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1.
A method was developed for sampling and selective quantitative determination of typical volatile organic compounds (VOCs) in ambient urban air. A mobile and self-contained dual-channel air sampling tool based on solid phase adsorption was constructed. A simple calibration procedure circumventing the adsorption/desorption process was designed. The method was validated for seven “key-analytes”: n-hexane, 3-methyl-2-pentene, benzene, tetrachloroethene, styrene, 1,2,4-trimethylbenzene and acetophenone. The complete air sampling equipment is easily accommodated in a business suitcase. The lower limits of the practical working ranges are between 0.1 μg m–3 (tetrachloroethene) and 1.2 μg m–3 (benzene). Air samples were collected at a location in Salzburg with heavy motor vehicle traffic and measured in order to prove a satisfactory method performance under practical monitoring conditions. 相似文献
2.
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
3.
Competitive adsorption on adsorptive solid-phase microextraction (SPME) fibres implies careful determination of operating
conditions for reliable quantitative analysis of VOCs in indoor air. With this objective, two analytical approaches, involving
non-equilibrium and equilibrium extraction, were compared. The average detection limit obtained for GC-MS analysis of nine
VOCs by the equilibrium method is 0.2 μg m−3, compared with 1.9 μg m−3 with the non-equilibrium method. The effect of the relative humidity of the air on the calibration plots was studied, and
shown to affect acetone adsorption only. Hence, the concentrations that can be accurately determined are up to 9 μmol m−3. The methods were then applied to indoor air containing different concentrations of VOCs. The non-equilibrium method, involving
short extraction time, can be used for detection of pollution peaks whereas equilibrium extraction is preferable for measurement
of sub-μg m−3 ground concentration levels.
相似文献
4.
Staimer N Delfino RJ Bufalino C Fine PM Sioutas C Kleinman MT 《Analytical and bioanalytical chemistry》2005,383(6):955-962
A personalized, miniaturized air sampling system was evaluated to estimate the daily exposure of pediatric asthmatics to nitrogen
dioxide (NO2). The lightweight device (170 g) uses a sampling pump connected to a solid sorbent tube containing triethanolamine (TEA)-impregnated
molecular sieve. The pump is powered by a 9 V battery and samples air over a 24 h period at a collection rate of 0.100 L/min.
After exposure, the solid sorbent is removed from the tubes for spectrophotometric analysis (Griess Assay). The lower detection
limit of the overall method for NO2 is 11 μg/m3. The linearity, precision and accuracy of the sampler was evaluated. Different NO2 concentrations generated in the laboratory (range: 50 to 340 μg/m3) were simultaneously measured by the TEA tube samplers and colocated continuous chemiluminescent NOx analyzers (reference method). The coefficient of determination for the laboratory test derived from ordinary linear regression
(OLR) was r
2=0.99 (y
OLR=0.94x−4.58) and the precision 3.6%. Further, ambient NO2 concentrations in the field (range: 10–120 μg/m3) were verified with continuous chemiluminescent monitors next to the active samplers. Reweighted least squares analysis (RLS)
based on the least median squares procedure (LMS) resulted in a correlation of r
2=0.68 for a field comparison in Riverside, CA (y
RLS=1.01x−0.94) and r
2=0.92 in Los Angeles, CA (y
RLS=1.31x−7.12). The precision of the TEA tube devices was 7.4% (at 20–60 μg/m3 NO2) under outdoor conditions. Data show that the performance of this small active sampling system was satisfactory for measuring
environmental concentrations of NO2 under laboratory and field conditions. It is useful for personal monitoring of NO2 in environmental epidemiology studies where daily measurements are desired. 相似文献
5.
Ramón Batlle Anders Colmsjö Ulrika Nilsson 《Analytical and bioanalytical chemistry》2001,369(6):524-529
An SPME method was developed for sampling gaseous 2,4-toluene diisocyanate (2,4-TDI) involving derivatisation of the isocyanate
by reacting with dibutylamine (DBA). The TDI-DBA derivative thus formed was determined by LC–MS–MS utilising atmospheric pressure
chemical ionisation (APCI). As a first step, DBA was loaded onto a poly(dimethylsiloxane)/divinylbenzene (PDMS–DVB) fibre
coating by direct vapour-phase extraction of a highly concentrated diethyl ether solution of DBA. The DBA-loaded fibre was
then exposed to an artificially generated atmosphere of gaseous 2,4-TDI. The linearity of the method ranged from 52.8 to 3100
μg m–3 (6.8 to 400 ppbv) with a sampling time of 60 min. The proposed method has been applied to 2,4-TDI determination in an artificially
generated dynamic standard atmosphere, yielding an approximate method detection limit (MDL) of 2 μg m–3 (0.25 ppbv). This concentration is one twentieth of the Occupational Safety and Health Administration (OSHA) 8-hour time-weighted
average (TWA) exposure limit. The sampler with the PDMS–DVB-DBA coating was found to be stable and retains the required amount
of DBA for at least 10 days, an important feature for sampling systems with potential in-situ applications.
