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1.
A confirmatory and quantitative method based on liquid chromatography–electrospray ionization tandem mass spectrometry (LC-ESI/MS/MS)
has been developed for simultaneous determination of seven photoinitiator residues: benzophenone, (1-hydroxycyclohexyl)phenylketone
(Irgacure 184), isopropylthioxanthone (ITX), 2-ethylhexyl-(4-dimethylamino)benzoate (EHA or EHDAB), 2-methyl-1-[4-(methylthio)phenyl]-2-(4-morpholinyl)-1-propanone
(Irgacure 907), (2,4,6-trimethylbenzoyl)diphenylphosphine oxide (TPO) and 2-benzyl-2-(dimethylamino)-1-(4-morpholinophenyl)-1-butanone
(Irgacure 369) in packaged milk and related packaging materials. Residues of photoinitiators were extracted from milk using
acetonitrile, and further enriched and purified on HLB solid-phase extraction cartridges prior to being analyzed by LC-ESI/MS/MS
with selected reaction monitoring mode, while photoinitiators in packaging materials were extracted using the same solvent.
Satisfactory recovery (from 80 to 111%), intra- and inter-day precision (below 12%), and low limits of quantification (from
0.1 to 5.0 μg kg−1) were evaluated from spiked samples at three concentration levels (5.0, 10.0 and 25.0 μg kg−1 for Irgacure 184 and 2.5, 5.0 and 25.0 μg kg−1 for others). These excellent validation data suggested the possibility of using the LC-ESI/MS/MS method for simultaneous
determination of low-level photoinitiator residues migrating from printed food-packaging materials into milk. The method has
been successfully applied to the analysis of real samples of different fat contents ranging from 8 to 30 g L−1. The photoinitiator residues were revealed to be higher in milk with higher fat content and the most important contaminations
were benzophenone and ITX in concentration ranges of 2.84–18.35 and 0.83–8.87 μg kg−1, respectively. 相似文献
2.
Lina Kantiani Marinella Farré Josep Manuel Grases i Freixiedas Damià Barceló 《Analytical and bioanalytical chemistry》2010,398(3):1195-1205
A fully automated method has been developed for analysis of eighteen antibacterial compounds, including penicillins, cephalosporins
and sulfonamides, in animal feed with limits of quantification in the range 0.25–5.79 μg kg−1. The method is based on pressurized liquid extraction of 3 g homogenized feed with water and online clean-up of 500 μL of
the extract with C18HD cartridges. The purified sample was directly analysed by liquid chromatography–electrospray tandem mass spectrometry (SPE–LC–ESI-MS–MS).
Chromatographic separation was achieved within 10 min by use of a C12 Phenomenex Hydro-RP reversed-phase analytical column and a mobile phase gradient (water + 0.1% formic acid–methanol + 0.1%
formic acid). The method was validated, revealing capability for detection of concentrations as low as 0.09 μg kg−1, decision limits (CCα) and detection capabilities (CCβ) in the range 10–174 μg kg−1 and 22–182 μg kg−1, respectively, and inter-day precision ranging from 0.7 to 8.3%. Recovery, with internal standard correction, was in the
range 93–134% for all analytes. The method was then applied to analysis of fifteen feed samples, nine of which contained at
least one antimicrobial at concentrations between 0.006 and 1.526 mg kg−1. The performance data and results from the method were compared with those from a previous method developed by our group,
using offline SPE, by analyzing the same set of samples by both methods. The online SPE approach resulted in slightly improved
sensitivity, with LODs of 0.09–2.12 μg kg−1 compared with 0.12–3.94 μg kg−1 by the offline approach. In general, better recovery was achieved by use of online purification (for 72% of the analytes)
and the correlation between the two methods was good. The main advantages of the new online method are rapid and automated
sample pre-treatment, and reduction of sample manipulation, enabling high-throughput analysis and highly accurate results.
Because of all these characteristics, the proposed method is applicable and could be deemed necessary within the field of
food control and safety. 相似文献
3.
