Coupled Plasma Mass Spectrometric Detection Research Articles

Quantitative Profiling of in Vivo Generated Cisplatin−DNA Adducts Using Different Isotope Dilution Strategies

Platinum compounds are the major group of metal-based chemotherapeutic drug used in current practice and still a topic of intense investigation. The relative contribution of structurally defined cisplatin adducts with DNA to induce apoptosis and the cellular processing of these lesions is still poorly understood mostly due to the lack of sensitive and accurate analytical tools for in vivo studies. In this regard, two novel sensitive and selective strategies are proposed here to quantify cisplatin-DNA adducts generated in Drosophila melanogaster larvae and in head and neck squamous cell carcinoma cultures. The methods involve the isolation and enzymatic digestion of the DNA in the samples exposed to cisplatin and further quantification by high-performance liquid chromatography with inductively coupled plasma mass spectrometric detection (HPLC-ICPMS). Two different strategies, based on isotope dilution analysis (IDA), have been attempted and evaluated for quantification: species-unspecific (the postcolumn addition of a 194Pt-enriched solution) and the species-specific (by means of a synthesized isotopically enriched cisplatin (194Pt) adduct). For the second approach, the synthesis and characterization of the cisplatin adduct in a custom oligonucleotide containing the sequence (5'-TCCGGTCC-3') was necessary. The adducted oligo was then added to the DNA samples either before or after enzymatic hydrolysis. The results obtained using these two strategies (mixing before and after enzymatic treatment) permit to address, quantitatively, the column recoveries as well as the efficiency of the enzymatic hydrolysis. Species-specific spiking before enzymatic digestion provided accurate and precise analytical results to clearly differentiate between Drosophila samples and carcinoma cell cultures exposed to different cisplatin concentrations.

Multiplexed Determination of Protein Biomarkers Using Metal-Tagged Antibodies and Size Exclusion Chromatography−Inductively Coupled Plasma Mass Spectrometry

A liquid-phase immunoassay was developed for the simultaneous determination of five cancer biomarker proteins: alpha-fetoprotein (AFP), human chorionic gonadotropin (hCG), carcinoembryonic antigen (CEA), ovarian tumor antigen (CA125/MUC16), and gastrointestinal tumor antigen (CA19-9). The method was based on the incubation of a serum (or tissue cytosol) with five antibodies, each labeled with a different lanthanide (Pr(3+), Eu(3+), Gd(3+), Ho(3+), and Tb(3+), respectively) followed by the specific determination of the immunocomplex formed by size exclusion chromatography with inductively coupled plasma mass spectrometric detection (SEC-ICPMS). The sensitivity of the method was comparable with that attainable by enzyme-linked immunosorbent assay (ELISA) or radioimmunoassay with the advantages of multiplexed analysis capacity, virtually no sample preparation, and sample amount consumption, ca. 3 times lower than an ELISA test. The method was validated for the analysis of the proteins in human serum and proved to be able to discriminate ovary and uterus tumor tissue samples from those of healthy subjects.

Liquid chromatography with complementary electrospray and inductively coupled plasma mass spectrometric detection of ferrocene-labelled peptides and proteins

Succinimidylferrocenyl propionate (SFP) is introduced as labelling agent for amino functions in peptides and proteins. The resulting derivatives are characterised by considerably lower polarity compared with the native analytes and can thus be well separated by means of reversed phase liquid chromatography (RP-LC). The reaction products are characterised by electrospray ionisation mass spectrometry (ESI-MS) and inductively coupled plasma mass spectrometry (ICP-MS). A further advantage of the method is a simple and straightforward derivatisation protocol. Different basic and acidic model proteins as lysozyme, beta-lactoglobulin A and insulin were derivatised using SFP. Furthermore, the first dual-labelling strategy of thiol and amino groups with ferrocene-based reagents is presented. Whereas the amino groups were derivatised with SFP, the thiol groups were functionalised by reaction with ferrocenecarboxylic acid(2-maleimidoyl)ethylamide. Again, LC/ESI-MS is a suitable tool to characterise the modified peptides and proteins.