Received: 2 October 2000 / Revised: 4 December 2000 / Accepted: 6 December 2000 相似文献
6.
A. Molina-Díaz A. Ruiz-Medina M. L. Fernández-de Córdova 《Fresenius' Journal of Analytical Chemistry》1999,363(1):92-97
A continuous flow-through solid phase spectrophotometric system was developed for the determination of ascorbic acid based
on the measurement of its intrinsic absorbance in the UV region when retained on a 1 mm Sephadex QAE A-25 anion exchanger
gel layer which is placed into an appropriate quartz flow-through cell, the absorbance exhibited by this solid phase being
monitored at 267 nm. A monochannel manifold was used, the sample (300, 600 or 1000 μL) being injected into the carrier solution
(acetate buffer). This solution also elutes the analyte after developing the analytical signal, and regenerates the resin
layer which, therefore, remains ready for the next sample. The linear dynamic range and other analytical parameters vary according
to the sample volume injected. Three calibration lines were established for 300, 600 and 1000 μL sample volume, which ranged
from 1.0 to 20.0, 0.5 to 10.0 and 0.2 to 6.0 μg mL–1, respectively. The detection limits were 0.04 (300 μL), 0.03 (600 μL) and 0.02 μg mL–1 (1000 μL), the sampling rates 28, 24 and 21 h–1, and the RSDs (n = 10) 0.87%, 1.08% and 0.90%, respectively. The amount of ascorbic acid in various samples (pharmaceuticals, sweets and urine)
were successfully determined with this method.
Received: 28 April 1998 / Revised: 3 June 1998 / Accepted: 30 June 1998 相似文献
7.
A. Molina-Díaz A. Ruiz-Medina M. L. Fernández-de Córdova 《Analytical and bioanalytical chemistry》1999,363(1):92-97
A continuous flow-through solid phase spectrophotometric system was developed for the determination of ascorbic acid based
on the measurement of its intrinsic absorbance in the UV region when retained on a 1 mm Sephadex QAE A-25 anion exchanger
gel layer which is placed into an appropriate quartz flow-through cell, the absorbance exhibited by this solid phase being
monitored at 267 nm. A monochannel manifold was used, the sample (300, 600 or 1000 μL) being injected into the carrier solution
(acetate buffer). This solution also elutes the analyte after developing the analytical signal, and regenerates the resin
layer which, therefore, remains ready for the next sample. The linear dynamic range and other analytical parameters vary according
to the sample volume injected. Three calibration lines were established for 300, 600 and 1000 μL sample volume, which ranged
from 1.0 to 20.0, 0.5 to 10.0 and 0.2 to 6.0 μg mL–1, respectively. The detection limits were 0.04 (300 μL), 0.03 (600 μL) and 0.02 μg mL–1 (1000 μL), the sampling rates 28, 24 and 21 h–1, and the RSDs (n = 10) 0.87%, 1.08% and 0.90%, respectively. The amount of ascorbic acid in various samples (pharmaceuticals, sweets and urine)
were successfully determined with this method.
Received: 28 April 1998 / Revised: 3 June 1998 / Accepted: 30 June 1998 相似文献
8.
Helvécio C. Menezes Leiliane C. A. Amorim Zenilda L. Cardeal 《Analytical and bioanalytical chemistry》2009,395(8):2583-2589
Benzene is classified as a Group I carcinogen by the International Agency for Research on Cancer (IARC). The risk assessment
for benzene can be performed by monitoring environmental and occupational air, as well as biological monitoring through biomarkers.
