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1.
A survey of contamination of surface and drinking waters around Lake Maggiore in Northern Italy with polar anthropogenic environmental
pollutants has been conducted. The target analytes were polar herbicides, pharmaceuticals (including antibiotics), steroid
estrogens, perfluorooctanesulfonate (PFOS), perfluoroalkyl carboxylates (including perfluorooctanoate PFOA), nonylphenol and
its carboxylates and ethoxylates (NPEO surfactants), and triclosan, a bactericide used in personal-care products. Analysis
of water samples was performed by solid-phase extraction (SPE) then liquid chromatography–triple-quadrupole (tandem) mass
spectrometry (LC–MS–MS). By extraction of 1-L water samples and concentration of the extract to 100 μL, method detection limits
(MDLs) as low as 0.05–0.1 ng L−1 were achieved for most compounds. Lake-water samples from seven different locations in the Southern part of Lake Maggiore
and eleven samples from different tributary rivers and creeks were investigated. Rain water was also analyzed to investigate
atmospheric input of the contaminants. Compounds regularly detected at very low concentrations in the lake water included:
caffeine (max. concentration 124 ng L−1), the herbicides terbutylazine (7 ng L−1), atrazine (5 ng L−1), simazine (16 ng L−1), diuron (11 ng L−1), and atrazine-desethyl (11 ng L−1), the pharmaceuticals carbamazepine (9 ng L−1), sulfamethoxazole (10 ng L−1), gemfibrozil (1.7 ng L−1), and benzafibrate (1.2 ng L−1), the surfactant metabolite nonylphenol (15 ng L−1), its carboxylates (NPE1C 120 ng L−1, NPE2C 7 ng L−1, NPE3C 15 ng L−1) and ethoxylates (NPE
n
Os, n = 3-17; 300 ng L−1), perfluorinated surfactants (PFOS 9 ng L−1, PFOA 3 ng L−1), and estrone (0.4 ng L−1). Levels of these compounds in drinking water produced from Lake Maggiore were almost identical with those found in the lake
itself, revealing the poor performance of sand filtration and chlorination applied by the local waterworks. 相似文献
2.
Dolores Barranco Martínez María Martínez Galera Piedad Parrilla Vázquez M. Dolores Gil García 《Chromatographia》2007,66(7-8):533-538
Liquid chromatography with electrospray mass spectrometry (LC–ESI-MS) instrumentation equipped with a single quadrupole mass
filter has been used to determine several benzoylphenylurea insecticides (diflubenzuron, triflumuron, hexaflumuron, lufenuron
and flufenoxuron). Chromatographic and MS parameters were optimised to obtain the best sensitivity and selectivity for all
pesticides. Solid-phase extraction (SPE) using C18 cartridges was applied for preconcentration of pesticide trace levels in river water samples. Recoveries of benzoylphenylurea
pesticides from spiked river water (0.01 and 0.025 μg L−1) were between 73 and 110% and detection limits were between 3.5 and 7.5 ng L−1. The applicability of the method to the determination of benzoylphenylurea insecticides in spiked cucumber, green beans,
tomatoes and aubergines was evaluated. Samples were extracted into dichloromethane without any clean-up step. The limits of
detection ranged from 1.0 to 3.2 ng mL−1 (0.68 and 2.13 μg kg−1 in the vegetable samples). Mean recoveries ranged from 79 to 114% at spiking levels of 0.01 and 0.03 mg kg−1. The method was applied to determine traces of benzoylphenylureas in both river water and vegetable samples with precision
values lower than 10%. Interferences due to the matrix effect were overcome using matrix-matched standards. 相似文献
3.
A multi-component method focussing on thorough sample preparation has been developed for simultaneous analysis of swine manure
for three classes of antibiotic—tetracyclines, sulfonamides, and tylosin. Liquid manure was initially freeze-dried and homogenised
by pulverization before extraction by pressurised liquid extraction. The extraction was performed at 75°C and 2,500 psig in
three steps using two cycles with 0.2 mol L−1 citric acid buffer (pH 4.7) and one cycle with a mixture of 80% methanol with 0.2 mol L−1 citric acid (pH 3). After liquid–liquid extraction with heptane to remove lipids, the pH of the manure was adjusted to 3
with formic acid and the sample was vacuum-filtered through 0.6 μm glass-fibre filters. Finally the samples were pre-concentrated
by tandem SPE (SAX-HLB). Recoveries were determined for manure samples spiked at three concentrations (50–5,000 μg kg−1 dry matter); quantification was achieved by matrix-matched calibration. Recoveries were >70% except for oxytetracycline (42–54%),
sulfadiazine (59–73%), and tylosin (9–35%) and did not vary with concentration or from day-to-day. Limits of quantification
(LOQ) for all compounds, determined as a signal-to-noise ratio of 10, were in the range 10–100 μg kg−1 dry matter. The suitability of the method was assessed by analysis of swine manure samples from six different pig-production
sites, e.g. finishing pigs, sows, or mixed production. Residues of antibiotics were detected in all samples. The largest amounts
were found for tetracyclines (up to 30 mg kg−1 dry matter for the sum of CTC and ECTC). Sulfonamides were detected at concentrations up to 2 mg kg−1 dry matter (SDZ); tylosin was not detected in any samples.