Simultaneous determination of inorganic and organic antimony species by using anion exchange phases for HPLC–ICP-MS and their application to plant extracts of Pteris vittata

Antimony is a common contaminant at abandoned sites for non-ferrous ore mining and processing. Because of the possible risk of antimony by transfer to plants growing on contaminated sites, it is of importance to analyze antimony and its species in such biota. A method based on high performance liquid chromatographic separation and inductively coupled plasma mass spectrometric detection (HPLC–ICP-MS) was developed to determine inorganic antimony species such as Sb(III) and Sb(V) as well as possible antimony-organic metabolisation products of the antimony transferred into plant material within one chromatographic run. The separation is performed using anion chromatography on a strong anion exchange column (IonPac AS15/AG 15). Based on isocratic optimizations for the separation of Sb(III) and Sb(V) as well as Sb(V) and trimenthylated Sb(V) (TMSb(V)), a chromatographic method with an eluent gradient was developed. The suggested analytical method was applied to aqueous extracts of Chinese break fern Pteris vittata samples. The transfer of antimony from spiked soil composites into the fern, which is known as a hyperaccumulator for arsenic, was investigated under greenhouse conditions. Remarkable amounts of antimony were transferred into roots and leaves of P. vittata growing on spiked soil composites. Generally, P. vittata accumulates not only arsenic (as shown in a multiplicity of studies in the last decade), but also antimony to a lower extent. The main contaminant in the extracts was Sb(V), but also elevated concentrations of Sb(III) and TMSb(V) (all in μg L −1 range). An unidentified Sb compound in the plant extracts was detected, which slightly differ in elution time from TMSb(V).

Arsenic speciation in rice, straw, soil, hair and nails samples from the arsenic-affected areas of Middle and Lower Ganga plain

In the present study, pressurised liquid extraction and ultrasound probe sonication, for the latter in combination with a mixed enzymatic treatment in case of rice and straw samples, were applied as sample preparation prior to arsenic speciation analysis by high pressure liquid chromatography coupled to inductively coupled plasma mass spectrometric detection (HPLC-ICP-MS). A significant number of samples as different as rice, straw, soil, nail and hair, all coming from the heavily arsenic-contaminated Middle and Lower Ganga plain area, could be investigated with validated methods, supported by high speed extraction methods. For rice and paddy samples, inorganic arsenic counted up to 70–98% of the total arsenic content, being the major species As (III). The levels of arsenic obtained from straw and soil samples are significantly higher than the background levels, being the major species As (V), thus increasing human exposure to arsenic via the soil-plant-animal-human pathway. Concentrations found in hair and nails were significantly higher than their background levels: 39- and 20-fold for hair and nails, respectively. These samples contained mainly inorganic arsenic in its tri- and pentavalent forms. Results indicate that, under the local frame conditions, arsenic mainly enters into the food chain via its more problematic inorganic forms. Arsenic speciation analysis proves to be a powerful tool for a complete analytical assessment in epidemiological studies covering the endemic areas.

A study of Se-Hg antagonism in Glycine max (soybean) roots by size exclusion and reversed phase HPLC–ICPMS

An attempt was made to study selenium (Se) and mercury (Hg) interactions in plants, specifically soybean (Glycine max), by inductively coupled plasma mass spectrometric detection. Greenhouse-cultivated plants were subjected to treatment with different regimens of Se and Hg and analyzed for their metabolized species in roots, stems, leaves, pods and beans. Most of the water-soluble Hg was found to be localized in the roots in association with Se in a high molecular weight entity, as identified by size exclusion chromatography. This entity was also extracted in protein specific isolate, but it resisted enzymatic breakdown. Complete breakdown of this high molecular weight species was accomplished by acid hydrolysis. Optimization of the conditions for acid hydrolysis is discussed. Hg and Se species found in root extract were studied by ion-pairing chromatography. In a sub-study, the Se distribution pattern was found to be unaffected by the presence of Hg, but the amount of Se assimilated was found to be higher in plants coexposed to Hg.

