共查询到20条相似文献,搜索用时 31 毫秒
1.
Jiří Kohoutek Blahoslav Maršálek Luděk Bláha 《Analytical and bioanalytical chemistry》2010,397(2):823-828
In the present study, we have evaluated the effectiveness of a passive sampler for polar organic chemicals to accumulate a
group of widespread and hazardous tumor-promoting toxins produced in cyanobacterial water blooms—microcystins (MC). The previously
optimized configuration of the sampler based on polycarbonate membrane and Oasis HLB sorbent (2.75 mg/cm2) was validated under various exposure scenarios in laboratory and field. Calibration of the passive sampler conducted under
variable conditions and concentrations of MC revealed linearity of the sampling up to 4 weeks. The sampling rates of microcystins
for two different exposure scenarios were derived (e.g., MC-LR: R
s = 0.017 L/day under static and 0.087 L/d under turbulent conditions). R
s values were further used for calculations of time-weighted average concentrations in natural water. Improved sensitivity
and selectivity of the in-house-made sampler was observed in comparison with the commercially available Polar Organic Compound
Integrative Sampler (POCIS). Comparisons of grab and passive sampling methods were performed during cyanobacterial water bloom
season in the Brno reservoir, Czech Republic in 2008. Data obtained by passive sampling provided a more relevant picture of
the situation and enabled better assessment of potential risks. The present study demonstrated that the modification of POCIS
is suitable for monitoring of occurrence and retrospective estimations of microcystin water concentrations, especially with
respect to the control of drinking water quality. 相似文献
2.
A passive air sampler, using 4-amino-3-hydrazino-5-mercapto-1,2,4-triazole, was evaluated for the determination of formaldehyde in indoor environments. Chromatography paper cleaned using a 3% hydrogen peroxide solution was experimentally determined as being the optimum absorption filter for the collection of formaldehyde (0.05 microg cm(-2) formaldehyde). From a linear-regression analysis between the mass of formaldehyde time-collected on a passive air sampler and the formaldehyde concentration measured by an active sampler, the sampling rate of the passive air sampler was 1.52 L h(-1). The sampling rate, determined for the passive air sampler in relation to the temperature (19 - 28 degrees C) and the relative humidity (30 - 90%), were 1.56 +/- 0.04 and 1.58 +/- 0.07 L h(-1), respectively. The relationship between the sampling rate and the air velocity was a linear-regression within the observed range. In the case of exposed samplers, the stability of the collected formaldehyde decreased with increasing storage time (decrease of ca. 25% after 22 days); but with the unexposed samplers the stability of the blank remained relatively unchanged for 7 days (decrease of ca. 37% after 22 days). The detection limits for the passive air sampler with an exposure time of 1 day and 7 days were 10.4 and 1.48 microg m(-3), respectively. 相似文献
3.
官厅水库蓝绿藻及藻毒素初步研究 总被引:1,自引:0,他引:1
聚苹果酸最初是由微生物学家在研究青霉菌的过程中发现的,聚苹果酸的人工合成由逐步聚合法开始,但由于苹果酸单体具有3种功能基,因此得到的是支化的聚苹果酸,随后人们改用苄酯基保护一端羧基的苹果酸单体,以DCC为缩合剂,进行缩聚,但这种方法只能得到聚苹果酸低聚物。 相似文献
4.