相似文献
4.
Analytical development for analysis of pharmaceuticals in water samples by SPE and GC–MS 总被引:3,自引:0,他引:3
An analytical procedure involving solid-phase extraction (SPE) and gas chromatography–mass spectrometry (GC–MS) has been developed
for determination of pharmaceutical compounds (aspirin, caffeine, carbamazepine, diclofenac, ketoprofen, naproxen, ibuprofen,
clofibrate, clofibric acid, and gemfibrozil) in a variety of aqueous samples (wastewater and surface water). After filtration,
samples were extracted and concentrated using C18 or HLB cartridges, depending on the type of compound. Sample storage conditions were checked and optimized to ensure preservation
of the pharmaceutical substance, taking into consideration environmental sampling conditions. For most of the pharmaceuticals
monitored, recovery was in the range 53 to 99% and the variability was below 15% for the complete procedure, with limits of
detection ranging from 0.4 to 2.5 ng L−1, depending on the compound. The methods were successfully applied to monitoring of pharmaceutical contamination of the Seine
estuary. Concentrations varied from several dozens of nanograms per liter for surface waters to several hundreds of nanograms
per liter for wastewaters. 相似文献
5.
Arsenic-speciation analysis in marine samples was performed by high-pressure liquid chromatography (HPLC) with ICP–MS detection.
Separation of eight arsenic species—AsIII, MMA, DMA, AsV, AB, TMAO, AC and TeMAs+—was achieved on a C18 column with isocratic elution (pH 3.0), under which conditions AsIII and MMA co-eluted. The entire separation was accomplished in 15 min. The HPLC–ICP–MS detection limits for the eight arsenic
species were in the range 0.03–0.23 μg L−1 based on 3σ for the blank response (n=5). The precision was calculated to be 2.4–8.0% (RSD) for the eight species. The method was successfully applied to several
marine samples, e.g. oysters, fish, shrimps, and marine algae. Low-power microwave digestion was employed for extraction of
arsenic from seafood products; ultrasonic extraction was employed for the extraction of arsenic from seaweeds. Separation
of arsenosugars was achieved on an anion-exchange column. Concentrations of arsenosugars 2, 3, and 4 in marine algae were
in the range 0.18–9.59 μg g−1.
This paper was presented at the European Winter Conference 2005 相似文献
6.
Perreau F Bados P Kerhoas L Nélieu S Einhorn J 《Analytical and bioanalytical chemistry》2007,388(5-6):1265-1273
Two alternatives for the rapid simultaneous quantification of six sulfonylurea herbicides and five of their main degradation
products in natural water are proposed. For concentration, the compounds were extracted on a polystyrene–divinylbenzene solid
phase under pH and elution conditions that suppressed any hydrolysis. The eluates were analysed by liquid chromatography coupled
to electrospray tandem mass spectrometry within 20 min. The whole method was validated and shown to give no hydrolysis artefacts.
The application of off-line and on-line SPE of sulfonylureas enabled the 0.1 μg L−1 and 1 ng L−1 LOQ levels to be reached, respectively. The on-line SPE–LC–MS–MS method allowed the accurate quantitation of all sulfonylureas
and three degradation products at 0.1 μg L−1 or below in natural water, with an average repeatability of 8%. 相似文献
7.
