Screening for selected toxic elements in urine by sequential-scanning inductively-coupled plasma atomic emission spectrometry

A rapid screening method for nine elements (Se, As, Cr, Zn, Cd, Pb, Ni, Mn, and Cu) in human urine is described. A sequential-scanning inductively-coupled plasma atomic emission spectrometer, incorporating a cross-flow nebulizer, was used. Internal standardization with yttrium compensated for the differences between the aqueous calibration standards and the undiluted urine specimens. Accuracy was evaluated with aqueous (NBS SRM 1643a, EPA 378-13, and EPA 476-3) and urine (NBS SRM 2670 and Fisher Urichem Level II) reference and control materials. Detection limits for the system were evaluated from analyses of normal urine materials found to contain low levels of the elements investigated.     

The extraction, determination and speciation of tributyltin in seawater

Summary Methods have been developed for the determination, by carbon-furnace atomisation atomic absorption spectrophotometry, of inorganic and of total butyltin in seawater. Concentration/separations are based on the solvent extraction of organotin species directly into toluene and of inorganic tin as its tin(IV) 8-hydroxyquinoline chelate into chloroform. Detection limits are 0.7–0.8 ng.

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Extraktion, Bestimmung und Speziation von Tributylzinn in Seewasser

     

GC FPD method for the simultaneous speciation of butyltin and phenyltin compounds in waters

A method is described for the simultaneous determination of nanogram amounts of mono-, di- and tri-butyltin compounds in water. The procedure is based on the conversion of tin compounds to volatile species by Grignard pentylation and analysis using GC with flame photometric detection (GC FPD). The ionic compounds are extracted from diluted acidified (HBr) aqueous solutions by using a pentane-tropolone solution. The extracted organotin compounds are pentylated by a Grignard reagent and purified on a Fluorisil column before analysis by GC FPD. The detection limits are 20 ng dm^?3 for butyltin compounds and 50 ng dm^?3 for phenyltin compounds. Recoveries from spiking experiments in tap-water and natural seawater matrices, in which no organotin compounds were detected, were greater than 90% for most of the alkyltin compounds.     

Comparative study on conventional and low-flow nebulizers for arsenic speciation by means of microbore liquid chromatography with inductively coupled plasma mass spectrometry

The performance of conventional and low-flow nebulizer systems with liquid chromatography in differentiating four arsenic species in urine was evaluated. Two low-flow (DIN and MCN) chamber assemblies and a conventional (CFN) nebulizer-spray chamber assembly were compared in the hyphenation of anion-exchange microbore liquid chromatography with inductively coupled plasma mass spectrometry. Under optimal analytical conditions, the detection limits of the four arsenic species were 0.2-0.6 ng ml(-1) for all the nebulizer systems tested. The chromatographic resolution was best in the case of DIN due to its minimal off-column dead volume and superior transport efficiency. Four arsenic species were determined in the certified reference materials NIST SRM 2670E and 2670N.     

Determination of seven arsenic compounds in urine by HPLC-ICP-DRC-MS: a CDC population biomonitoring method

A robust analytical method has been developed and validated by use of high-performance liquid chromatography inductively coupled plasma mass spectrometry with Dynamic Reaction Cell? (DRC) technology that separates seven arsenic (As) species in human urine: arsenobetaine (AB), arsenocholine, trimethylarsine oxide (TMAO), arsenate (As(V)), arsenite (As(III)), monomethylarsonate, and dimethylarsinate. A polymeric anion-exchange (Hamilton PRP® X-100) column was used for separation of the species that were detected at m/z 75 by ICP-DRC-MS (PerkinElmer? SCIEX® ELAN DRCII?) using 10% hydrogen–90% argon as the DRC gas. The internal standard (As) is added postcolumn via an external injector with a sample loop. All analyte peaks were baseline-separated except AB and TMAO. Analytical method limits of detection for the various species ranged from 0.4 to 1.7 μg L^?1 as elemental As. As(III) conversion to As(V) was avoided by adjusting the urine sample to 相似文献   

