共查询到20条相似文献,搜索用时 125 毫秒
1.
SPME in environmental analysis 总被引:1,自引:0,他引:1
Recent advances in the use of solid-phase microextraction (SPME) in environmental analysis, including fiber coatings, derivatization
techniques, and in-tube SPME, are reviewed in this article. Several calibration methods for SPME, including traditional calibration
methods, the equilibrium extraction method, the exhaustive extraction method, and several diffusion-based calibration methods,
are presented. Recent developed SPME devices for on-site sampling and several applications of SPME in environmental analysis
are also introduced.
相似文献
2.
Polo M Garcia-Jares C Llompart M Cela R 《Analytical and bioanalytical chemistry》2007,388(8):1789-1798
A solid-phase microextraction method (SPME) followed by gas chromatography with micro electron capture detection for determining
trace levels of nitro musk fragrances in residual waters was optimized. Four nitro musks, musk xylene, musk moskene, musk
tibetene and musk ketone, were selected for the optimization of the method. Factors affecting the extraction process were
studied using a multivariate approach. Two extraction modes (direct SPME and headspace SPME) were tried at different extraction
temperatures using two fiber coatings [Carboxen–polydimethylsiloxane (CAR/PDMS) and polydimethylsiloxane–divinylbenzene (PDMS/DVB)]
selected among five commercial tested fibers. Sample agitation and the salting-out effect were also factors studied. The main
effects and interactions between the factors were studied for all the target compounds. An extraction temperature of 100 °C
and sampling the headspace over the sample, using either CAR/PDMS or PDMS/DVB as fiber coatings, were found to be the experimental
conditions that led to a more effective extraction. High sensitivity, with detection limits in the low nanogram per liter
range, and good linearity and repeatability were achieved for all nitro musks. Since the method proposed performed well for
real samples, it was applied to different water samples, including wastewater and sewage, in which some of the target compounds
(musk xylene and musk ketone) were detected and quantified.
Figure Stardardized Pareto charts for the main effects and interactions 相似文献
3.
A novel headspace solid-phase microextraction method for the exact determination of organochlorine pesticides in environmental soil samples 总被引:2,自引:0,他引:2
Zhao R Wang X Yuan J Jiang T Fu S Xu X 《Analytical and bioanalytical chemistry》2006,384(7-8):1584-1589
A novel method of determining organochlorine pesticides (OCPs) is described. It is based on solid-phase microextraction (SPME) and gas chromatography–electron capture detection. During the development of the method, soil samples were prepared, spiked with standard solution, and then aged for some time. Extraction conditions such as the extraction time, the NaCl content, the volume of water, the extraction temperature and the desorption time were investigated and optimized. The limits of detection obtained using the method ranged from 0.10 to 0.51 ng g−1, and relative standard deviations were lower than 10% for most organochlorine pesticides. Real soil samples were successfully analyzed using the proposed method. The results from the method developed here were in good agreement with those obtained using ultrasonic extraction. The result demonstrates that aging soils spiked with standard solution is an important method development step, because the soil samples obtained using this approach are more like real soils than those obtained when aging is not used.
相似文献
4.
Stir bar sorptive extraction in combination with thermal desorption coupled online to capillary gas chromatography–mass spectrometry
was applied to investigate volatile and semivolatile fractions in two waste leachate samples: old and fresh ones. The present
study helps to improve our knowledge of waste leachate organic composition. The aim is to then make use of this knowledge
afterwards in order to generate more reliable and specific treatment processes for waste leachates and thus to respect the
environmental statute law regarding their rejection. The volatile and semivolatile compounds appeared to be mainly anthropogenic
in origin. Moreover, lactic acid and cyclic octaatomic sulfur could potentially be used as microbiological activity indicators,
since they occur during organic matter degradation processes within waste leachates.
Figure TDU-CGC-MS analytical equipment 相似文献
5.
