ICP-MS Detection Research Articles

Unveiling New Arsenic Compounds in Plants via Tailored 2D-RP-HPLC Separation with ICP and ESI MS Detection.

Arsenic (As) speciation analysis is scientifically relevant due to the pivotal role the As chemical form plays in toxicity, which, in turn, directly influences the effect it has on the environment. The objective of this study was to develop and optimize a method tailored for studying As compounds in plant samples. Different extraction procedures and HPLC methods were explored to assess their efficiency, determine mass balance, and improve the resolution of compounds in the chromatograms. Conventionally applied anion-exchange chromatography facilitated the separation of well-documented As compounds in the extracts corresponding to 19 to 82% of As present in extracts. To gain insight into compounds which remain undetectable by anion chromatography (18 to 81% of As in the extracts), but still possibly metabolically relevant, we explored an alternative chromatographic approach. The procedure of sample purification and preconcentration through solid-phase extraction, facilitating the detection of those minor As compounds, was developed. The system was further refined to achieve an online 2D-RP-HPLC system, which was employed to analyze the extracts more comprehensively with ICP and ESI MS. Using this newly developed method, As(III)-phytochelatins, along with other arseno-thio-compounds, were detected and identified in extracts derived from the tree roots of seedlings grown in the presence of As(III) and As(V), and a group of arseno lipids was detected in the roots of plants exposed to As(V).

Discovery of an unusual copper homeostatic mechanism in yeast cells respiring on minimal medium and an unexpectedly diverse labile copper pool

Copper is essential for all eukaryotic cells but many details of how it is trafficked within the cell and how it is homeostatically regulated remain uncertain. Here, we characterized the copper content of cytosol and mitochondria using liquid chromatography with ICP-MS detection. Chromatograms of cytosol exhibited over two dozen peaks due to copper proteins and coordination complexes. Yeast cells respiring on minimal media did not regulate copper import as media copper concentration increased; rather, they imported copper at increasing rates while simultaneously increasing the expression of metallothionein CUP1 which then sequestered most of the excessive imported copper. Peak intensities due to superoxide dismutase SOD1, other copper proteins, and numerous coordination complexes also increased, but not as drastically. The labile copper pool was unexpectedly diverse and divided into two groups. One group approximately comigrated with copper-glutathione, -cysteine, and -histidine standards; the other developed only at high media copper concentrations and at greater elution volumes. Most cytosolic copper arose from copper-bound proteins, especially CUP1. Cytosol contained an unexpectedly high percentage of apo-copper proteins and apo-coordination complexes. Copper-bound forms of non-CUP1 proteins and complexes coexisted with apo-CUP1 and with the chelator BCS. Both experiments suggest unexpectedly stable-binding copper proteins and coordination complexes in cytosol. COX17Δ cytosol chromatograms were like those of WT cells. Chromatograms of soluble mitochondrial extracts were obtained, and mitoplasting helped distinguish copper species in the intermembrane space versus in the matrix/inner membrane. Issues involving the yeast copperome, copper homeostasis, labile copper pool, and copper trafficking are discussed.

Chemical degradation of platinum oncolytics in urine and speciation of the inorganic contaminants cisplatin and carboplatin relevant in waste water

Understanding the prevalent form of platinum (Pt) based antineoplastic agents, used in chemotherapy, is of importance to develop a remediation strategy that restricts aquatic exposure. The speciation of Pt-based compounds was measured in actual patients’ urine using hydrophobic interaction liquid chromatography (HILIC) equipped with an ICP-MS detector. Carboplatin showed poor metabolization and intact excretion 11 h after administration, whereas cisplatin underwent a rapid aquation in the first 7 h. To compare, the in vitro degradation rate of cisplatin, carboplatin and oxaliplatin was determined in synthetic human urine, mimicking true environmental conditions. The fraction of intact molecules was measured at regular intervals following incubation at 37 °C, resulting in degradation rate constants. The chemical stability was highest for carboplatin (k = 0.0143 ± 0.0012 min−1), versus faster degradation of oxaliplatin and cisplatin by exponential decay with k1 of 0.0026 ± 0.0001 min−1 and k2 = 5.59 ± 0.46 × 10−6 min−1, respectively. These kinetic parameters can serve as input to further expand modelling databases and improve the predictive power of speciation software to estimate eco-toxicity risks. Considering the strong residual cytotoxicity of the platinum antineoplastic molecules following renal clearance and human excretion, the contaminants are of high environmental concern and offer potential for metal recovery using advanced treatment steps. In such water treatment processes, especially carboplatin, above all cancerostatic platinum compounds, should be addressed since it is more persistent in the aquatic environment.