Direct determination of normal physiological concentrations of major,minor and trace elements in undiluted microlitre volumes of human body fluids by discrete nebulization and atomic emission spectrometry with a nitrous oxide/acetylene flame

The concentrations of major (Na, K, Ca, Mg), minor (Cu, Fe) and trace (Li, Sr, Ba) elements in untreated, undiluted human body fluids (serum, urine, saliva, cerebrospinal fiuid) are determined. The sample volume is 110 μl. Micro-standard addition procedures and manual background correction are used to minimize matrix interferences. The RSD ranged from 3.1. to 8.6%. Accuracy was evaluated with NIES Candidate Reference Material freeze-dried human serum and NBS SRM-2670 freeze-dried urine.     

Speciation of butyltin compounds in marine sediments by preconcentration on C60 and gas chromatography-mass spectrometry

A new method for the speciation of butyltin compounds by solid phase extraction and direct injection using gas chromatography-mass spectrometry (GC/MS) is described. The compounds were complexed with sodium diethyldithiocarbamate and retained on a C60 sorbent column. The neutral chelates of butyltin compounds were eluted with ethyl acetate containing NaBPr4 as derivatising reagent. The main analytical figures of merit of the proposed method for 10 ml of sample are: linear range 0.2-35 ng/g expressed as Sn; limits of detection, 0.07, 0.09 and 0.10 ng/g as Sn for monobutyltin, dibutyltin and tributyltin, respectively. No interferences from metal ions such as Zn2+, Fe3+, Sb3t, Pb2+, Ni2+ and Mn2+ were observed in the determination of organotin compounds. The validation of method was performed out by the analysis of a standard reference sediment (CRM 462). The method was also applied to the determination of butyltin compounds in marine sediment samples.     

Development and application of an ultratrace method for speciation of organotin compounds in cryogenically archived and homogenized biological materials

An accurate, ultra-sensitive and robust method for speciation of mono, di, and tributyltin (MBT, DBT, and TBT) by speciated isotope-dilution gas chromatography-inductively coupled plasma-mass spectrometry (SID-GC-ICPMS) has been developed for quantification of butyltin concentrations in cryogenic biological materials maintained in an uninterrupted cryo-chain from storage conditions through homogenization and bottling. The method significantly reduces the detection limits, to the low pg g(-1) level (as Sn), and was validated by using the European reference material (ERM) CE477, mussel tissue, produced by the Institute for Reference Materials and Measurements. It was applied to three different cryogenic biological materials-a fresh-frozen mussel tissue (SRM 1974b) together with complex materials, a protein-rich material (whale liver control material, QC03LH03), and a lipid-rich material (whale blubber, SRM 1945) containing up to 72% lipids. The commutability between frozen and freeze-dried materials with regard to spike equilibration/interaction, extraction efficiency, and the absence of detectable transformations was carefully investigated by applying complementary methods and by varying extraction conditions and spiking strategies. The inter-method results enabled assignment of reference concentrations of butyltins in cryogenic SRMs and control materials for the first time. The reference concentrations of MBT, DBT, and TBT in SRM 1974b were 0.92 +/- 0.06, 2.7 +/- 0.4, and 6.58 +/- 0.19 ng g(-1) as Sn (wet-mass), respectively; in SRM 1945 they were 0.38 +/- 0.06, 1.19 +/- 0.26, and 3.55 +/- 0.44 ng g(-1), respectively, as Sn (wet-mass). In QC03LH03, DBT and TBT concentrations were 30.0 +/- 2.7 and 2.26 +/- 0.38 ng g(-1) as Sn (wet-mass). The concentration range of butyltins in these materials is one to three orders of magnitude lower than in ERM CE477. This study demonstrated that cryogenically processed and stored biological materials are a promising alternative to conventional freeze-dried materials for organotin speciation analysis, because these are, at present, the best conditions for minimizing degradation of thermolabile species and for long-term archival. Finally, the potential of the analytical method was illustrated by analysis of polar bear (Ursus maritimus) and beluga whale (Delphinapterus leuca) liver samples that had been collected in the Arctic and archived at the Marine Environmental Specimen Bank. Significant concentrations of butyltin compounds were found in the samples and provide the first evidence of the presence of this class of contaminant in the Arctic marine ecosystem. Figure Eye catch image.     