Speciation of Al in human serum by convective-interaction media fast-monolithic chromatography with inductively coupled plasma mass spectrometric detection

A new analytical procedure using anion-exchange separation support based on convective-interaction media (CIM) was developed for the speciation of Al in human serum. The separation of proteins was performed on a weak anion-exchange CIM diethylamine (DEAE) fast-monolithic disk. To prevent co-elution of low molecular mass (LMM) Al species with high molecular mass (HMM) Al compounds on CIM disk serum proteins were first separated from LMM-Al species by the use of size exclusion chromatography (SEC). For this purpose 1 mL of serum was injected onto SEC (Superdex 75 HR 10/30) column. Isocratic elution using 0.05 M TRIS–HCl + 0.03 M NaHCO 3 was applied and separation of proteins was followed by UV detection at 278 nm. It was experimentally proven that proteins were eluted in 5.5 mL peak that was collected into a polyethylene cup. A 0.1 mL of the sample aliquot was then injected onto the CIM DEAE disk. The separation of serum proteins was obtained in 10 min by applying linear gradient elution from 100% buffer A (0.05 M TRIS–HCl + 0.03 M NaHCO 3) to 100% buffer B (A + 1 M NH 4Cl) and followed by UV detection at 278 nm. Separated Al species were detected on-line by inductively coupled plasma mass spectrometry (ICP-MS). Well-resolved protein peaks were obtained. It was experimentally proven that 90 ± 3% of Al in spiked serum of renal patient was eluted under the transferrin peak. The proposed speciation procedure removes LMM-Al species and enables reliable determination of the concentration and composition of Al bound to proteins by CIM DEAE-ICP-MS when the concentration of Al in serum is higher than 5 ng mL −1. In comparison to chromatographic columns CIM disks enable faster separation and simpler manipulation during cleaning procedure and coupling to ICP-MS.

An accurate and sensitive method for the determination of methylmercury in biological specimens using GC-ICP-MS with solid phase microextraction

A highly sensitive and selective method has been developed for the determination of methylmercury in biological specimens and NIST Standard Reference Materials (SRMs). The procedure involves microwave extraction with acetic acid, followed by derivatization and headspace solid-phase microextraction (SPME) with a polydimethylsiloxane (PDMS)-coated silica fiber. Optimization of conditions including gas chromatograph injection temperature, microwave extraction power and microwave extraction time are presented. The identification and quantification (via the method of standard additions) of the extracted compounds is carried out by capillary gas chromatography with inductively coupled plasma mass spectrometric detection (GC-ICP-MS) using a unique heated interface that was designed for this work. The SPME-GC-ICP-MS method was validated for the determination of methylmercury (MeHg) concentrations in a variety of biological Standard Reference Materials (SRMs), ranging from 13.2 ng g−1 in SRM 1566b Oyster Tissue, to 397 ng g−1 in SRM 1946 Lake Superior Fish Tissue. Additionally, this method was applied to the determination of MeHg in seabird eggs (common murres, Uria aalge and thick-billed murres, Uria lomvia) collected from colonies on Little Diomede and Bogoslof islands in the Bering Sea and Saint Lazaria Island in the Gulf of Alaska and cryogenically banked in the Marine Environmental Specimen Bank. The results obtained demonstrate that SPME-GC-ICP-MS is a sensitive technique for the determination of methylmercury at trace and ultra-trace levels in a variety of natural matrices with high reproducibility and accuracy. In all instances, the sample-to-sample variability was typically 2% relative standard deviation (RSD) and the method detection limit for methylmercury was 4.2 pg g−1 (as Hg), based on a 0.5 g tissue sample of SRM 1566b Oyster Tissue.

Speciation analysis for mercury in gas condensates by capillary gas chromatography with inductively coupled plasma mass spectrometric detection

A method allowing species-selective determination of atomic mercury, non-polar dialkylated mercury compounds, polar monoalkylated species and inorganic mercury complexes in natural gas condensates was developed. Inductively coupled plasma mass spectrometry was employed as a detection method for capillary gas chromatography and compared with microwave induced plasma atomic emission detection for the analysis of hydrocarbon-rich matrices. The method was based on two consecutive injections allowing comprehensive speciation analysis. First a sample aliquot was diluted with toluene and analysed for Hg 0 and individual dialkylmercury compounds. Then, another aliquot was butylated with a Grignard reagent for the species specific determination of Hg(II) and monoalkylated mercury species. The detection limits were down to 0.08 pg level.