J. Kohoutek O. Adamovský M. Oravec Z. Šimek M. Palíková R. Kopp L. Bláha 《Analytical and bioanalytical chemistry》2010,398(3):1231-1237
Microcystins are cyclic peptide toxins with hepatotoxic and tumour-promoting properties which are produced in high quantities
in freshwater cyanobacterial water blooms, and several studies have reported microcystin accumulation in fish with possible
food transfer to humans. In this study, we provide the first comparison of liquid chromatography with single mass-spectrometric
and with tandem mass-spectrometric detection for analyses of microcystins in complex fish tissue samples. Use of traditional
single mass spectrometry (i.e. monitoring of ions with m/z 519.5 for microcystin-RR and m/z 995.5 for microcystin-LR) was found to provide false-positive responses, thus overestimating the concentrations of microcystins
in the tissue samples. More selective tandem mass spectrometry seems to provide more reliable results. The concentrations
of microcystins detected by tandem mass spectrometry in fish from controlled-exposure experiments were more than 50% lower
in comparison with concentrations obtained by single mass spectrometry. Extensive analyses of edible fish parts—muscles (148
fish specimens from eight different species from five natural reservoirs with dense cyanobacterial water blooms)—showed negligible
microcystin concentrations (all analyses below the limit of detection; limit of detection of 1.2–5.4 ng/g fresh weight for
microcystin-RR, microcystin-YR and microcystin-LR in multiple reaction monitoring mode). Our findings have practical consequences
for critical re-evaluation of the health risks of microcystins accumulated in fish. 相似文献
5.
红花水溶性多糖CTP的结构研究 总被引:4,自引:0,他引:4
微囊藻毒素(Microcystins,MCs)是由淡水蓝绿藻产生的一类最常见的环七肽缩氨酸肝毒素,它们通过抑制蛋白质磷酸酶的活性产生强烈的促肝癌作用,对人和其它生物产生较大威胁,人类长期饮用微量含有MCs的水,将导致原发性肝癌(PLA),常见的MCs如MCLR,MCYR和MCRR的LD50值通常为50,70和600μg/kg(mouse,i.P.)。 相似文献
6.
A passive “badge-type” sampling device for the determination of gaseous ammonia was developed. The collection substrate is phosphoric acid. The sampler can be used for outdoor and indoor sampling of ammonia in the concentration range from 0.05 μg/m3 to 10 mg/m3. The performance was tested in the laboratory and in the field against an annualar denuder, a filter pack and an impinger technique. The intercalibration showed that the passive sampler compares very well with active samplers (r2=0.99; k=1.05). The average reproducibility of the sampler was 8%. Hence the badge sampler is well suited for the determination of ammonia in a wide range of concentrations and particularly for application under rural background conditions. The sampling rate of the device was calculated according to a simple multi-layer model. 相似文献
7.
Summary A diffusive sampler for the large scale routine determination of airborne formaldehyde was developed. Formaldehyde is sampled in a badge-type passive sampler containing a 2,4-dinitrophenylhydrazine-coated filter paper as sampling layer. Formaldehyde is immediately converted to the corresponding hydrazone, which, after desorption with acetonitrile, is separated and quantified by gradient HPLC using UV detection at 345 nm. Calibration was done via an active sampling method and showed an excellent, time- and concentration-independent linear performance of the diffusive samplers. A detection limit of about 0.05 ml/m3·h (ppm·h) and a relative standard deviation of about 10% ensured a good analytical reliability. By testing the influence of air movements at the sampler surface, a minimum air velocity of 10 cm/s was found necessary to ensure representative sampling. 相似文献
8.
Julio Llorca Cristina GutiérrezElisabeth Capilla Rafael TortajadaLorena Sanjuán Alicia FuentesIgnacio Valor 《Journal of chromatography. A》2009,1216(31):5783-5792
Two innovative integrative samplers have been developed enabling high sampling rates unaffected by turbulences (thus avoiding the use of performance reference compounds) and with negligible lag time values. The first, called the constantly stirred sorbent (CSS) consists of a rotator head that holds the sorbent. The rotation speed given to the head generates a constant turbulence around the sorbent making it independent of the external hydrodynamics. The second, called the continuous flow integrative sampler (CFIS) consists of a small peristaltic pump which produces a constant flow through a glass cell. The sorbent is located inside this cell. Although different sorbents can be used, poly(dimethylsiloxane) PDMS under the commercial twister format (typically used for stir bar sorptive extraction) was evaluated for the sampling of six polycyclic aromatic hydrocarbons and three organochlorine pesticides. These new devices have many analogies with passive samplers but cannot truly be defined as such since they need a small energy supply of around 0.5 W supplied by a battery. Sampling rates from 181 × 10−3 to 791 × 10−3 L/day were obtained with CSS and 18 × 10−3 to 53 × 10−3 with CFIS. Limits of detection for these devices are in the range from 0.3 to 544 pg/L with a precision below 20%. An in field evaluation for both devices was carried out for a 5 days sampling period in the outlet of a waste water treatment plant with comparable results to those obtained with a classical sampling method. 相似文献
9.