The present work developed and validated methods for benzene analysis by GC/MS using SPME as the sampling technique for ambient
air and breath. The results of the analysis of air in parks and avenues demonstrated a significant difference, with average
values of 4.05 and 18.26 μg m−3, respectively, for benzene. Sampling of air in the occupational environment furnished an average of 3.41 and 39.81 μg m−3. Moreover, the correlations between ambient air and expired air showed a significant tendency to linearity (R
2 = 0.850 and R
2 = 0.879). The results obtained for two groups of employees (31.91 and 72.62 μg m−3) presented the same trend as that from the analysis of environmental air. 相似文献
9.
Danuta Gorlo Bogdan Zygmunt Marta Dudek Anna Jaszek Michał Pilarczyk J. Namieśnik 《Analytical and bioanalytical chemistry》1999,363(7):696-699
Practical application of Solid-Phase Microextraction (SPME) for the assessment of the quality of indoor air is presented.
SPME was used to sample selected organic pollutants (carbon tetrachloride, benzene, toluene, chlorobenzene, p-xylene and n-decane). An SPME fiber was coated with a 100 μm film of polydimethylsiloxane. The analytes extracted were analysed with a
gas chromatograph directly coupled with a mass spectrometer (GC-MS). The method was used to assess the indoor air quality
in a few selected flats. The concentrations ranged from below detection limits to 6.9 mg/m3 for benzene depending on the flat; they were relatively high for newly built or freshly renovated flats.
Received: 14 July 1998 / Revised: 17 November 1998 / Accepted: 21 November 1998 相似文献
10.
D. Bohrer P. C. do Nascimento S. Garcia Pomblum E. Seibert L. Machado de Carvalho 《Fresenius' Journal of Analytical Chemistry》1998,361(8):780-783
A method for the determination of cyanide in blood plasma by differential pulse polarography (DPP) is described without a
drastic acidification of the sample. Cyanide was determined as tetracyanonickelate(II)-anion complex after a microwave-acid
assisted cleanup and a selective complex extraction in a polyethylene methylene blue (PE-MB) impregnated column. The cyano
complex was eluted from the column with water/acetonitrile and determined by pulse-polarography at –380 mV (Ag/AgCl). The
linear range of calibration was obtained from 1.2 to 9.6 μg of cyanide with r = 0.99 and RSD = 9% of 1.2 μg of cyanide. A
detection limit of 40 μg L–1 was calculated and the recoveries of cyanide from spiked samples were about 80%. This method was compared with the classical
pyridine-pyrazolone method.
Received: 3 September 1997 / Revised: 21 January 1998 / Accepted: 24 January 1998 相似文献
11.
Manliang Feng Guofang Zhang Zhujun Zhang 《Fresenius' Journal of Analytical Chemistry》1999,363(3):320-322
Chemiluminescence was observed by mixing acidic potassium permanganate solution with pyruvate in the presence of quinine.
A new simplified method for pyruvate determination based on this phenomenon was established. The chemiluminescence intensity
is a linear function of the concentration of pyruvate in the range of 2 × 10–6 to 1 × 10–3 g/mL with a detection limit of 0.8 μg/mL and a relative standard deviation of less than 2.3%. The method has been successfully
used to determine pyruvate in serum.
Received: 3 April 1998 / Revised: 20 July 1998 / Accepted: 17 September 1998 相似文献
12.
J. Begerow E. Jermann T. Keles U. Ranft L. Dunemann 《Fresenius' Journal of Analytical Chemistry》1995,351(6):549-554
A sensitive and reliable method is described for the determination of aromatic and chlorinated hydrocarbons (benzene, toluene, o-, m-, p-xylene, trichloromethane, trichloroethane, trichloroethene and tetrachloroethene) in indoor and outdoor air at environmental concentration levels. The procedure can be easily extended to other VOCs. Using passive samplers the VOCs have been adsorbed onto charcoal during a four-week sampling period and subsequently desorbed with carbon disulfide. After injection with a cold split-splitless multi-injector the VOCs have been separated by capillary gas chromatography. Quantification has been achieved using an electron capture detector (ECD) and a flame ionization detector (FID) switched in series. A limit of about 1 g/m3 for aromatic hydrocarbons and of about 0.01 g/m3 for chlorinated hydrocarbons has been obtained. The procedure has been successfully applied in the framework of a field study to measure indoor and outdoor air concentrations in Essen and Borken, two differently polluted areas of Northrhine-Westphalia. 相似文献
13.