EVALUATION OF HPLC SYSTEMS FOR THE SEPARATION AND QUANTIFICATION OF ARSENIC COMPOUNDS FROM APPLE EXTRACTS

Several different high performance liquid chromatography (HPLC) systems were evaluated for the applicability for the determination of trace level arsenic compounds from extracts of freeze-dried apple samples. Various gradients using ion-pair reversed-phase HPLC were explored. Gradient anion-exchange HPLC, as well as a simple isocratic system, were also evaluated in this study. Two extraction procedures were used. Simple sonication by a common laboratory ultrasonic cleaner using a 50/50 (v/v) water/methanol solvent mixture and a two step procedure using initial overnight treatment with α-amylase enzyme followed by sonication with a 60/40 (v/v) acetonitrile/water solvent mixture were evaluated. Inductively Coupled Plasma-Mass Spectrometric (ICP-MS) detection was used to measure the arsenic compounds contained within the apple extracts. The three most abundant arsenic compounds found in the extracts were arsenite (As III), arsenate (As V) and dimethylarsinic acid (DMAA).

Bioavailability of cadmium and lead in cocoa: comparison of extraction procedures prior to size-exclusion fast-flow liquid chromatography with inductively coupled plasma mass spectrometric detection (SEC-ICP-MS)

Download options Please wait... Article information DOI https://doi.org/10.1039/B201639G Article type Paper Submitted 13 Feb 2002 Accepted 21 May 2002 First published 14 Jun 2002 Download Citation J. Anal. At. Spectrom., 2002,17, 880-886 BibTex EndNote MEDLINE ProCite ReferenceManager RefWorks RIS Permissions Request permissions Bioavailability of cadmium and lead in cocoa: comparison of extraction procedures prior to size-exclusion fast-flow liquid chromatography with inductively coupled plasma mass spectrometric detection (SEC-ICP-MS) S. Mounicou, J. Szpunar, R. Lobinski, D. Andrey and C. Blake, J. Anal. At. Spectrom., 2002, 17, 880 DOI: 10.1039/B201639G To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page. If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given. If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page. Read more about how to correctly acknowledge RSC content. Social activity Tweet Share Search articles by author Sandra Mounicou Joanna Szpunar Ryszard Lobinski Daniel Andrey Christopher-John Blake

Development and application of a method for the analysis of brominated flame retardants by fast gas chromatography with inductively coupled plasma mass spectrometric detection

Download options Please wait... Article information DOI https://doi.org/10.1039/B207521K Article type Paper Submitted 01 Aug 2002 Accepted 12 Sep 2002 First published 30 Sep 2002 Download Citation J. Anal. At. Spectrom., 2002,17, 1480-1485 BibTex EndNote MEDLINE ProCite ReferenceManager RefWorks RIS Permissions Request permissions Development and application of a method for the analysis of brominated flame retardants by fast gas chromatography with inductively coupled plasma mass spectrometric detection A. P. Vonderheide, M. Montes-Bayón and J. A. Caruso, J. Anal. At. Spectrom., 2002, 17, 1480 DOI: 10.1039/B207521K To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page. If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given. If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page. Read more about how to correctly acknowledge RSC content. Social activity Tweet Share Search articles by author Anne P. Vonderheide Maria Montes-Bayón Joseph A. Caruso

Solid-phase microextraction as a sample preparation strategy for the analysis of seleno amino acids by gas chromatography-inductively coupled plasma mass spectrometry.