Fabrication of Spiny-like Spherical Copper Metal–Organic Frameworks for the Microextraction of Arsenic(III) from Water and Food Samples before ICP-MS Detection

Spiny-like spherical copper metal–organic frameworks (SSC-MOFs) were prepared and characterized via SEM, TEM, EDS, XRD, FTIR and the BET surface area. The fabricated SSC-MOFs were applied to develop a procedure for the microextraction of trace arsenic(III) for preconcentration. The results show that a copper- and imidazole-derived metal–organic framework was formed in a sphere with a spiny surface and a surface area of 120.7 m2/g. The TEM confirmed the perforated network structures of the SSC-MOFs, which were prepared at room temperature. The surface functional groups were found to contain NH and C=N groups. The XRD analysis confirmed the crystalline structure of the prepared SSC-MOFs. The application for the process of microextracting the arsenic(III) for preconcentration was achieved with superior efficiency. The optimum conditions for the recovery of the arsenic(III) were a pH of 7 and the use of a sample volume up to 40 mL. The developed SSC-MOF-derived microextraction process has an LOD of 0.554 µg·L−1 and an LOQ of 1.66 µg·L−10. The developed SSC-MOF-derived microextraction process was applied for the accurate preconcentration of arsenic(III) from real samples, including food and water, with the promised performance efficiency.

Chemo‐trapping method for determination of volatile arsenic from paddy soil

AbstractThe objective of this study was to develop a technique for collecting and analyzing volatile arsenic species including arsine (AsH3), methyl arsine (CH3AsH2), dimethyl arsine (CH3)2AsH, and trimethyl arsine (CH3)3As emitted from paddy soil. The four volatile arsenic species were captured on AgNO3‐impregnated sand then eluted and quantified. The AgNO3‐impregnated sand was synthesized by crystallizing AgNO3 on 0.5‐1 mm id. sandy particles at 70 oC. The volatile arsenic species were generated by hydride a mixture containing sodium arsenous (NaAsO2), disodium methyl arsenate ((CH3AsO(ONa)2), sodium cacodylate ((CH3)2AsO(ONa)), and trimethyl arsine oxide ((CH3)3AsO) using NaBH4. The formed volatile arsenic species were purged with an Ar stream then retained on a trap packed with the AgNO3‐impregnated sand followed by elution with 2 mL of 2.5% nitric acid and 0.5 mL of 30% H2O2 at 70oC prior to total analysis by ICPMS and speciation analysis by ion exchange chromatography ‐ ICPMS. The total analysis of arsenic revealed that AgNO3‐impregnated sand can efficiently retain the four volatile arsenic with 91‐102% recovery within a range of 20‐2000 ngAs as total amounts. The detection limit for total arsenic species through the trap was 6.5 ngAs. For a trap packed with 300 mg of AgNO3‐impregnated sand, the capture capacity was greater than 2000 ngAs. The speciation of arsenic eluted from the trap was performed by separation on a Hamilton PRP‐X100 anion‐exchange column with gradient elution using 100 mM (NH4)2CO3 mobile phase followed by ICPMS detection. A pot experiment was conducted to evaluate the efficiency of the purge and trapping method for naturally formed volatile arsenic species emitted from flooded paddy soil. Preliminary results showed that methyl arsenic, trimethyl arsenic and arsine were emitted from the studied paddy soil in which arsine contributes 90% of arsenic emission. This method is showing promise to be applied for the emission of volatile arsenic analysis from paddy soil as well as other solid types of samples.