Zhao RS Wang X Wang X Lin JM Yuan JP Chen LZ 《Analytical and bioanalytical chemistry》2008,390(6):1671-1676
In recent years, bamboo charcoal, a new kind of material with special microporous and biological characteristics, has attracted
great attention in many application fields. In this paper, the potential of bamboo charcoal to act as a solid-phase extraction
(SPE) adsorbent for the enrichment of the environmental pollutant perfluorooctanoic acid, which is one of the newest types
of persistent organic pollutants in the environment, has been investigated. Important factors that may influence the enrichment
efficiency—such as the eluent and its volume, the flow rate of the sample, the pH of the sample and the sample volume—were
investigated and optimized in detail. Under the optimum conditions, the limit of detection for PFOA was 0.2 ng L−1. The experimental results indicated that this approach gives good linearity (R
2 = 0.9995) over the range 1–1000 ng L−1 and good reproducibility, with a relative standard deviation of 4.0% (n = 5). The proposed method has been applied to the analysis of real water samples, and satisfactory results were obtained.
The average spiked recoveries were in the range 79.5∼118.3 %. All of the results indicate that the proposed method could be
used for the determination of PFOA at ultratrace levels in water samples. 相似文献
8.
The electrochemical behavior of the ofloxacin–copper complex, Cu(II)L2, at a mercury electrode, and the interaction of DNA with the complex have been investigated. The experiments indicate that
the electrode reaction of Cu(II)L2 is an irreversible surface electrochemical reaction and that the reactant is of adsorbed character. In the presence of DNA,
the formation of the electrochemically non-active complexes Cu(II)L2-DNA, results in the decrease of the peak current of Cu(II)L2. Based on the electrochemical behavior of the Cu(II)L2 with DNA, binding by electrostatic interaction is suggested and a new method for determining nucleic acid is proposed. Under
the optimum conditions, the decrease of the peak current is in proportional to the concentration of nucleic acids in the range
from 3 × 10−8 to 3 × 10−6 g · mL−1 for calf thymus DNA, from 1.6 × 10−8 to 9.0 × 10−7 g · mL−1 for fish sperm DNA, and from 3.3 × 10−8 to 5.5 × 10−7 g · mL−1 for yeast RNA. The detection limits are 3.3 × 10−9, 6.7 × 10−9 and 8.0 × 10−9 g · mL−1, respectively. The method exhibits good recovery and high sensitivity in synthetic samples and in real samples. 相似文献
9.
A rapid, sensitive, and accurate high-performance liquid-chromatographic–mass spectrometric (HPLC–MS) method, with estazolam as internal standard, has been developed and validated for determination of aripiprazole in human plasma. After liquid–liquid extraction the compound was analyzed by HPLC on a C18 column, with acetonitrile—30 mm ammonium acetate containing 0.1% formic acid, 58:42 (v/v), as mobile phase, coupled with electrospray ionization mass spectrometry (ESI-MS). The protonated analyte was quantified by selected-ion recording (SIR) with a quadrupole mass spectrometer in positive-ion mode. Calibration plots were linear over the concentration range 19.9–1119.6 ng mL−1. Intra-day and inter-day precision (CV%) and accuracy (RE%) for quality-control samples (37.3, 124.4, and 622.0 ng mL−1) ranged between 2.5 and 9.0% and between 1.3 and 3.5%, respectively. Extraction recovery of aripiprazole from plasma was in the range 75.8–84.1%. The method enables rapid, sensitive, precise, and accurate measurement of the concentration of aripiprazole in human plasma. 相似文献
10.
Huang KJ Zhang M Xie WZ Zhang HS Feng YQ Wang H 《Analytical and bioanalytical chemistry》2007,388(4):939-946
A simple, sensitive, selective, and low-cost method is proposed for rapidly determining nitric oxide (NO) in some rat tissues.
Polymer monolith microextraction (PMME) using a poly(methacrylic acid–ethylene glycol dimethacrylate) (MAA-EGDMA) monolithic
column was combined with derivatization of NO using 1,3,5,7-tetramethyl-8-(3′,4′-diaminophenyl)-difluoroboradiaza-s-indacene (TMDABODIPY), and this was used to analyze the derivatives of NO by high-performance liquid chromatography (HPLC)
with fluorescence detection at λ
ex/λ
em = 498/507 nm. The baseline separation of TMDABODIPY and its NO derivative is performed under simple conditions in which a
C18 column is used and eluted with 50 mmol L−1 ethanolamine and methanol. The conditions for the extraction of NO derivatives were optimized. The limit of detection of
NO was 2 × 10−12 mol L−1 (S/N = 3). The linearity range of the method was 9 × 10−11−4.5 × 10−8 mol L−1. The interday and intraday relative standard deviations were less than 5%. The proposed method was successfully applied to
the determination of NO levels in some rat tissue samples including heart, kidney, and liver with recoveries varying from
87.1 to 95.2%. 相似文献
11.