Hervé Plaisance 《International journal of environmental analytical chemistry》2013,93(14):1341-1352
This paper examines the results of experiments carried out in an exposure chamber to determine the wind effects on the performance of various diffusive sampler types commonly used for measuring gaseous pollutants in air. The resistance to wind of six diffusive samplers, two Palmes tubes, a badge with diffusion membrane, the EMD sampler and two radial diffusive samplers for different pollutants was compared in a range of velocities from 0 to 300?cm?s?1. For all diffusive samplers tested, an increase in uptake rate was observed with increased air velocity usually following a logarithmic function. The consequences are an underestimation in the concentration measured by the diffusive samplers for low wind velocities below 30?cm?s?1 and conversely an overestimation from 60?cm?s?1. The magnitude of wind effects depends on diffusive sampler type and exceeds an uptake rate variation of ±20% for the axial diffusion tubes and the EMD sampler. With regard to the characteristics of each diffusive sampler, the dependence of uptake rate on wind velocity was analysed and discussed. The radial diffusive samplers for benzene and particularly the ones having a large and thick porous membrane appear to be the most effective design to minimise the influence of air velocity on passive sampling. 相似文献
10.
Rocío Aguilar-Martínez M. Milagros Gómez-Gómez 《International journal of environmental analytical chemistry》2013,93(11):1100-1116
Several field trials have been carried out to assess the performance of the passive sampler Chemcatcher as aquatic monitoring technology for inorganic mercury and the organotin pollutants monobutyltin (MBT), dibutyltin (DBT) and tributyltin (TBT) in different types of waters across ten locations in Europe. Two version of the sampler were used. One for mercury that consists on 47?mm Empore? disks of iminodiacetic chelating groups as the receiving phase overlaid by a diffusion membrane of polyethersulphone; and other for organotin compounds comprising a C18 disk and a cellulose acetate membrane. Both membranes were held in a disposable polycarbonate body. The two samplers were calibrated in the laboratory in a previous work to estimate the pollutant concentration. For field sampling, the samplers were deployed for 14 days. In parallel spot samples were periodically collected during the deployment period for comparison purposes. No significant biofouling on the samplers was observed for the locations monitored. In general, water concentrations estimated by Chemcatcher were lower than those found in spot water samples due to the device only collected the soluble bioavailable fraction of target pollutants. However, the pre-concentration capability of Chemcatcher allowed the determination of the tested pollutants at levels where spot sampling fails, even in difficult water bodies such as sewage treatment plants. These advantages lead to consider this emerging methodology as a complementary tool to traditional spot sampling. 相似文献
11.
Li-Ting Lin Alicia Lishin Tsai Yves Max Tseng 《International journal of environmental analytical chemistry》2015,95(1):45-56
Furan may be formed in food under heat treatment and is highly suspected to appear in indoor air. The possible exposure to indoor furan raises concerns because it has been found to cause carcinogenicity and cytotoxicity in animals. To determine airborne furan, solid-phase microextraction (SPME) technique was utilised as a diffusive sampler. The Carboxen/Polydimethylsiloxane (CAR/PDMS, 75 μm) fibre was used, and the SPME fibre assembly was inserted into a polytetrafluoroethene tubing. Furan of known concentrations was generated in Tedlar gas bags for the evaluation of SPME diffusive samplers. After sampling, the sampler was inserted into the injection port of a gas chromatograph coupled with a mass spectrometer (GC/MS) for thermal desorption and analysis. Validation of the SPME device with active sampling by charcoal tube was performed side by side as well. The charcoal tube was desorbed by acetone before analysis with GC/MS. The experimental sampling constant of the sampler was found equal to (9.93 ± 1.28) × 10?3 (cm3 min?1) at 25°C. Furthermore, side-by-side validations between SPME device and charcoal tube showed linear relationship with r = 0.9927. The designed passive sampling device for furan has the advantages of both passive sampling and SPME technique and looks suitable for assessing indoor air quality. 相似文献
12.