Thiophene Functionalized Magnetic Covalent Organic Frameworks For Selective Extraction Of Trace Heavy Metals Followed By ICP-MS Detection

Thiophene Functionalized Magnetic Covalent Organic Frameworks For Selective Extraction Of Trace Heavy Metals Followed By ICP-MS Detection

Non-ceruloplasmin-bound copper and copper speciation in serum with extraction using functionalized dendritic silica spheres followed by ICP-MS detection

The quantification of non-ceruloplasmin-bound copper (NCBC) and total copper in biological fluids is highly required for understanding the correlation of copper with various physiological processes and diseases. In the present work, we developed dendritic spherical silica particles functionalized with EDTA, shortly as DMSPs-EDTA, from the hydrolysis of tetraethyl orthosilicate with the aid of structure-directing agents and subsequent modification of EDTA. DMSPs-EDTA serves as adsorbent with abundant binding sites to facilitate efficient extraction of NCBC. The retained NCBC on DMSPs-EDTA may be readily recovered by stripping with HNO3 (2 mol L−1). By hyphenating with ICP-MS detection, it provides a limit of detection of 1.3 pmol for NCBC. The degradation of ceruloplasmin with 200 mmol L−1 H2O2 releases the bound copper as NCBC to distribute among other ligands, which may be efficiently retained by the adsorbent and facilitate the detection of total copper. The linear ranges of 0.21–10 μmol L−1 and 0.42–30 μmol L−1 were derived for the detection of NCBC and total copper. The recovery rates for spiked NCBC or total copper in serum were derived to be 97–108% and 94–102%, respectively. The analysis of serum for a healthy subject resulted in 1.8 μmol L−1 NCBC and 9.5 μmol L−1 total copper. In addition, the proportions of 8.5–12% for NCBC were derived from the serum of healthy adults, while those for the patients with lung, hepatocellular and esophageal carcinoma were found to be 10–12%, illustrating no obvious difference against the normal group.

Terpyridine copper(II) complexes as potential anticancer agents by inhibiting cell proliferation, blocking the cell cycle and inducing apoptosis in BEL-7402 cells.

Four mononuclear terpyridine complexes [Cu(H-La)Cl2]·CH3OH (1), [Cu(H-La)Cl]ClO4 (2), [Cu(H-Lb)Cl2]·CH3OH (3), and [Cu(H-Lb)(CH3OH)(DMSO)](ClO4)2 (4) were prepared and fully characterized. Complexes 1-4 exhibited higher cytotoxic activity against several tested cancer cell lines especially BEL-7402 cells compared to cisplatin, and they showed low toxicity towards normal human liver cells. ICP-MS detection indicated that the copper complexes were accumulated in mitochondria. Mechanistic studies demonstrated that the copper complexes induced G0/G1 arrest and altered the expression of the related proteins of the cell cycle. All copper complexes reduced the mitochondrial membrane potential while increasing the intracellular ROS levels and the release of Ca2+. They also up-regulated Bax and down-regulated Bcl-2 expression levels, caused cytochrome c release and the activation of the caspase cascade, and induced mitochondrion-mediated apoptosis. Animal studies demonstrated that complex 1 suppressed tumor growth in a mouse xenograft model bearing BEL-7402 tumor cells.

Detailed evaluation of conditions of photochemical vapor generation for sensitive determination of nickel in water samples by ICP-MS detection