Recent developments in solid-phase microextraction 总被引:2,自引:0,他引:2
Risticevic S Niri VH Vuckovic D Pawliszyn J 《Analytical and bioanalytical chemistry》2009,393(3):781-795
The main objective of this review is to describe the recent developments in solid-phase microextraction technology in food,
environmental and bioanalytical chemistry applications. We briefly introduce the historical perspective on the very early
work associated with the development of theoretical principles of SPME, but particular emphasis is placed on the more recent
developments in the area of automation, high-throughput analysis, SPME method optimization approaches and construction of
new SPME devices and their applications. The area of SPME automation for both GC and LC applications is particularly addressed
in this review, as the most recent developments in this field have allowed the use of this technology for high-throughput
applications. The development of new autosamplers with SPME compatibility and new-generation metal fibre assemblies has enhanced
sample throughput for SPME-GC applications, the latter being attributed to the possibility of using the same fibre for several
hundred extraction/injection cycles. For LC applications, high-throughput analysis (>1,000 samples per day) can be achieved
for the first time with a multi-SPME autosampler which uses multi-well plate technology and allows SPME sample preparation
of up to 96 samples in parallel. The development and evolution of new SPME devices such as needle trap, thin-film microextraction
and cold-fibre headspace SPME have offered significant improvements in performance characteristics compared with the conventional
fibre-SPME arrangement.
Figure Photo of a high-throughput multi-fibre SPME PAS autosampler 相似文献
6.
Acetone plays an important role in the chemistry of both the atmosphere and the ocean, due to its potential effect on the
tropospheric HOx (= HO + HO2) budget, as well as its environmental and health effects. We discuss the development of a mobile, sensitive, selective, economical
and facile method for the determination of acetone in seawater. The method consists of derivatizing acetone to its pentafluorobenzyl
oxime using 1,2,3,4,5-pentafluorobenzylhydroxylamine (PFBHA), followed by solid-phase microextraction (SPME) and analysis
by gas chromatography/mass spectrometry (GC/MS). A detection limit of 3.0 nM was achieved. The buffering capacity of seawater
imposes challenges in using the method’s optimum pH (3.7) on seawater samples, requiring calibration standards to be made
in buffered salt water and the acidification of seawater samples and standards prior to extraction. We employed the technique
for analysis of selected surface seawater samples taken on the Nordic seas during the ARK-XX/1 cruise (R.V. Polarstern). An upper limit of 5.5–9.6 nM was observed for acetone in these waters, the first acetone measurements reported for far
North Atlantic and Arctic waters.
Simplified schematic of transformations of organic compounds at the atmosphere–ocean interface 相似文献
7.
Cosmetic preparations typically consist of mixtures of various compounds of natural origin or their derivatives. Their analysis
is made rather difficult by their usually high complexity and is utterly impossible with a single analytical method; also,
there is usually little to be gained by determining every individual component of the mixture. Rather, analyses are aimed
at ensuring a proper balance between the contents of each component and thus require the use of methods capable of delivering
global information. The combined use of near-infrared (NIR) spectroscopy and multivariate spectral processing chemometric
techniques has enabled the development of effective methods for establishing the composition of complex samples with acceptable
levels of analytical properties, such as accuracy, precision and throughput. In this work, we developed partial least squares
calibration models for the determination of each component in a cosmetic mixture, and global indices (viz. the hydroxyl value),
simply from the NIR spectrum of the sample. The models thus obtained are accurate enough for use in quality control analyses
of cosmetic preparations and provide an effective alternative to existing conventional global methods.
Experimental setup for measurement 相似文献
8.
Audrey N. Martin George R. Farquar A. Daniel Jones Matthias Frank 《Analytical and bioanalytical chemistry》2010,396(2):739-750
Solid-phase microextraction (SPME) was applied, in conjunction with gas chromatography–mass spectrometry, to the analysis
of volatile organic compounds (VOCs) in human breath samples without requiring exhaled breath condensate collection. A new
procedure, exhaled breath vapor (EBV) collection, involving the active sampling and preconcentration of a breath sample with
a SPME fiber fitted inside a modified commercial breath-collection device, the RTube™, is described. Immediately after sample
collection, compounds are desorbed from the SPME fiber at 250 °C in the GC-MS injector. Experiments were performed using EBV
collected at −80 °C and at room temperature, and the results compared to the traditional method of collecting exhaled breath
condensate at −80 °C followed by passive SPME sampling of the collected condensate. Methods are compared in terms of portability,
ease-of-use, speed of analysis, and detection limits. The need for a clean air supply for the study subjects is demonstrated
using several localized sources of VOC contaminants including nail polish, lemonade, and gasoline. Various simple methods
to supply clean inhaled air to a subject are presented. Chemical exposures are used to demonstrate the importance of providing
cleaned air (organic vapor respirator) or an external air source (tubing stretched to a separate room). These techniques allow
for facile data interpretation by minimizing background contaminants. It is demonstrated herein that this active SPME breath-sampling
device provides advantages in the forms of faster sample collection and data analysis, apparatus portability and avoidance
of power or cooling requirements, and performance for sample collection in a contaminated environment.