Determination of paraquat and diquat in human body fluids by high-performance liquid chromatography/tandem mass spectrometry

Paraquat (PQ) and diquat (DQ) in human whole blood and urine were analyzed by high-performance liquid chromatography/tandem mass spectrometry (HPLC/MS/MS) with positive ion electrospray ionization (ESI). The compounds were extracted with Sep-Pak C18 cartridges from whole blood and urine samples containing ethyl paraquat as an internal standard. The separation of PQ and DQ was carried out using ion-pair chromatography with heptafluorobutyric acid in 20 mM ammonium acetate and acetonitrile gradient elution for successful coupling with MS. Both compounds formed base peaks due to [M-H]+ ions by HPLC/ESI-MS and the product ions produced from each [M-H]+ ion by HPLC/MS/MS. Selective reaction monitoring (SRM) showed much higher sensitivity for both body fluids. Therefore, a detailed procedure for the detection of compounds by SRM with HPLC/MS/MS was established and carefully validated. The recoveries of PQ and DQ were 80.8-95.4% for whole blood and 84.2-96.7% for urine. The calibration curves for PQ and DQ showed excellent linearity in the range of 25-400 ng ml(-1) of whole blood and urine. The detection limits were 10 ng ml(-1) for PQ and 5 ng ml(-1) for DQ in both body fluids. The intra- and inter-day precision for both compounds in whole blood and urine samples were not greater than 13.0%. The data obtained from the determination of PQ and DQ in rat blood after oral administration of the compounds are also presented.     

Determination of beryllium and selenium in human urine and of selenium in human serum by graphite-furnace atomic absorption spectrophotometry.

For human urine beryllium (Be), each sample (500 microl) was diluted (1+1) with Nash reagent (containing 0.2% (v/v) acetylacetone and 2.0 M ammonium acetate buffer at pH 6.0) and then a 20-microl volume of Triton X-100 (0.4%, v/v) aqueous solution was added. An aliquot (10 microl) of the diluted urine mixture was introduced into a graphite cuvette and was atomized according to a temperature program. The method detection limit (MDL, 3sigma) for Be was 0.37 microg/l in the undiluted urine sample and the calibration graph was linear up to 65.0 microg/l. Calibration graphs were prepared by the standard addition method. Accuracies of 98.6-102% were obtained when testing standard reference material (SRM 2670) freeze dried human urine samples. Precision (relative standard deviation, RSD) for urine Be was < or = 2.3% (withinrun, n = 5) and was < or = 3.0% (between-run, n = 3). For human urine and serum selenium (Se), samples (100 microl) were diluted with HNO3 (0.2%, v/v) to make a (1+1) dilution for urine analysis or a (1+4) dilution for serum analysis. An additional aliquot (10 microl) of Triton X-100 (0.1%, v/v) was added to each 200 microl of (1+1) diluted urine (or 20 microl of the Triton X-100 was added to each 500 microl of (1+4) diluted serum) sample. After the diluted sample mixture (10 microl) was introduced into a graphite cuvette, the corresponding chemical modifier (10 microl, containing Ni2+ + Pd + NH4NO3 in HNO3 (0.2%, v/v)) was added to it and the mixture was atomized. The MDL (3sigma) for Se in urine and in serum was 4.4 and 21.4 microg/l in undiluted sample, respectively, and the calibration graphs were linear up to 150 and 400 microg/l. Accuracies of urine Se were 98.9 - 99.4% by testing SRM 2670 (NIST) urine standards with RSD (between-run, n = 3) within 2.9%; and that of serum Se was 97.2% when testing a certified second-generation human serum (No. 29, #664) with RSD (between-run, n = 3) of 1.4%. The proposed method can be applied easily, directly, and accurately to the measurement of Be and Se in real samples (including six urine Se and four serum Se from patients of Blackfoot Disease in Taiwan).     