Photochemical vapor generation (PVG) of Ni was optimized using inductively coupled plasma mass spectrometry detection and a 19 W high-efficiency flow-through photoreactor operated in a flow injection mode (0.49 mL sample volume). The main aim was to achieve very high sensitivity and low limits of detection (LOD) for determination of Ni in fresh water samples, which necessitated to keep low Ni contamination and rather low dilution of samples by added formic acid as a photochemical agent. With respect to that a reaction medium composed of 30% (m/v) formic acid and a flow rate through the photoreactor of 1.5 mL min−1, which corresponds to an irradiation time of 29 s, were chosen as optimal. These PVG conditions were characterized by 42% overall PVG efficiency and by relative and absolute LOD of 1.9 ng L–1 and 0.9 pg, respectively. Almost double efficiency was achievable when pH was adjusted by an addition of 1.5 M ammonium formate, reflected in the proportional increase in sensitivity. However, no significant benefit to analytical performance was found at those conditions. Interferences from inorganic anions likely to be encountered during analytical application to real samples (i.e., NO3−, Cl−, SO42−) were investigated in detail as well as interferences from several transition metals and metalloids. The accuracy was successfully verified by an analysis of the standard reference material NIST 1643f (fresh water) and certified reference materials SLRS-6 (river water), ERM-CA713 (wastewater) and CTA-FFA-1 (fine fly ash), the last one after simple acid digestion. The applicability of this sensitive methodology was further demonstrated by a direct analysis of three water samples (river and well) that were collected and only acidified with formic acid to 30% (m/v).

Chip-based microfluidics on-line with inductively coupled plasma - mass spectrometry for standard dilution analysis

Microfluidics coupled on-line with ICP-MS detection can be combined with powerful quantitation procedures that take advantage of internal standardization and standard additions, such as the recently introduced Standard Dilution Analysis (SDA). Although so far used at mL min−1 flow rates, here we demonstrate that SDA can be conveniently employed with a microfluidic chip-based ICP-MS system to improve determination accuracy for various sample types, including water, biological and cell digest samples, analyzed at μL min−1 flow rates. The efficient coupling of a microfluidic chip to ICP-MS was accomplished using a combination of commercially available components, including a pneumatic high-efficiency nebulizer and a spray chamber designed to allow for the addition of a laminar flow makeup gas. The addition of the makeup gas was crucial in order to avoid detrimental suction effects that can disrupt the operation of the microfluidic chip and cause signal instability, while it still allowed for the highly sensitive detection of metal isotopes by using ICP-MS. All mixing and dilution operations of the sample with the two calibration solutions required for SDA were performed in an automated and highly reproducible fashion on the microfluidic chip with the assistance of an external distributor valve. High average recoveries (97.4–100.1%) and low average relative standard deviations (2.9–4.8%) were achieved for the determined elements (Cd, Co, Pb, Cr) across several spiked matrices and certified reference materials, whereas only 140 μL of sample is required for SDA in triplicate or 40 μL for a single analysis. Hence, accuracy, precision, limited sample consumption, and the elimination of the need for manual sample dilution and mixing manipulations are some of the advantages of this newly developed chip-based microfluidic SDA ICP-MS technique.

Speciation analysis of mercury employing volatile species generation: Approaches to reliable determination in blood and hair

Two approaches to Hg speciation analysis, both employing volatile species generation (VSG) were optimized and subsequently applied to biological sample analysis. The first one employs post-column VSG after HPLC separation of Hg species (Hg2+, MeHg+, EtHg+ and PhHg+) prior to their ICP-MS detection (HPLC-VSG-ICP-MS). The optimized post-column VSG step enhances sensitivity 30–40 times and improves limits of detection (LOD) by a factor of five in comparison with the setup without VSG step (HPLC-ICP-MS). LODs between 3 and 6 ng L−1 have been reached by HPLC-VCG-ICP-MS while those reached by HPLC-ICP-MS ranged significantly higher (15–26 ng L−1). Additionally, the VSG step reduces significantly the effect of organic mobile phase on ICP plasma during gradient elution required for PhHg+ determination. Moreover, a simple and short (7 min) two-stage extraction procedure was proposed for simultaneous determination of Hg2+, MeHg+ and EtHg+ in human blood. Acceptable extraction efficiency of Hg species without their inter-conversions was confirmed by Hg speciation analysis in human blood certified reference materials (Seronorm Trace Elements Whole Blood L-1 and L-2) resulting in recoveries better than 90% (Hg2+, MeHg+) and 80% for EtHg+, respectively. The second approach to Hg speciation analysis is based on selective extraction of MeHg+ from hair samples with 2 mol L−1 HCl. Extraction selectivity was verified by HPLC-ICP-MS employing the IAEA-086 certified reference material of human hair. Three spectrometric detectors were compared for subsequent Hg determination in the extracts from hair including single purpose mercury analyzer AMA-254, VSG-AAS and ICP-MS resulting in MeHg+ recovery of 100 ± 10%.