相似文献
9.
Volatile organic compounds (VOCs) and odors in cattle rumen gas have been characterized by in-vivo headspace sampling by solid-phase
microextraction (SPME) and analysis by gas chromatography–mass spectrometry–olfactometry (GC–MS–O). A novel device enabling
headspace SPME (HS-SPME) sampling through a cannula was designed, refined, and used to collect rumen gas samples from steers.
A Carboxen–polydimethylsiloxane (PDMS) fiber (85 μm) was used for SPME sampling. Fifty VOCs from ten chemical groups were
identified in the rumen headspace. The VOCs identified had a wide range of molecular weight (MW) (34 to 184), boiling point
(−63.3 to 292 °C), vapor pressure (1.05 × 10−5 to 1.17 × 102 Pa), and water solubility (0.66 to 1 × 106 mg L−1). Twenty-two of the compounds have a published odor detection thresholds (ODT) of less than 1 ppm. More than half of the
compounds identified are reactive and have an estimated atmospheric lifetime of <24 h. The amounts of VFAs, sulfide compounds,
phenolic compounds, and skatole, and the odor intensity of VFAs and sulfide compounds in the rumen gas were all higher after
feeding than before feeding. These results indicate that rumen gases can be an important potential source of aerial emissions
of reactive VOCs and odor. In-vivo sampling by SPME then GC–MS–O analysis can be a useful tool for qualitative characterization
of rumen gases, digestion, and its relationship to odor and VOC formation.
Figure Modified cannula for rumen gas sampling with SPME 相似文献
10.
Karin Hoffmann-Sommergruber E. N. Clare Mills 《Analytical and bioanalytical chemistry》2009,395(1):25-35
A large number of food allergens able to induce allergic symptoms in predisposed individuals, including severe, even life-threatening
reactions, have been identified and characterized. However, proteins able to cause such IgE-mediated reactions can be assigned
to only a limited number of protein families. Detailed knowledge about the characteristics of food allergens, their 3D structures,
biological activity and stability, will help to improve diagnosis of food allergy, avoid unnecessary exclusion diets and assess
the risk of cross-reactive allergies to other food sources. This review is dedicated to summarizing current knowledge about
the most important food allergen protein families and to presenting data from the EuroPrevall allergen library, a proof-of-concept
collection of highly purified, characterized and authenticated food allergens from animal and plant food sources to facilitate
improved diagnosis of food allergies.
Relevant food allergen sources 相似文献
11.
Eranda Wanigasekara Sirantha Perera Jeffrey A. Crank Leonard Sidisky Robert Shirey Alain Berthod Daniel W. Armstrong 《Analytical and bioanalytical chemistry》2010,396(1):511-524
Four new ionic liquids (IL) were prepared and bonded onto 5-μm silica particles for use as adsorbent in solid-phase microextraction
(SPME). Two ILs contained styrene units that allowed for polymerization and higher carbon content of the bonded silica particles.
Two polymeric ILs differing by their anion were used to prepare two SPME fibers that were used in both headspace and immersion
extractions and compared to commercial fibers. In both sets of experiments, ethyl acetate was used as an internal standard
to take into account adsorbent volume differences between the fibers. The polymeric IL fibers are very efficient in headspace
SPME for short-chain alcohols. Immersion SPME also can be used with the IL fibers for short-chain alcohols as well as for
polar and basic amines that can be extracted at pH 11 without damage to the IL-bonded silica particles. The sensitivities
of the two IL fibers differing by the anion were similar. Their efficacy compares favorably to that of commercial fibers for
polar analytes. The mechanical strength and durability of the polymeric IL fibers were excellent.
相似文献
12.