An analytical procedure for precisely determining the stoichiometry of NaxCoO2-type superconductor material is presented. Sodium and cobalt contents, ranging between 3.5 and 11 mg L−1 and 18 and 32 mg L−1, respectively, were measured simultaneously using CID–ICP–OES. Sodium was found to significantly lower the emission intensity
of cobalt, so the addition of 6.4 g L−1 of the ionization buffer LiCl was required to compensate for this effect. The recoveries and precisions of the measurements
were significantly increased by internal standardization using yttrium: Co(II) emission intensities at 230.786 nm, 237.862 nm,
and 238.346 nm can be corrected using Y ion emission intensities, as can the atomic emissions of Co at 345.351 nm and Na at
589.592 nm. The cobalt contents of three real superconductor samples were independently verified by complexometric titration
using EDTA. The valence state of cobalt was determined with a relative uncertainty of ~0.5% by redox titration using sodium
oxalate as reductive agent and Ce(SO4)2 solution. The final stoichiometries of the superconductor samples can be calculated using the Na and Co contents, and the
Co valence state. Conclusions about the quality of the prepared samples in terms of phase purity and presence of side products
are drawn. 相似文献
12.
Popp M Hann S Mentler A Fuerhacker M Stingeder G Koellensperger G 《Analytical and bioanalytical chemistry》2008,391(2):695-699
A novel method employing high-performance cation chromatography in combination with inductively coupled plasma dynamic reaction
cell mass spectrometry (ICP–DRC–MS) for the simultaneous determination of the herbicide glyphosate (N-phosphonomethylglycine) and its main metabolite aminomethyl phosphonic acid (AMPA) is presented. P was measured as 31P16O+ using oxygen as reaction gas. For monitoring the stringent target value of 0.1 μg L−1 for glyphosate, applicable for drinking and surface water within the EU, a two-step enrichment procedure employing Chelex
100 and AG1-X8 resins was applied prior to HPIC–ICP–MS analysis. The presented approach was validated for surface water, revealing
concentrations of 0.67 μg L−1 glyphosate and 2.8 μg L−1 AMPA in selected Austrian river water samples. Moreover, investigations at three waste water-treatment plants showed that
elimination of the compounds at the present concentration levels was not straightforward. On the contrary, all investigated
plant effluents showed significant amounts of both compounds. Concentration levels ranged from 0.5–2 μg L−1 and 4–14 μg L−1 for glyphosate and AMPA, respectively. 相似文献
13.
Arizaga Rodríguez S Blanco González E Alvarez Llamas G Montes-Bayón M Sanz-Medel A 《Analytical and bioanalytical chemistry》2005,383(3):390-397
Two methods for separation of transferrin (Tf) sialoforms, capillary electrophoresis (CE) and high performance liquid chromatography
(HPLC) with conventional UV absorbance detection, have been investigated and compared. First, conditions affecting the separation
of the Tf isoforms by capillary zone electrophoresis and HPLC were carefully optimized. The use of 15 mmol L−1 borate buffer (pH 8.4) containing 3 mmol L−1 diaminobutane (DAB) as additive enabled good separation of the Tf isoforms by CE (75 cm×50 μm i.d. fused silica capillary)
at 25 kV. In HPLC, a gradient of ammonium acetate (from 0 to 250 mmol L−1 in 45 min) buffered at pH 6 (Tris-HCl) proved suitable for separation of Tf isoforms on a Mono-Q HR 5/5 anion-exchange column.
On-line specific detection of the iron associated with the different Tf isoforms, after Fe saturation, by inductively coupled
plasma mass spectrometry (ICP–MS) was studied in detail to compare its analytical performance with UV detection. For both
CE and HPLC an octapole reaction system (ORS) ICP–MS instrument was used to minimize polyatomic interferences on the 56Fe major isotope. Limits of detection of the different isoforms were in the range of 0.02–0.04 μmol L−1 Tf for HPLC–ICP (ORS)–MS. This hybrid technique proved more selective and reliable detection of transferrin isoforms with
2, 3, 4, 5, and 6 sialic acid residues (S2, S3, S4, S5, and S6) in real serum samples. Interesting results from iron speciation of Tf in serum from healthy individuals and from pregnant
women are given. 相似文献
14.