Relative importance of organic- and iron-based colloids in six Nova Scotian lakes

Dissolved organic matter (DOM) concentrations have been increasing in parts of the northern hemisphere for several decades. This process—brownification—often accompanies increasing iron and aluminum, but the metal–DOM interactions these concurrent trends imply are poorly described. Here we used field-flow fractionation with UV and ICP-MS detection to measure the size distribution of colloidal iron, aluminum, manganese, copper, uranium, and chromophoric DOM in six lakes over six months. Five of these lakes have browned to some degree in the past three decades, with linear increases in organic carbon and color ranging from 0.01 to 0.13 mg C L−1 yr−1 and 0.13–1.94 PtCo yr−1. Browning trends were more pronounced and colloids more abundant in lakes with wetlands in their catchments. Iron and aluminum were present in two primary fractions, sized nominally at 1 and 1000 kDa. The 1 kDa fraction included the primary DOM signal, while the 1000 kDa fraction absorbed minimally at 254 nm and likely represents iron-rich (oxyhydr)oxides. Colloidal manganese was sized at 1000+ kDa, whereas colloidal copper and uranium occurred primarily at 1 kDa. These associations fit with a pattern of increasing DOC, iron, aluminum, and color in the region’s lakes. They represent a significant challenge for drinking water treatment systems, especially those in remote communities. Given that browning trends are expected to continue, monitoring plans would better inform treatment process design and operation by characterizing DOM and iron-rich, primarily inorganic colloids that contribute to adverse water quality outcomes.

Characterization of volcanic ash nanoparticles and study of their fate in aqueous medium by asymmetric flow field-flow fractionation-multi-detection.

Dimensional and elemental characterization of environmental nanoparticles is a challenging task that requires the use of a set of complementary analytical methods. Asymmetric flow field-flow fractionation coupled with UV-Vis, multi-angle laser light scattering and ICP-MS detection was applied to study the nanoparticle fraction of a volcanic ash sample, in a Milli-Q water suspension at pH 6.8. It has been shown that the separated by sedimentation nanoparticle fraction of the Klyuchevskoy volcano ash suspension contains 3 polydisperse populations for which size ranges (expressed in gyration radius, rG), hydrodynamic behaviours (evaluated via shape index) and elemental compositions are different. These 3 populations did not dissolve over the 72-h study but aggregated and settled out differently. Thus, the population of particles with gyration radii <140 nm (P1), which contained 6% Al2O3 and represented approximately 20% by mass of the nanoparticle fraction, remained in suspension without observable aggregation. The populations P2 and P3, which represented 67% and 13% by mass in the initial suspension, covered the rG range 25-250 nm and contained 17% and 15% Al2O3, respectively. Over time, populations P2 and P3 aggregated and their concentration in suspension at 72 h decreased by approximately 40% compared with the initial suspension. The decrease of these nanoparticle populations occurred either from the beginning of the temporal monitoring (P2) or after 30 h (P3). Aggregation generated a new population (P4) in suspension with rG up to 300 nm and mostly consisting of P2. This population represented only up to 6 to 7% of the nanoparticle fraction and decreased beyond 50 h. As a result, the trace elements present in the nanoparticle fraction and monitored (Cu and La) were also no longer found in the suspension. The results obtained can offer additional insights into the fate of volcanic ash nanoparticles in the environment.

Geochemical phases of soil and the bioaccessibility of some elements in soils and vegetables from boron mines.