Shan Y Shi X Dou A Zou C He H Yang Q Zhao S Lu X Xu G 《Journal of chromatography. A》2011,1218(13):1743-1748
Microcystins and nodularins are cyclic peptide hepatotoxins and tumour promoters from cyanobacteria. The present study describes the development, validation and practical application of a fully automated analytical method based on on-line micro solid-phase extraction-capillary liquid chromatography-tandem mass spectrometry for the simultaneous determination of seven microcystins and nodularin-R in tap water and lake water. Aliquots of just 100 μL of water samples are sufficient for the detection and quantification of all eight toxins. Selected reaction monitoring was used to obtain the highest sensitivity. Good linear calibrations were obtained for microcystins (50-2000ng/L) and nodularin-R (25-1000 ng/L) in spiked tap water and lake water samples. Excellent interday and intraday repeatability were achieved for eight toxins with relative standard deviation less than 15.7% in three different concentrations. Acceptable recoveries were achieved in the three concentrations with both tap water matrix and lake water matrix and no significant matrix effect was found in tap water and lake water except for microcystin-RR. The limits of detection (signal to noise ratio=3) of toxins were lower than 56.6 ng/L which is far below the 1 μg/L defined by the World Health Organization provisional guideline for microcystin-LR. Finally, this method was successfully applied to lake water samples from Tai lake and proved to be useful for water quality monitoring. 相似文献
13.
A passive badge-type sampling device for the determination of gaseous ammonia was developed. The collection substrate is phosphoric acid. The sampler can be used for outdoor and indoor sampling of ammonia in the concentration range from 0.05 g/m3 to 10 mg/m3. The performance was tested in the laboratory and in the field against an annualar denuder, a filter pack and an impinger technique. The intercalibration showed that the passive sampler compares very well with active samplers (r2=0.99; k=1.05). The average reproducibility of the sampler was 8%. Hence the badge sampler is well suited for the determination of ammonia in a wide range of concentrations and particularly for application under rural background conditions. The sampling rate of the device was calculated according to a simple multi-layer model.Dedicated to Professor Dr. Dieter Klockow on the occasion of his 60th birthday 相似文献
14.
The presence of estrogens in the aquatic environment has been the target of several studies in the last decade. Newly developed passive sampling techniques for polar organic chemicals show great promise for the assessment of long-time exposure of aquatic organisms to emerging contaminants. In the present work, two configurations of the Chemcatcher® passive sampler have been tested for their applicability to the analysis of seven estrogens in water. Accumulation experiments in the laboratory, to calculate the uptake rates, and a field trial show that the polar configuration of this device may be used for the efficient sampling and determination of estrogens in water. Time weighted average concentrations were determined in the field trial and compared with spot sampling concentrations. The detection of estriol using passive sampling, although not found with spot sampling, clearly demonstrates the value of this technique in assessing relevant concentrations of estrogens in the aquatic media. 相似文献
15.
Oddvar R?yset 《Fresenius' Journal of Analytical Chemistry》1998,360(1):69-73
Three different methods for sampling and determination of nitrogen dioxide in urban air are compared: an NO/NOx-monitor and an active (pumped) and a passive sampling method. For the latter two methods, sodium iodide is used as absorbent.
For weekly averages the results from the passive sampler are within 10–20% of the results for the two other methods in the
concentration range 15–30 μg NO2/m3. The detection limit for the passive sampler is 1 μg NO2/m3 (7 days), the precision is 5% and the accuracy is estimated to 20%. The active iodide method agrees very well with the NO/NOx-monitor. Compared on 24 h basis for a period of 3 months, covering a concentration range of 5–45 μg NO2/m3, the deviation between the two methods is within 5%, and the absorption capacity of the iodide reagent is excellent as the
breakthrough is below 1%.