Tomás Pérez-Ruiz Carmen Martínez-Lozano Virginia Tomás Antonio Sanz Jesús Martín 《Fresenius' Journal of Analytical Chemistry》1998,362(4):399-403
A flow-injection configuration is proposed for the fluorimetric determination of ethylenethiourea. The procedure is based
on the inhibitory effect of ethylenethiourea on the oxidation of thiamine to thiochrome by mercury(II). A linear calibration
graph was obtained between 0.1 and 2.0 μg mL–1, with a sampling rate of 40 samples per hour and a relative standard deviation of about 1.11%. The usefulness of the method
was tested for the determination of ethylenethiourea residues in water, milk, potatoes, pear, grape and apple.
Received: 26 January 1998 / Revised: 6 April 1998 / Accepted: 9 April 1998 相似文献
14.
Tomás Pérez-Ruiz Carmen Martínez-Lozano Virginia Tomás Antonio Sanz Jesús Martín 《Analytical and bioanalytical chemistry》1998,362(4):399-403
A flow-injection configuration is proposed for the fluorimetric determination of ethylenethiourea. The procedure is based
on the inhibitory effect of ethylenethiourea on the oxidation of thiamine to thiochrome by mercury(II). A linear calibration
graph was obtained between 0.1 and 2.0 μg mL–1, with a sampling rate of 40 samples per hour and a relative standard deviation of about 1.11%. The usefulness of the method
was tested for the determination of ethylenethiourea residues in water, milk, potatoes, pear, grape and apple.
Received: 26 January 1998 / Revised: 6 April 1998 / Accepted: 9 April 1998 相似文献
15.
R. Binetti S. Di Marzio P. Di Prospero L. Gramiccioni G. Viviano G. Ziemacki 《Chromatographia》1986,21(12):701-704
Summary A simple and accurate headspace-GC method is described to determine the amount of ethylene oxide which has been collected
from air using adsorption tubes containing activated charcoal and a relatively safe desorbing agent (N,N-dimethyl acetamide).
The detection limit is 40μg/m3. 相似文献
16.
Johanna Tollbäck Sindra Isetun Anders Colmsjö Ulrika Nilsson 《Analytical and bioanalytical chemistry》2010,396(2):839-844
Methodology for time-weighted average (TWA) air measurements of semivolatile organophosphate triesters, widely used flame-retardants
and plasticizers, and common indoor pollutants is presented. Dynamic non-equilibrium solid-phase microextraction (SPME) for
air sampling, in combination with GC/PICI and ion trap tandem MS, yields a fast, almost solvent-free method with low detection
limits. Methanol was used as reagent gas for PICI, yielding stable protonated molecules and few fragments. A field sampler,
in which a pumped airflow over three polydimethylsiloxane (PDMS) 100-μm fibers in series was applied, was constructed, evaluated,
and used for the measurements. The method LODs were in the range 2–26 ng m−3 for a sampling period of 2 h. The uptake on the SPME fibers was shown to be about five times faster for triphenyl phosphate
compared to the other investigated organophosphate esters, most likely due to more lipophilic properties of the aromatic compound.
The boundary layer for triphenyl phosphate when using a 100-μm PDMS sorbent was determined to 0.08 mm at a linear air velocity
of 34 cm s−1. Five different organophosphate triesters were detected in air from a laboratory and a lecture hall, at concentrations ranging
from 7 ng m−3 up to 2.8 μg m−3. 相似文献
17.