The bioaccessibility of some elements (As, B, Cd, Cu, Fe, Mn, Ni and Zn) in soils and vegetables was determined using the physiologically based extraction test. An investigation of the geochemical phases of soils through sequential extraction methods followed by ICP-MS detection was also undertaken. Samples were collected from Iskele, Begendikler and Yolbasi villages in the Bigadic region and Yildiz village in the Susurluk region of Balikesir province, Turkey. All of these villages are close to boron mines. Principal component analysis and correlation analysis demonstrated the interrelationship between the bioaccessibility values of these elements in the gastric and intestinal extracts of soils as well as the plant samples grown in those soils and the elements' concentrations in the different soil fractions. From the bioaccessible concentrations of the elements in the intestinal phases, it was shown that the amounts of As, B, Cu, Mn and Ni in some plant samples were higher than the recommended and tolerable values for human consumption. The bioaccessibilty of these elements in the soils and plants were statistically related with the concentrations of these elements in the labile phases of the soil. The methodology adopted here would be applicable to determining interactions between elements and soil fractions and the interrelationships between bioaccessibility data and soil fractions for any soil samples.

Zirconium Interferences on the Detection of Silver Nanoparticles by Single Particle ICP-MS: Implications on Natural Water Analysis

The analysis of silver nanoparticle (NP Ag) by the single particle technique with argon plasma-coupled mass spectrometry (SP-ICP-MS) is an increasingly used analytical approach. The sensitive technique, distinguishing particle size distribution, allows working at concentrations similar to those found in environmental samples. The two natural Ag isotopes 107 and 109, with abundances of 52 and 48% respectively, have similar sensitivity in ICP-MS detection. However, it is common to encounter isobaric interferences in mass spectrometry, and the element silver is not an exception, as much with the 107 isotope as 109. For both isotopes, zirconium oxides present isobaric interferences, either 91Zr16O, 90Zr16O1H for the isotope 107 and the 92Zr16O1H for the 109. For surface water analysis by ICP-MS in regular technique, these interferences do not generally affect the analysis of total Ag concentrations as they can be then simply subtracted. On the other hand, detection of NP Ag was impacted by the interfering colloidal Zr. The analysis of Zr by the SP-ICP-MS technique of surface waters showed the presence of colloidal Zr, a random signal that cannot be simply subtracted from NP Ag signal. Our results showed that Zr colloids are effectively interfering with the NP Ag assays by SP-ICP-MS technique where interferences translated into a false positive. We proposed a calculation to evaluate a confidence threshold defining the maximum size that the false positives induced by Zr particles have on the silver particle detection. The analytical issue related to isobaric interferences from the naturally occurring colloidal Zr was attenuated by the use of the 109 isotope in the Ag particle detection, limiting false positive detections and improving the reliability of NP Ag measurements in natural waters. Therefore, more specific detection of NP Ag in surface waters that naturally contain Zr colloids can be accomplished.

Field-based Speciation of Inorganic Sb Using Ion-exchange Resin Cartridge and ICP-MS Detection

Field-based Speciation of Inorganic Sb Using Ion-exchange Resin Cartridge and ICP-MS Detection

Quantitative imaging of structured complex metal oxide thin films using online-LASIL-ICP-MS

Online-laser ablation of solids in liquid (online-LASIL) coupled with ICP-MS detection was used as a new sampling strategy for the analysis of complex metal oxide (CMO) thin films. The in-house built and optimized online-LASIL ablation cell provides the unique possibility to correlate the signal intensities with the spatial origin of the signal at the sample. For that purpose a particle transport with as little particle dispersion as possible is crucial. To demonstrate the 2D imaging capability of this technique, geometrically structured samples with varying composition were prepared by pulsed laser deposition (PLD) and ion beam etching procedures. These thin films with a thickness of 220 nm were spatially resolved analysed. As a result, 2D intensity maps obtained by online-LASIL can be reported for the first time. Additionally a new approach for simultaneous online quantification was developed by adopting the standard addition concept allowing to correct for instrumental drifts of long time measurements.