Determination of urinary arsenic by electrothermal atomic absorption spectrometry with the l'vov platform and matrix modification

Total arsenic can be determined rapidly and simply in urine by dilution with a matrix modifier containing nickel and magnesium nitrate in nitric acid. The background correction capability of Zeeman-effect electrothermal atomic absorption spectrometry effectively nullifies nonatomic absorption by urine concomitants. Accuracy and precision of the method were evaluated by the determination of total arsenic in the National Bureau of Standards' SRM 2670, Toxic Elements in Freeze-Dried Urine, and commercially available lyophilized urine material. Deviations of determined concentrations from expected values ranged from about 4 to 18 ng ml^?1 with standard deviations ranging from about 5 to 31 ng ml^?1.     

Toxicity of butyltin,phenyltin and inorganic tin compounds to sulfate‐reducing bacteria isolated from anoxic marine sediments

The toxicity of butyltin, phenyltin and inorganic tin compounds to three pure strains of sulfate‐reducing bacteria (SRB), isolated from a tributyltin (TBT)‐polluted sediment, was determined. The isolated strains were identified as belonging to the genus Desulfovibrio. A new toxicological index (GR₂₅) was developed to assay the toxicity of organotin compounds. Deleterious effects on suspended anaerobic cell cultures were observed for concentrations ranging between 500 and 600 µM for tin tetrachloride, 55 and 260 µM for triorganotins, 30 and 90 µM for diorganotins, and 1 and 6 µM for mono‐organotins. Whereas the number of substituents influenced the toxicity of organotins, the type of substituent (butyl or phenyl) proved to have little or no impact. Trisubstituted compounds (tributyl‐ and triphenyl‐tin) were less toxic to these strains of SRB than the monosubstituted forms (monobutyl‐ and monophenyl‐tin). This is the opposite trend to that currently reported for aerobic organisms. Under the given anoxic conditions, the toxicity of organotin compounds obtained yielded a significant negative correlation with the total surface area (TSA) of the tested molecules. Comparison of the TBT toxicity data observed for different microbial groups suggests that the tolerance of bacteria to organotin compounds might be related to organotin–cell wall interactions as well as to aerobic or anaerobic metabolise pathways. Copyright © 2000 John Wiley & Sons, Ltd.     

Determination of phenothiazines in human body fluids by solid-phase microextraction and liquid chromatography/tandem mass spectrometry

Eleven phenothiazine derivatives with heavy side-chains were found to be extractable from human whole blood and urine samples by solid-phase microextraction (SPME) with a polyacrylate-coated fiber. The fiber was then injected into the desorption chamber of an SPME-liquid chromatography (LC) interface for LC/tandem mass spectrometry (MS/MS) with positive ion electrospray (ES) ionization. All compounds formed base peaks due to [M + 1](+) ions by LC/ES-MS/MS. By use of LC/ES-MS/MS, the product ions produced from each [M + 1](+) ion showed base peaks due to side-chain liberation. Selected reaction monitoring (SRM) and selected ion monitoring (SIM) were compared for the detection of the 11 phenothiazine derivatives from human whole blood and urine. SRM showed much higher sensitivity than SIM for both types of sample. Therefore, a detailed procedure for the detection of drugs by SRM with SPME-LC/MS/MS was established and carefully validated. The extraction efficiencies of the 11 phenothiazine derivatives spiked into whole blood and urine were 0. 0002-0.12 and 2.6-39.8%, respectively. The regression equations for the 11 phenothiazine derivatives showed excellent linearity with detection limits of 0.2-200 ng ml(-1) for whole blood and 4-22 pg ml(-1) for urine. The intra- and inter-day precisions for whole blood and urine samples were not greater than 15.1%. The data obtained after oral administration of perazine or flupentixol to a male subject are presented.     

