of acids HCl:HNO3 (3:1) and high-temperature melting with K2S2O7. Both methods anyway limit the direct determination of analytes by HR CS GFAAS. Using the first method it is an incomplete digestion of spent autocatalysts samples, since the precipitate is Si, and the rhodium metal dissolves with difficulty and partially passes into solution. In contrast to the first method, the second method allow to completely transfer analytes into solution, however, the background signal produced by the chemical composition of the flux, overlaps the analytical zone. It was found, that Pt, Pd and Rh contained in the spent ceramic automotive catalysts could be effectively separated and concentrated by heterochain polymer S, N-containing sorbent, which has high sorption capacity, selectivity and resistant to dilute acids. The chosen HR CS GFAAS analysis conditions enable us to determine Pt, Pd and Rh with good metrological characteristics. The concentrations of Pt, Pd and Rh in two samples of automobile exhaust catalysts were found in range of 0.00015-0.00050; 0.170-0.189; 0.0180-0.0210wt%, respectively. The relative standard deviation obtained by HR CS GFAAS was not more than 5%. Limits of detection by HR CS GFAAS achieved were 6.2·10(-6)wt% for Pt, 1.8·10(-6)wt% for Pd, and 3.4·10(-6)wt% for Rh. Limits of determination achieved by HR CS GFAAS were 1.1·10(-5)wt% for Pt, 6.9·10(-5)wt% for Pd, and 8.3·10(-5)wt% for Rh. To control the accuracy of PGM in sorption concentrates by HR CS GFAAS method, it was appropriate to conduct an inter-method comparative experiment. The researches on the application of atomic-emission spectroscopy method with inductively coupled plasma as a comparative method were conducted. In addition, the trueness control of the obtained results is confirmed by added-found method.

The paper presents a combined technique of germanium dioxide analysis by inductively coupled plasma atomic emission spectrometry (ICP-AES) with preconcentration of trace elements by distilling off matrix and electrothermal (ETV) introduction of the trace elements concentrate into the ICP. Evaluation of metrological characteristics of the developed technique of high-purity germanium dioxide analysis was performed. The limits of detection (LODs) for 25 trace elements ranged from 0.05 to 20ng/g. The accuracy of proposed technique is confirmed by "added-found" («or spiking») experiment and comparing the results of ETV-ICP-AES and ICP-AES analysis of high purity germanium dioxide samples.