Quantitation of copper chlorophylls in green table olives by ultra-high-performance liquid chromatography with inductively coupled plasma isotope dilution mass spectrometry

Table olives, a widely consumed delicacy, are often selected by consumers based on the shade of their green color. The appealing coloration of fresh olives fades to brown or pale yellow during the industrial processing necessary for commercialization and storage, as a result of the degradation of chlorophyll a and b to their corresponding pheophytins and other chlorophyll degradation products (CDP). The re-greening of table olives may be achieved by complexation of CDP with Cu2+, to form stable bright green copper CDP (Cu-CDP) complexes. To study this phenomenon, we developed a novel method to separately extract lipophilic and hydrophilic Cu-CDP and quantify Cu-CDP by UHPLC combined with inductively coupled plasma isotope dilution mass spectrometry (UHPLC-ICP-ID-MS) using post-column isotopic dilution with 65Cu. This technique does not require species-specific calibration standards and was applied to survey the Cu-CDP composition of the various types of table olives sold in the US market. The CDP and Cu-CDP extracted from table olives were identified by high resolution full-scan mass spectrometry. Total elemental Cu in table olives was measured by microwave digestion followed by ICP-MS detection and correlated with the content of Cu-CDP. Pale yellow olives contained <1 mg/kg lipophilic Cu-CDP and <3.5 mg/kg total elemental Cu. Bright green table olives contained 4–22 mg/kg lipophilic Cu-CDP and 14.4–161 mg/kg total elemental Cu in contrast to <6 mg/kg reported for natural abundance, indicating the formation of Cu-CDP was achieved by addition of copper salts. A dark green sample with 2.5 mg/kg of total copper and 0.267 mg/kg lipophilic Cu-CDP may have been processed by addition of sodium copper chlorophyllin (SCC); the higher content of Cu isochlorin e4 compared to Cu 152-Me-chlorin e6 supports this conclusion.

Exploring the upper particle size limit for field flow fractionation online with ICP-MS to address the challenges of water samples from the Taihu Lake

Regular algal blooms are occurring in Taihu lake, which may be triggered by resuspension of sediments containing relevant amounts of phosphorus. Therefore, our study aims at quantification of phosphorus concentrations bound to suspended particulate matter in Taihu water samples to investigate this hypothesis. A field flow fractionation (FFF) method online with ICP-MS detection was developed to achieve an overview on particulate fractions of phosphorus and related elements including Fe, Al and C from the low nanometer to the low micrometer size range. Mass balance of dissolved and particulate elemental contents was established for quality control purpose and indicated low recovery of Fe, Al and P. Complementary determination of volume based particle size distribution by dynamic imaging analysis showed a majority of particle volume and thus mass in particles with size >5 μm. In order to address this challenge, the upper particle size limit of FFF online with ICP-MS was for the first time investigated in detail using well characterised monodisperse latex particles as model for organic matter in the low micrometer size range including microalgae. The effect of pre-filtration of the sample as well as the contribution of sample introduction via three different interfaces including micromist nebuliser/spray chamber, direct injection nebulisation and APEX with heated spray chamber and solvent removal by condensation on the particulate carbon recovery was studied by ICP-MS detection. The same instrumental setup was also applied for the characterisation of particulate elemental contents in the Taihu water samples as far as possible. Significant improvement of the detected particulate fraction in Taihu water samples was achieved by increasing the membrane pore size for pre-filtration and by using the APEX for introduction of the eluate from FFF into ICP-MS.

Application of new covalently-bound diglycolamide sorbent in sequential injection analysis flow system for sample pretreatment in ICP-MS determination of 239Pu at ppt level

Diglycolamide ligands are widely applied in the analysis of radionuclides, especially lanthanides and actinides. They are used in liquid-liquid extraction procedures or in solid-phase extraction sorbents where they are adsorbed on the surface of hydrophobic polymers.The main objective of this study was to synthesize the N,N,N'N′-tetrahexyl diglycolamide with one vinyl terminating group (vTHDGA) for further covalent immobilization on the polystyrene-divinylbenzene polymeric support. The obtained complexing resin (THDGA) was employed for the mechanized sample pretreatment in the Sequential Injection Analysis - Lab-on-Valve (SIA-LOV) flow system for the determination of 239Pu using ICP-MS detection. The analytical procedure was optimized in terms of selectivity towards several other radionuclides and elements forming potentially isobaric interferences in mass spectrometry. For 100 mL volume of sample to be analyzed, the method detection limit (MDL) was 96 mBq L−1 (42 pg L−1). The developed method was employed for the determination of 239Pu in real samples of a nuclear reactor coolant and spent fuel pool water from a nuclear reactor.