Progress in analytical application of an inductively coupled plasma/mass spectrometer system

Summary A method for the determination of elements in liquids using inductively coupled plasma mass spectrometry (ICP-MS) is described. The different possibilities and problems together with instrumental parameters are reviewed. After the dissolution step samples are analyzed directly without any preconcentration. Detection limits for 53 elements have been tested and are found to be less than 0.1 ng/ml. Monoisotopic elements can be detected at levels less than 0.05 ng/ml. Interference problems have been studied and hints are given to predict molecular species using algorithm implemented in software packages. The application to trace element analysis in the geological field is demonstrated with a basalt reference sample to verify figures of merit for this method. Accuracy is checked with a NBS SRM steel sample.

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Erfahrungen und Möglichkeiten mit der Anwendung eines induktiv gekoppelten Plasma/Massenspektrometer Systems

     

A simplified procedure for the determination of butyltin species in water

A method is described for the analysis of solutions containing inorganic tin and butyltin compounds. It can be used to determine total tin at a concentration of 20 ng dm^?3 using a 5 dm³ sample. The method is based on solvent extraction with dichloromethane containing tropolone and determination of the tin as inorganic tin by atomic absorption spectroscopy using electrothermal atomization. The extracted butyltin compounds can be separated by paper chromatography and the tin content of the individual spot determined as above. Observations on the stability of butyltin compounds in water at the ～2 mg dm^?3 (Sn) are included.     

Determination of Trace Butyltin Compounds in Sea Water by Gas Chromatography-Atomic Absorption Spectrometry

A gas chromatography-atomic absorption spectrometric (GC-AAS) method has been developed for the determination of trace butyltin compounds in sea water. Aqueous butyltin compounds were reduced to the volatile hydride forms by NaBH₄ and were extracted with dichloromethane simultaneously. The dichloromethane extract was concentrated under reduced pressure, followed by direct injection into the GC-AAS system for analysis. The butyltin species were separated with a 2-m glass column packed with 2% OV-101 on Chromosorb G HP (100-120 mesh). Following GC separation, each species was transferred into an electrothermally heated (800 °C) quartz furnace for atomization. The tin atoms produced from individual butyltin compound were detected at 224.6 nm by an atomic absorption spectrometer. With a sea water sample (1 L), the detection limits (3σ) for monobutyltin, dibutyltin and tributyltin were approximately 20, 20 and 70 ng Sn L^?1, respectively. The method has been applied to the analysis of trace butyltin compounds in the sea water of Keelung Harbor.     

Sensitive fluorescence labelling for analysis of organotin compounds with morin

Summary Analytical procedures based on reversed-phase high-performance liquid chromatography combined with post-column derivatization with morin for the determination of organotin compounds in peanut oil, water samples or diet mixtures are described. A mixture of the isooctylesters of monooctyl tin and dioctyl tin thioglycolic acid (ZK 30 434), a mixture of the isooctylesters of monododecyl tin and didodecyl tin thioglycolic acid (ZK 32 283) or dibutyl tin difluoride (ZK 38 068) had to be analysed. The data obtained from validation and during routine analysis show that the post-column derivatization with morin is a powerful tool for the selective and sensitive detection of organotin compounds in complicated matrices. Interferences of peaks related to the organotins and the matrix constituents were not found. The values of the limit of detection were 10 g ZK 30 434 or ZK 32 283/ml peanut oil, 60 ng ZK 38 068/ml water and 2.5 mg ZK 30 434/kg rodent diet mixture. Regarding to the repeatability, the methods described are characterized by values of the relative standard deviation of mostly less than 5%. In case of the determination of ZK 30 434 dissolved in peanut oil atomic absorption spectrometry was used to investigate the accuracy of the HPLC method. A good correlation between the HPLC and AAS data was found. The limits of quantitation were 0.25 mg ZK 30 434/ml peanut oil, 0.22 mg ZK 32 283/ml peanut oil and 1.0 g ZK 38 068/ml water. The analytical procedures were applied within the framework of the analytical service for validation of toxicological studies according to the guidelines of good laboratory practices (G.L.P.). Both the correct preparation of the formulations and the homogeneity or stability could be checked.     