Annibaldi A Truzzi C Illuminati S Bassotti E Scarponi G 《Analytical and bioanalytical chemistry》2007,387(3):977-998
Eight PM10 aerosol samples were collected in the vicinity of the “Mario Zucchelli” Italian Antarctic Station (formerly Terra
Nova Bay Station) during the 2000–2001 austral summer using a high-volume sampler and precleaned cellulose filters. The aerosol
mass was determined by differential weighing of filters carried out in a clean chemistry laboratory under controlled temperature
and humidity. A two-step sequential extraction procedure was used to separate the water-soluble and the insoluble (dilute-HCl-extractable)
fractions. Cd, Pb and Cu were determined in the two fractions using an ultrasensitive square wave anodic stripping voltammetric
(SWASV) procedure set up for and applied to aerosol samples for the first time. Total extractable metals showed maxima at
midsummer for Cd and Pb and a less clear trend for Cu. In particular, particulate metal concentrations ranged as follows:
Cd 0.84–9.2 μg g−1 (average 4.7 μg g−1), Pb 13.2–81 μg g−1 (average 33 μg g−1), Cu 126–628 μg g−1 (average 378 μg g−1). In terms of atmospheric concentration, the values were: Cd 0.55–6.3 pg m−3 (average 3.4 pg m−3), Pb 8.7–48 pg m−3 (average 24 pg m−3), Cu 75–365 pg m−3 (average 266 pg m−3). At the beginning of the season the three metals appear widely distributed in the insoluble (HCl-extractable) fraction (higher
proportions for Cd and Pb, 90–100%, and lower for Cu, 70–90%) with maxima in the second half of December. The soluble fraction
then increases, and at the end of the season Cd and Pb are approximately equidistributed between the two fractions, while
for Cu the soluble fraction reaches its maximum level of 36%. Practically negligible contributions are estimated for crustal
and sea-spray sources. Low but significant volcanic contributions are estimated for Cd and Pb (∼10% and ∼5%, respectively),
while there is an evident although not quantified marine biogenic source, at least for Cd. The estimated natural contributions
(possibly including the marine biogenic source) cannot account for the high fractions of the metal contents, particularly
for Pb and Cu, and this suggests that pollution from long-range transport is the dominant source.
Figure Aerosol sampling in Antarctica 相似文献
18.
M. C. Yebra M. F. Enríquez A. García A. Moreno-Cid 《Analytical and bioanalytical chemistry》2001,370(1):64-68
A minicolumn packed with poly(aminophosphonic acid) chelating resin incorporated in an on-line preconcentration system for
flame atomic-absorption spectrometry was used to determine ultratrace amounts of lead in mussel samples at μg L–1 level. The preconcentrated lead was eluted with hydrochloric acid and injected directly into the nebulizer for atomization
in an air-acetylene flame for measurement. The performance characteristics of the determination of lead were: preconcentration
factor 26.8 for 1 min preconcentration time, detection limit (3σ) in the sample digest was 0.25 μg g–1 (dry weight) for a sample volume of 3.5 mL and 0.2 g sample (preconcentration time 1 min), precision (RSD) 2.3% for 25 μg
L–1 and 2.0% for 50 μg L–1. The sampling frequency was 45 h–1. The method was highly tolerant of interferences, and the results obtained for the determination of lead in a reference material
testify to the applicability of the proposed procedure to the determination of lead at ultratrace level in biological materials
such as mussel samples.
Received: 1 November 2000 / Revised: 8 January 2001/ Accepted: 11 January 2001 相似文献
19.
Y. Jiang N. Lu Feng Yu Qing Li Hongding Xu 《Analytical and bioanalytical chemistry》1999,364(8):786-787
A method for sampling and determination of hydrogen cyanide in cigarette smoke is described. Cigarette smoke is filtered
through a glass fiber filter paper, and only gaseous compounds, such as hydrogen cyanide, are collected in a dilute sodium
hydroxide solution. The cyanide is determined spectrophotometrically at 550 nm by the isonicotinic acid–pyrazolone method.
Maximum absorbance is achieved within 10 min at room temperature, and remains constant for about 20 min. Beer’s law is obeyed
in the range 0.04∼0.80 μg mL–1 cyanide, with a molar absorptivity of 3.48 × 104 L mol–1 cm–1.
Received: 30 November 1998 / Revised: 21 April 1999 / Accepted: 30 April 1999 相似文献
20.
Y. Jiang N. Lu Feng Yu Qing Li Hongding Xu 《Fresenius' Journal of Analytical Chemistry》1999,364(8):786-787
A method for sampling and determination of hydrogen cyanide in cigarette smoke is described. Cigarette smoke is filtered
through a glass fiber filter paper, and only gaseous compounds, such as hydrogen cyanide, are collected in a dilute sodium
hydroxide solution. The cyanide is determined spectrophotometrically at 550 nm by the isonicotinic acid–pyrazolone method.
Maximum absorbance is achieved within 10 min at room temperature, and remains constant for about 20 min. Beer’s law is obeyed
in the range 0.04∼0.80 μg mL–1 cyanide, with a molar absorptivity of 3.48 × 104 L mol–1 cm–1.
Received: 30 November 1998 / Revised: 21 April 1999 / Accepted: 30 April 1999 相似文献