Bonnefoy C Menudier A Moesch C Lachâtre G Mermet JM 《Analytical and bioanalytical chemistry》2005,383(2):167-173
Quantification of chromium in whole blood has been performed by ICP–quadrupole MS. The spectrometer was equipped with a dynamic
reaction cell (DRC) with ammonia as reaction gas. The rejection parameter q (RPq) of the DRC and the flow rate of ammonia (NH3) were optimized and set at 0.7 and 0.6 mL min−1, respectively. Blood was diluted 1:51 (v/v) with an aqueous solution containing 0.1 mg L−1 NH4OH, 0.1 g L−1 EDTA, 5 mg L−1
n-butanol, and 0.1‰ Triton X100. Non-spectral matrix effects observed when using the DRC were confirmed by use of vanadium.
External calibration with blank and standard solutions prepared in purified water led to biased results for quality control
samples. Standard addition calibration was therefore used and its validity verified. By comparing the slopes and calculating
residues, it was proved that the plot obtained with standard additions and the plot obtained from blood samples of different
concentrations were aligned down to 0.05 μg L−1 after dilution. 相似文献
15.
Although there is increasing concern about residues from personal care products entering the aquatic environment and their
potential to accumulate to levels that pose a health threat to humans and wildlife, we still know little about the extent
and magnitude of their presence in the aquatic environment. In this study we describe a procedure for isolation, and subsequent
determination, of compounds commonly added to personal care products. The compounds of interest include UV filters with the
commercial name Eusolex (homosalate, 4-methylbenzylidenecamphor, benzophenone-3, octocrylene, butylmethoxydibenzoylmethane,
ethylhexyl methoxycinnamate) and two common anti-microbial agents, clorophene and triclosan. Water samples were filtered,
acidified, and extracted by use of solid-phase extraction. Extracted compounds were then derivatised before analysis by gas
chromatography–mass spectroscopy. By use of our method we obtained limits of detection of 13–266 ng L−1 for UV filters, and 10–186 ng L−1 for triclosan and clorophene. Recoveries were 82–98% for deionised water and 50–98% for natural water (seawater, pool water,
lake water, and river water). Samples collected in Slovenia included seventeen recreational waters (seawater, pool water,
lake water, and river water; August 2004) and four wastewaters (January 2005). The most abundant UV filter was benzophenone-3
(11–400 ng L−1). Of the two anti-microbial agents studied, trace amounts, only, of triclosan were present in the river Kolpa (68 ng L−1) and in an hospital effluent (122 ng L−1). 相似文献
16.
MSPD procedure for determining buprofezin,tetradifon, vinclozolin,and bifenthrin residues in propolis by gas chromatography–mass spectrometry 总被引:1,自引:0,他引:1
dos Santos TF Aquino A Dórea HS Navickiene S 《Analytical and bioanalytical chemistry》2008,390(5):1425-1430
A simple and effective extraction method based on matrix solid-phase dispersion (MSPD) was developed to determine bifenthrin,
buprofezin, tetradifon, and vinclozolin in propolis using gas chromatography–mass spectrometry in selected ion monitoring
mode (GC–MS, SIM). Different method conditions were evaluated, for example type of solid phase (C18, alumina, silica, and Florisil), the amount of solid phase and eluent (n-hexane, dichloromethane, dichloromethane–n-hexane (8:2 and 1:1, v/v) and dichloromethane–ethyl acetate (9:1, 8:2 and 7:3, v/v)). The best results were obtained using 0.5 g propolis, 1.0 g silica as dispersant sorbent, 1.0 g Florisil as clean-up sorbent,
and dichloromethane–ethyl acetate (9:1, v/v) as eluting solvent. The method was validated by analysis of propolis samples fortified at different concentration levels
(0.25 to 1.0 mg kg−1). Average recoveries (four replicates) ranged from 67% to 175% with relative standard deviation between 5.6% and 12.1%. Detection
and quantification limits ranged from 0.05 to 0.10 mg kg−1 and 0.15 to 0.25 mg kg−1 propolis, respectively. 相似文献
17.
A convenient, selective and sensitive liquid chromatographic-electrospary ionization mass spectrometry (LC–ESI–MS) method
was developed and validated to determine lovastatin in human plasma. The analyte was extracted from human plasma samples by
typical liquid–liquid extraction, separated on a C18 column by using the mobile phase consisting of water–methanol (13:87, v/v). Simvastatin was used as the internal standard (IS). The method was linear within the range of 0.1–20 ng mL−1. The lower limit of quantification (LLOQ) was 0.1 ng mL−1. The intra- and inter-run precision, calculated from quality control (QC) samples was less than 10.2%. The accuracy as determined
from QC samples was in the range of 99.3–102.9% for the analyte. The mean recoveries for lovastatin and IS were 84.8 and 88.0%,
respectively. The method was successfully applied for evaluation of the pharmacokinetic of lovastatin in healthy volunteers. 相似文献
18.