Application of laser-excited atomic fluorescence spectrometry to the determination of iron

A frequency-doubled, flashlamp-pumped tunable dye laser is used to excite the Stokes direct-line atomic fluorescence transition of iron (296.7 nm/373.5 nm). Limits of detection are determined with single (0.6 ng/ml) and multipass (0.2 ng/ml) and with a l s time constant (a 0.06 ng/ml limit detection is obtained with an 8 s time constant). Noise sources limiting precision at both low (background flame emission shot and flicker noise) and high concentrations (laser pulse to pulse variability) concentrations are investigated and the technique is used for the determination of iron in simulated fresh water NBS SRM-1643), unalloyed copper (NBS SRM-394) and fly ash (NBS SRM-1633).     

Comparison of GC/MSD and GC/AED for the determination of organotin compounds in the environment

Summary Methods are described for the analysis of environmental samples like water, sediment and suspended matter for the determination of all organotin compounds (OTs) that are currently used as biocides: tributyltin (TBT), triphenyltin (TPT), tricyclohexyltin (TCT) and fenbutatin oxide (FBTO). In water also five degradation products (di and mono substituted analogs) can be determined. Alkylation using a Grignard reagent was used to obtain OT derivatives amenable to gas chromatography (GC). Both methylation and pentylation have been employed for derivatization prior to GC analysis. The present results show that derivatization efficiencies for TPT, TCT and FBTO at trace levels are higher using methylation than pentylation. Detection limits for each type of sample matrix were determined using GC/Mass Selective Detection (GC/MSD) and GC/Atomic Emission Detection (AED). In sediment and suspended matter only tri-substituted OTs (i.e. the parent compounds) could be determined. Detection limits ranged from 0.2 to 10 ng/g dry weight. FBTO, not previously detected in environmental samples, was found at levels of 4 and 11 ng/g in a suspended matter sample and a sediment sample, respectively. In water the OTs and their degradation products were determined at levels of 1–10 ng/l (as tin) using 200 ml water samples.     

Application of sample pre-oxidation of arsenite in human urine prior to speciation via on-line photo-oxidation with membrane hydride generation and ICP-MS detection

A pre-oxidation procedure which converts arsenite [As(III)] into arsenate [As(v)] was investigated in urinary arsenic speciation prior to on-line photo-oxidation hydride generation with ICP-MS detection. This sample pre-oxidation method eliminates As(III) and As(v) preservation concerns and simplifies the chromatographic separation. Four oxidants, Cl2, MnO2, H2O2 and I3-, were investigated. Chlorine (ClO-aq) and MnO2 selectively converted As(III) into As(v) in pure water samples, but the conversion was inefficient in the complex urine matrix. Oxidation of As(III) by H2O2 was least affected by the urine matrix, but the removal of excess H2O2 at pH 10 proved difficult. The most appropriate oxidant for the selective conversion of As(III) into As(v) with minimal interference from the urine matrix is I3- at pH 7. Unlike H2O2, excess oxidant can be easily removed by the addition of S2O3(2-). The I3-(-)S2O3(2-) treatment on a fortified sample of reconstituted NIST SRM 2670 freeze dried urine indicated that arsenobetaine (AsB), dimethlyarsinic acid (DMA), monomethylarsonic acid (MMA) and As(v) were not chemically degraded with recoveries ranging from 95 to 102% for all arsenicals. Sample clean-up involved pH adjustment prior to C18 filtration in order to achieve efficient As(III) conversion and quantitative recoveries of AsB and DMA. The concentrations determined in NIST SRM 2670 freeze dried urine were AsB 17.2 +/- 0.5, DMA 56 +/- 4 and MMA 10.3 +/- 0.3 with a combined total of 83 +/- 5 micrograms L-1 (+/- 2 sigma).