Received: 3 December 1996 / Revised: 11 March 1997 / Accepted: 15 March 1997 相似文献
16.
A certified reference material (CRM) for microcystins has been prepared by the National Institute for Environmental Studies
(NIES). Microcystins are hepatotoxic cyclic peptides produced by cyanobacteria in eutrophic water bodies. At least seven microcystin
variants were found by HPLC analysis of the NIES CRM, of which [Dha7]microcystin-RR and -LR were the major microcystins present. Because of the lack of available standards we determined the
total microcystin concentration in the CRM by the MMPB method, and elucidated the structures of the main individual microcystin
variants following their isolation. Analyses of NMR and MS spectra indicated that the remaining minor variants in the CRM
were [D-Asp3, Dha7]microcystin-RR and -LR, and [Dha7]microcystin-YR, -ThTyrR, and -HilR. The CRM is valuable not only as a standard material for the quantitation of total microcystins
but also for the identification of individual [Dha7]microcystin variants. 相似文献
17.
Application of passive sampling devices for screening of micro-pollutants in marine aquaculture using LC-MS/MS 总被引:1,自引:0,他引:1
María Jesús Martínez Bueno 《Talanta》2009,77(4):1518-86
Knowledge on the presence of micro-pollutants, in particular emerging contaminants, such as pharmaceuticals, biocides or some pesticides, in semi-enclosed coastal areas, where fish farms are installed, is very limited. This article shows data on the presence of micro-pollutants over 1 year monitoring campaign carried out in a fish farm placed on the Mediterranean Sea. With this work, the results of the development of an analytical procedure which, makes use of passive sampling techniques (with polar organic chemical integrative samplers, POCIS, pharmaceutical configuration) and of the LC-QLIT-MS system, are presented. The development of the analytical procedure entail laboratory-based calibration with the samplers POCIS, for calculating uptake rates and sampling rates of compounds representative of a wide range of polarity (4.56 ≥ log Kow ≥ −0.12). The uptake of the target compounds in the sampler POCIS, follows a linear pattern for most compounds, and sampling rates varied from 0.001 to 0.319 l/d. The calibration experiments have shown that POCIS pharmaceutical configuration could be used for sampling other non-target compounds, such as pesticides and biocides with a log Kow ≤ 4. The sampling rates for each selected compound were obtained using spiked seawater for further estimation of time-weighted average (TWA) concentration of micro-pollutants in the water column, during the field study. An analytical method was developed with the LC-QLIT-MS system and validated to ensure a satisfactory performance for the detection of the target micro-pollutants in water. The limits of detection (LODs) achieved were between 0.01 and 1.50 μg/l. During the monitoring campaign, among the selected compounds, metronidazole, erythromycin, simazine, atrazine, diuron, terbutryn, irgarol, trimethoprim, carbaryl, flumequine, TCMTB and diphenyl sulphone (DPS) were detected. Most of target compounds found were at average concentrations which ranged from 0.01 to 75 ng/l. Irgarol, simazine, diuron, atrazine and DPS were the micro-pollutants most frequently detected over the period of the monitoring programme carried out. 相似文献
18.
Sonia Herranz Markéta Bocková María Dolores Marazuela Ji?í Homola María Cruz Moreno-Bondi 《Analytical and bioanalytical chemistry》2010,398(6):2625-2634
A surface plasmon resonance (SPR) biosensor for the detection of microcystins (MCs) in drinking water has been developed.
Several assay formats have been evaluated. The selected format is based on a competitive inhibition assay, in which microcystin-LR
(MCLR) has been covalently immobilized onto the surface of an SPR chip functionalized with a self-assembled monolayer. The
influence of several factors affecting sensor performance, such as the nature and concentration of the antibody, the composition
of the carrier buffer, and the blocking and regeneration solutions, has been evaluated. The optimized SPR biosensor provides
an IC50 0.67 ± 0.09 μg L−1, a detection limit of 73 ± 8 ng L−1, and a dynamic range from 0.2 to 2.0 μg L−1 for MCLR. Cross-reactivity to other related MCs, such as microcystin-RR (88%) and microcystin-YR (94%), has also been measured.