Pérez Pavón JL García Pinto C Guerrero Peña A Moreno Cordero B 《Analytical and bioanalytical chemistry》2008,391(2):599-607
In the present work we report the results obtained with a methodology based on direct coupling of a headspace generator to
a mass spectrometer for the identification of different types of petroleum crudes in polluted soils. With no prior treatment,
the samples are subjected to the headspace generation process and the volatiles generated are introduced directly into the
mass spectrometer, thereby obtaining a fingerprint of volatiles in the sample analysed. The mass spectrum corresponding to
the mass/charge ratios (m/z) contains the information related to the composition of the headspace and is used as the analytical signal for the characterization
of the samples. The signals obtained for the different samples were treated by chemometric techniques to obtain the desired
information. The main advantage of the proposed methodology is that no prior chromatographic separation and no sample manipulation
are required. The method is rapid, simple and, in view of the results, highly promising for the implementation of a new approach
for oil spill identification in soils.
Figure PCA score plots illustrate clear discrimination of types of crude oil in polluted soil samples (e.g. results are shown for
vertisol) 相似文献
13.
Aguinaga N Campillo N Viñas P Hernández-Córdoba M 《Analytical and bioanalytical chemistry》2008,391(4):1419-1424
This paper describes a headspace solid-phase microextraction (HS-SPME) procedure coupled to gas chromatography with mass spectrometric
detection (GC–MS) for the determination of eight PAHs in aquatic species. The influence of various parameters on the PAH extraction
efficiency was carefully examined. At 75 °C and for an extraction time of 60 min, a polydimethylsiloxane–divinylbenzene (PDMS/DVB)
fiber coating was found to be most suitable. Under the optimized conditions, detection limits ranged from 8 to 450 pg g−1, depending on the compound and the sample matrix. The repeatability varied between 7 and 15% (RSD). Accuracy was tested using
the NIST SRM 1974b reference material. The method was successfully applied to different samples, and the studied PAHs were
detected in several of the samples.
Figure Headspace SPME sampling followed by GC–MS facilitates routine monitoring of PAHs in aquatic species 相似文献
14.
A novel microextraction method is introduced based on dispersive liquid–liquid microextraction (DLLME) in which an in situ
metathesis reaction forms a water-immiscible ionic liquid (IL) that preconcentrates aromatic compounds from water followed
by separation using high-performance liquid chromatography. The simultaneous extraction and metathesis reaction forming the
IL-based extraction phase greatly decreases the extraction time as well as provides higher enrichment factors compared to
traditional IL DLLME and direct immersion single-drop microextraction methods. The effects of various experimental parameters
including type of extraction solvent, extraction and centrifugation times, volume of the sample solution, extraction IL and
exchanging reagent, and addition of organic solvent and salt were investigated and optimized for the extraction of 13 aromatic
compounds. The limits of detection for seven polycyclic aromatic hydrocarbons varied from 0.02 to 0.3 μg L−1. The method reproducibility produced relative standard deviation values ranging from 3.7% to 6.9%. Four real water samples
including tap water, well water, creek water, and river water were analyzed and yielded recoveries ranging from 84% to 115%.
相似文献
15.
Fernández-Alvarez M Lores M Llompart M García-Jares C Cela R 《Analytical and bioanalytical chemistry》2007,388(5-6):1235-1247
In the present study, solid-phase microextraction in photochemical studies was used to investigate UV light induced photodegradation
of five pyrethroids (empenthrin, transfluthrin, allethrin, phenothrin and cyphenothrin) and a synergist (piperonyl butoxide),
which are common ingredients of household insecticides. Gas chromatography coupled with mass spectrometry was used to separate
and tentatively identify the parent compounds and their corresponding photoproducts generated in the same polydimethylsiloxane
fibre. Kinetics curves were obtained and apparent first-order rate constants and half-lives were estimated. Twenty-six photoproducts
were tentatively identified and photodegradation pathways for the compounds investigated were proposed. It is a matter of
some concern that three of the photoproducts identified [(3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylic acid, 3-phenoxybenzaldehyde
and (3-phenoxyphenyl)methanol] have been reported to be endocrine disruptors. There is no record of previous studies of cyphenothrin
and empenthrin photodegradation, and therefore the present study represents the first attempt to elucidate the photochemical
behaviour of these compounds.
Figure Photo-SPME for Pyrethroids 相似文献
16.