Solid-phase microextraction (SPME) is used as a sample preparation strategy for gas chromatographic (GC) analysis of the seleno amino acids, selenomethionine (SeMet), selenoethionine (SeEt) and selenocystine (SeCys). Acylation of the amino group and esterification of the carboxylic group in these compounds was performed with isobutylchloroformate to increase volatility. The amino acid derivatives were then extracted by silica fibers with polydimethylsiloxane (PDMS) coatings prepared by the sol-gel process. Investigations of extraction time, acid and salt addition, and polymer length (for the sol-gel process) were conducted with the goal of procedural optimization. Initial characterizations were conducted using gas chromatography with flame ionization detection (GC-FID). Inductively coupled plasma mass spectrometric detection was employed for final selenium detection. Sub-ppb detection limits were obtained for all analytes although relative standard deviations were higher than those typically obtained in solid-phase microextraction.

Analysis of selenized yeast for selenium speciation by size-exclusion chromatography and capillary zone electrophoresis with inductively coupled plasma mass spectrometric detection (SEC-CZE-ICP-MS)

A two-dimensional separation approach based on size-exclusion chromatography (SEC) followed by capillary zone electrophoresis (CZE) is proposed for the mapping of seleno-compounds in aqueous extracts of selenized yeast. The coupling of CZE with ICP-MS via a self-aspirating total consumption micronebulizer was optimized for the separation of Se species. Selenate, selenite, selenocystine, selenomethionine and selenoethionine could be baseline separated at pH 10.5 using a 10 mM phosphate buffer containing 0.8 mM cetyltriammonium bromide. Detection limits were 7–18 ng mL−1 for a 20 nL injection. The CZE-ICP-MS analysis of a yeast extract demonstrated the presence of many Se species, which all migrated less rapidly than any of the standards. The following difficulties occurred during the CZE-ICP-MS analysis of the SEC fractions of the extract: the recovery of the high-molecular Se-species from the electrophoretic capillary, the presence of a large number of compounds in the medium-molecular weight fraction and the presence of a single intense peak for the low-molecular weight fraction. Proteolysis of the high- and medium-molecular weight fractions dramatically improved the recovery of Se species from the capillary, resulting in several peaks in the CZE-ICP-MS electropherograms.

Metallothionein isoforms separation and cadmium speciation by capillary electrophoresis with ultraviolet and quadrupole-inductively coupled plasma mass spectrometric detection

A complete characterisation of metallothioneins (MTs) in biological systems requires first an optimal separation of the different isoforms and sub-isoforms present. A method for the adequate separation of rabbit liver MT1 and MT2 mixtures by capillary zone electrophoresis (CZE) with UV detection is developed here. Different experimental conditions affecting both, peak shape and resolution achieved, are investigated in detail. Thus, the influence of the composition, ionic strength and pH of the buffer solution, and the separation voltage, have been studied. In order to improve the resolution between sub-isoforms, the electroosmotic flow has been also changed and its effect investigated by adding organic modifiers. Analytical performance characteristics are evaluated: calibration graphs were linear between 70 and 205 μg ml −1 for MT1 and between 83 and 242 μg ml −1 for MT2, while the detection limits were 4 and 3 μg ml −1, respectively. Speciation of the metal–MTs compounds has been accomplished by the coupling CZE–ICP–MS by means of different nebulisers: a conventional concentric Meinhard nebuliser, a Babington type one and a high efficiency nebuliser (HEN). Finally, real sample MTs analyses have been carried out in mussel hepatopancreas cytosols, previously exposed to a metal enriched environment.

HG/LT-GC/ICP-MS coupling for identification of metal(loid) species in human urine after fish consumption.

Human urine samples after fish consumption have been investigated by low-temperature gas chromatography with inductively coupled plasma mass spectrometric detection after sample derivatization by hydride generation (HG/LT-GC/ICP-MS). This analytical technique enabled the identification of organometal(loid) compounds in human urine; species of the six elements germanium, arsenic, selenium, tin, antimony, and mercury were determined. Three different organic selenium species, two germanium species, seven arsenic species, four tin species, five antimony species, and one species of mercury were found; 18 of the 22 species detected could be identified. The relative detection limits ranged between 2 and 12 pg x L(-1) (x=element). These organometal(loid) compounds probably build up in the human body under the influence of micro-organisms, in the presence of hydrogen sulfide and methane, in the human intestine.