The SPR biosensor can perform four simultaneous determinations in 60 min, and each SPR chip can be reused for at least 40
assay–regeneration cycles without significant binding capacity loss. The biosensor has been successfully applied to the direct
analysis of MCLR in drinking water samples, below the provisional guideline value of 1 μg L−1 established by the World Health Organization for drinking water. 相似文献
19.
SPE and LC-MS/MS determination of 14 illicit drugs in surface waters from the Natural Park of L’Albufera (València, Spain) 总被引:1,自引:0,他引:1
Pablo Vazquez-Roig Vicente Andreu Cristina Blasco Yolanda Picó 《Analytical and bioanalytical chemistry》2010,397(7):2851-2864
A simple and robust method using solid-phase extraction (SPE) and liquid chromatography tandem mass spectrometry (LC-MS/MS)
for the simultaneous determination of 14 drugs of abuse and their metabolites (cocainics, amphetamine-like compounds, cannabinoids,
and opiates) in surface waters has been developed. Seven SPE adsorbents (Oasis HLB, Oasis MCX, Oasis Wax, Supelselect HLB,
Strata-X, Strata-XCW), amount of sorbent bed, water volume, and pH were investigated. The highest recoveries, as well as the
simplest protocol, were obtained for Oasis HLB cartridges (6 mL/200 mg) using 250 mL of water. The proposed method was linear
in a concentration range from 0.03–6 to 300–60,000 ng/L depending on the compound, with correlation coefficients higher than
0.998. Matrix effects have been studied in surface water samples, and several isotope-labeled internal standards have been
evaluated as a way to compensate the signal suppression observed. Limits of detection (LODs) and quantification (LOQs) ranged
from 0.01 to 1.54 ng/L and from 0.03 to 5.13 ng/L, respectively. Recoveries were 71–102% at the LOQ level and 77–104 at 50 ng/L.
The intra-day and intermediate precisions were from 1% to 8% and from 2% to 11%, respectively. The present work reports for
the first time the occurrence of drugs of abuse residues in surface water samples from the Natural Park of L’Albufera (Valencia,
Spain). Codeine, cocaine, benzoylecgonine, ecgonine methylester, amphetamine, 3,4-methylendioxy methamphetamine, morphine,
and methadone were quantified with median values of 11.10, 0.02, 5.59, 0.08, 0.21, 0.75 and 0.14 ng/L respectively, and 11-nor-9-carboxy-Δ9-tetrahydrocannabinol
was detected in one sample at levels <LOQ. 相似文献
20.
A simple and cost effective permeation passive sampler equipped with a polydimethylsiloxane (PDMS) membrane was designed for the determination of time-weighted average (TWA) concentrations of volatile organic compounds (VOCs) in air. Permeation passive samplers have significant advantages over diffusive passive samplers, including insensitivity to moisture and high face velocities of air across the surface of the sampler. Calibration constants of the sampler towards 41 analytes belonging to alkane, aromatic hydrocarbon, chlorinated hydrocarbon, ester and alcohol groups were determined. The calibration constants allowed for the determination of the permeability of PDMS towards the selected analytes. They ranged from 0.026 cm2 min−1 for 1,1-dichloroethylene to 0.605 cm2 min−1 for n-octanol. Further, the mechanism of analyte transport across PDMS membranes allowed for the calibration constants of the sampler to be estimated from the linear temperature programmed retention indices (LTPRI) of the analytes, determined using GC columns coated with pure PDMS stationary phases. Statistical analysis using Student's t test indicated that there was no significant difference at the 95% probability level between the experimentally obtained calibration constants and those estimated using LTPRI for most analyte groups studied. This correlation allows the estimation of the calibration constants of compounds not known to be present at the time of sampler deployment, which makes it possible to determine parameters like total petroleum hydrocarbons in the vapor phase. 相似文献