Comparison of adsorbents for on-line solid-phase extraction of polycyclic aromatic hydrocarbons before liquid chromatography with UV detection 总被引:1,自引:0,他引:1
Summary On-line solid-phase extraction (SPE) coupled with reversed-phase liquid chromatography and UV detection at 254 nm has been
used for the determination of trace-level polycyclic aromatic hydrocarbons (PAH) in soil extracts. Five commercially available
adsorbents (C8, C18, PLRP-S, PRP-1, and Bond-Elut Env) were evaluated. Results showed that recovery of the PAH decreased with increasing molecular
weight, because of their poorer solubility. Recovery of high-molecular-weight PAH was significantly improved by addition of
10% (v/v) acetonitrile to the sample before loading of the SPE adsorbent. PAH recovery ranged from 64.0 to 108% when a 50
mL sample spiked with 1 μg L−1 was applied to these adsorbents. Determination of PAH was possible with detection limits below 0.05 μg L−1, which corresponds to 0.2 μg kg−1 soil. The method was successfully used to determine PAH in soil extracts. 相似文献
19.
The amount of volatile dimethylselenide (DMSe) in breath has been monitored after ingestion of sub-toxic amounts of selenium
(300 μg 77Se, as selenite) by a healthy male volunteer. The breath samples were collected in Tedlar bags every hour in the first 12 h
and then at longer intervals for the next 10 days. The samples were subjected to speciation analysis for volatile selenium
compounds by use of cryotrapping–cryofocussing–GC–ICP–MS. Simultaneously, all urine was collected and subjected to total selenium
determination by use of ICP–MS. By monitoring m/z 82 and 77, background or dietary selenium and selenium from the administered selenite were simultaneously determined in the
urine and in the breath—dietary selenium only was measured by monitoring m/z 82 whereas the amount of spiked 77Se (99.1% [enriched spike]) and naturally occurring selenium (7.6% [natural abundance]) were measured by monitoring m/z 77. Quantification of DMSe was performed by using DMSe gas samples prepared in Tedlar bags (linear range 10–300 pg, R
2=0.996, detection limit of Se as DMSe was 10 pg Se, or 0.02 ng L−1, when 0.5 L gas was collected). Dimethylselenide was the only selenium species detected in breath samples before and after
the ingestion of 77Se-enriched selenite. Additional DM77Se was identified as early as 15 min after ingestion of the isotopically-labelled selenite. Although the maximum concentration
of 77Se in DMSe was recorded 90 min after ingestion, the natural isotope ratio for selenium in DMSe (77/82) was not reached after
20 days. The concentration of DMSe correlated with the total Se concentration in the urine during the experiment (R
2=0.80). Furthermore, the sub-toxic dose of 300 μg selenium led to a significant increase of DMSe and renal excretion of background
selenium, confirming that selenium ingested as selenite is homeostatically controlled by excretion. The maximum concentration
of DMSe resulting from the spiked selenite was 1.4 ng Se L−1 whereas the dietary background level was less than 0.4 ng Se L−1. Overall excretion as DMSe was calculated to be 11.2% from the ingested selenite within the first 10 days whereas urinary
excretion accounts for nearly 18.5%. 相似文献
20.
Summary A method is reported for the determination of dibutyltin (DBT), diphenyltin (DPhT), tributyltin (TBT), and triphenyltin (TPhT)
species at the nanogram per litre concentration level in natural water samples. Analytes were isolated from samples by solid-phase
extraction and analysed both off-line and on-line by reversed-phase high-performance liquid chromatography with post-column
derivatization and fluorimetric detection. Several SPE cartridges and eluents were evaluated; C18 enrichment and elution with a mixture of methanol, acetic acid, and water was found most suitable. Preconcentration factors
up to 250 can be achieved when a 500-mL sample is processed. Detection limits, recovery rates, and the precision of the whole
process have been determined. The method has been applied to the determination of organotin species in spiked natural water
samples collected on the NW Mediterranean coast. Recovery rates range from 75 to 110% and detection limits are at the low
ng L−1 level (1–3 ng Sn L−1 for DPhT, DBT, and PhT and 40 ng Sn L−1 for TBT when 250 mL spiked sea water is processed.) 相似文献