Uptake of arsenite and arsenate by clinoptilolite-rich tuffs

Clinoptilolite-containing rocks were used to study the possible uptake of arsenite (H 3AsO 3) and arsenate (H 2AsO 4 −) species from aqueous solution. Two samples also exhibited mordenite and erionite zeolitic phases. Batch and isotherm studies at pH 4 in the concentration range 0.1<C< 4 mg l −1 were performed. The experimental data were used to model Freundlich, Langmuir and Langmuir–Freundlich adsorption isotherms. Solutions were analyzed by means of ion chromatography coupled with inductively coupled plasma mass spectrometric detection (IC-ICP-MS). All zeolitic samples investigated removed more H 2AsO 4 − than H 3AsO 3 at equivalent arsenic concentrations. Although the saturation capacity of the tuffs studied was inversely related to the silicium dioxide content and directly to the iron content in the acid-washed zeolite, the addition of iron did not significantly improve the removal efficiency. Up to 98% of H 3AsO 3 were removed from a 500 μg As l −1 solution by three of the samples studied after a contact time of 70 days.

Comparison of metal pre-concentration on immobilized Kelex-100 and quadruple inductively coupled plasma mass spectrometric detection with direct double focusing inductively coupled plasma mass spectrometric measurements for ultratrace multi-element determinations in sea-water

The extraction/pre-concentration capabilities of the liquid ion exchanger 7-(4-ethyl-1-methyloctyl)-8-hydroxyquinoline (Kelex-100) immobilized on octadecyl silica have been evaluated for the analysis of trace metals in sea-water by quadruple ICP–MS (ICP–QMS) and the results are compared with those directly obtained by double focusing ICP–MS (ICP–SMS), after a simple 1+4 dilution of the sea-water sample. The retention capabilities of the different materials (Kelex-100 retained on Amberlite XAD-7 and Bondapack C-18 (BC-18)) were evaluated by using copper as test element and ICP–QMS for detection. Kelex-100 supported onto BC-18 provided the best performance and was evaluated, both on-line and off-line, for the pre-concentration of different trace elements present in sea-water. Using the selected “off-line” procedure, satisfactory recoveries (95–104%) and adequate detection limits in the ng l −1 range (V, 10; Ni, 30; Mn, 70; Cu, 170; Zn, 150; Cd, 7; Pb, 10 and U, 1 ng l −1) were obtained. Such multi-elemental trace metal determinations in sea-water were also attempted directly, after a simple 1+4 dilution of the sample and calibration with internal standards (IS) using different mass resolutions to avoid polyatomic interferences when necessary. The analytical performance characteristics and limitations of both approaches for multi-elemental determinations in coastal sea-water are compared.

Determination and Speciation of Aluminum in Environmental Samples by Cation Exchange High-Performance Liquid Chromatography with High Resolution ICP-MS Detection

A cation-exchange high-performance liquid chromatography with high resolution inductively coupled plasma mass spectrometric detection (CE-HPLC/ICP-MS) was developed for the determination and the speciation of aluminum in environmental samples. Three types of aluminum species (Al3+) were separated from one another, and were determined with the present system. The comparison of the present system with an established CE-HPLC with fluorimetric detection using 5-sulfo-8-quinolinol (CE-HPLC/FL) was described. The present system showed better sensitivity for aluminum than CE-HPLC/FL. Moreover, the analytical results for soil extract and lake water samples obtained with both methods were in good agreement with each other.

Separation of metalloporphyrins by capillary electrophoresis with UV detection and inductively coupled plasma mass spectrometric detection

Vitamin B 12, cobalt protoporphyrin, manganese protoporphyrin, and zinc protoporphyrin were separated using capillary electrophoresis, and a comparison was made between detection with inductively coupled plasma mass spectrometry (ICP-MS) and UV detection. Absolute limits of detection were slightly better with ICP-MS detection than with UV detection, but for both methods absolute detection limits were in the picogram range. The migration times of the analytes decreased by several minutes when ICP MS detection was employed, and this phenomenon was believed to be a result of a “suction effect” that developed when the CE capillary was interfaced to the ICP-MS nebulizer. However, the resolution between species containing the same metal atom was not altered significantly, and the separation was completed in much less time relative to separations performed with UV detection.