Céspedes R Lacorte S Ginebreda A Barceló D 《Analytical and bioanalytical chemistry》2006,385(6):992-1000
This study presents a quantitative estimation of the analysis and fate of several emerging pollutants, some of them endocrine-disrupting
compounds, in surface water samples collected at several locations along the Ter River and two of its tributaries. Influent
and effluent waters and particulate matter from five sewage treatment plants (STP) that discharge into these rivers were also
studied. The target compounds analyzed were: nonylphenol ethoxylates (NPEO), nonylphenol (NP), octylphenol (OP), bisphenol
A (BPA), phthalates, alcohol ethoxylates (AEO) and benzothiazoles. Chemical analysis by liquid chromatography–mass spectrometry
using an electrospray interface (LC–ESI–MS) revealed the presence of low amounts (between 0.06 and 17.5 μg L−1) of the target compounds NPE1+2O and NP, which were detected in 100% and 84% of the samples respectively. Maximum concentrations occurred in the STPs associated
with the municipalities of Vic and Girona. From the fate and behavior data obtained for the various compounds analyzed in
the STP influent and effluent, we can conclude that the STPs are effective at removing large amounts (more than 70%) of the
compounds studied from the water.
相似文献
17.
Solid-phase microextraction (SPME) is a convenient and efficient sampling technique recently applied to indoor air analysis.
We propose here a theoretical model of the adsorption kinetics of toluene on SPME fibre under static extraction conditions.
We discuss the effects of sampling volume and initial concentration of analyte on the adsorption kinetics. This model is used
to estimate the limits of detection taking into account operating conditions and to calculate theoretical calibration curves.
Results of comparison with experimental data are encouraging: only 11% difference for calibration curves and 30% for the estimation
of the limit of detection. On the basis of this kinetics model, the solid concentration gradient in the Carboxen coating was
modelled with Fick’s second law of diffusion in unsteady-state mass-transfer mode. Mass diffusion from the gas sample to the
SPME fibre was also investigated. It was shown that diffusion is the limiting step of the mass-transfer process in the static
mode. Thus, the model developed, allows a better understanding of adsorption on Carboxen fibre and in the future could be
a useful tool for cheap and time-saving development of SPME methods and the estimation of sampling performance.
Figure PDMS/Carboxen SPME fibre (scanning electron microscopy – magnification x 220) 相似文献
18.
19.
Brambilla R Pinto CF Miranda MS dos Santos JH 《Analytical and bioanalytical chemistry》2008,391(7):2673-2681
A series of octadecylsilane-modified silicas were prepared by sol-gel and grafting methods. Carbon contents and octadecyl
chain conformations were shown to depend on the preparative route. Grafting engenders a low carbon content and a liquid-like
chain conformation, while the sol-gel method affords a much higher carbon content and a crystalline conformation. The relationships
between the toluene adsorption of the hybrid silicas and their chain conformations, their carbon contents and their textural
characteristics are discussed. These sorbents, when used in combination with ultraviolet diffuse reflectance spectroscopy
(UV DRS), can be employed as a rapid screening method for detection of aromatic compounds in water and air environmental matrices.
Figure Octadecylsilane-modified silicas in the adsorption of toluene 相似文献
20.
Salgado-Petinal C Garcia-Chao M Llompart M Garcia-Jares C Cela R 《Analytical and bioanalytical chemistry》2006,385(3):637-644
A headspace solid-phase microextraction gas chromatography coupled with tandem mass spectrometry (HSSPME-GC-MS-MS) methodology for determination of brominated flame retardants in sediment and soil samples is presented. To the best of our knowledge, this is the first time that SPME has been applied to analyze polybrominated biphenyls (PBBs) and polybrominated diphenyl ethers (PBDEs) in environmental solid samples. Analyses were performed using 0.5-g solid samples moisturized with 2 mL water, employing a polydimethylsiloxane (PDMS) fiber coating, exposed to the headspace at 100 °C for 60 min. Several types of environmental solid samples were included in this study and the extraction efficiency was related to the organic matter content of the sample. Calibration was performed using real samples, and the method showed good linearity over a wide concentration range, precision, and afforded quantitative recoveries. The obtained detection limits were in the sub-ng g−1 for all the target analytes in both samples. The proposed procedure was applied to several marine and river sediments and soils, some of which were found to contain PBDEs at concentrations in the ng g−1 level; BDE-47, BDE-100, and BDE-99 were the major congeners detected. The proposed method constitutes a rapid and low-cost alternative for the analysis of the target brominated flame retardants in environmental solid samples, since the clean-up steps, fractionation, and preconcentration of extracts inherent to the classical multi-step solvent extraction procedures are avoided.
相似文献