Liu X Xu J Li Y Dong F Li J Song W Zheng Y 《Analytical and bioanalytical chemistry》2011,399(7):2539-2547
A sensitive and effective method for simultaneous determination of triazolopyrimidine sulfonamide herbicide residues in soil,
water, and wheat was developed using ultra-performance liquid chromatography coupled with tandem mass spectrometry. The four
herbicides (pyroxsulam, flumetsulam, metosulam, and diclosulam) were cleaned up with an off-line C18 SPE cartridge and detected
by tandem mass spectrometry using an electrospray ionization source in positive mode (ESI+). The determination of the target
compounds was achieved in <2.0 min. The limits of detection were below 1 μg kg−1, while the limits of quantification did not exceed 3 μg kg−1 in different matrices. Quantitation was determined from calibration curves of standards containing 0.05–100 μg L−1 with r
2 > 0.997. Recovery studies were conducted at three spiked levels (0.2, 1, and 5 μg kg−1 for water; 5, 10, and 100 μg kg−1 for soil and wheat). The overall average recoveries for this method in water, soil, wheat plants, and seeds at three levels
ranged from 75.4% to 106.0%, with relative standard deviations in the range of 2.1–12.5% (n = 5) for all analytes. 相似文献
4.
Determination of tetracycline residues in soil by pressurized liquid extraction and liquid chromatography tandem mass spectrometry 总被引:2,自引:0,他引:2
Vicente Andreu Pablo Vazquez-Roig Cristina Blasco Yolanda Picó 《Analytical and bioanalytical chemistry》2009,394(5):1329-1339
An optimized extraction and cleanup method for the analysis of chlortetracycline (CTC), doxycycline (DC), oxytetracycline
(OTC) and tetracycline (TC) in soil is presented. Soil extraction in a pressurized liquid extraction system, followed by extract
clean up using solid-phase extraction (SPE) and tetracycline determination by liquid chromatography tandem mass spectrometry
(LC-MS/MS) provided appropriate efficiency and reproducibility. Different dispersing agents and solvents for soil extraction
and several SPE cartridges for cleanup were compared. The best extraction results were obtained using ethylenediamine tetraacetic
acid-treated sand as dispersing agent, and water at 70 °C. The most effective cleanup was obtained using Strata-XTM sorbent in combination with a strong anion exchange cartridge. Recoveries ranged from 71% to 96% and precision, as indicated
by the relative standard deviations, was within the range of 8–15%. The limits of quantification (LOQs) by using LC-MS/MS,
based on signal-to-noise ratio (S/N) of 10, ranged from 1 μg kg−1 for TC to 5 μg kg−1 for CTC. These results pointed out that this technique is appropriate to determine tetracyclines in soils. Analysis of 100
samples taken in the Valencian Community revealed that, in soil, up to 5 μg kg−1 CTC, 15 μg kg−1 OTC, 18 μg kg−1 TC, and 12 μg kg−1 DC could be detected. Detection of the analytes in several samples, which typify great part of the Spanish agricultural soils,
should be outlined as most important result of this study.
Electronic supplementary material The online version of this article (doi: ) contains supplementary material, which is available to authorized users. 相似文献
5.
Clémens S Monperrus M Donard OF Amouroux D Guérin T 《Analytical and bioanalytical chemistry》2011,401(9):2699-2711
Methylmercury (MeHg) and total mercury (THg) in seafood were determined using species-specific isotope dilution analysis and
gas chromatography combined with inductively coupled plasma mass spectrometry. Sample preparation methods (extraction and
derivation step) were evaluated on certified reference materials using isotopically enriched Hg species. Solid–liquid extraction,
derivation by propylation and automated agitation gave excellent accuracy and precision results. Satisfactory figures of merit
for the selected method were obtained in terms of limit of quantification (1.2 μg Hg kg−1 for MeHg and 1.4 μg Hg kg−1 for THg), repeatability (1.3–1.7%), intermediate precision reproducibility (1.5% for MeHg and 2.2% for THg) and trueness
(bias error less than 7%). By means of a recent strategy based on accuracy profiles (β-expectation tolerance intervals), the
selected method was successfully validated in the range of approximately 0.15–5.1 mg kg−1 for MeHg and 0.27–5.2 mg kg−1 for THg. Probability β was set to 95% and the acceptability limits to ±15%. The method was then applied to 62 seafood samples
representative of consumption in the French population. The MeHg concentrations were generally low (1.9–588 μg kg−1), and the percentage of MeHg varied from 28% to 98% in shellfish and from 84% to 97% in fish. For all real samples tested,
methylation and demethylation reactions were not significant, except in one oyster sample. The method presented here could
be used for monitoring food contamination by MeHg and inorganic Hg in the future to more accurately assess human exposure. 相似文献
6.
Zang X Wang J Wang O Wang M Ma J Xi G Wang Z 《Analytical and bioanalytical chemistry》2008,392(4):749-754
A novel method was developed for the determination of captan, folpet, and captafol in apples by dispersive liquid–liquid microextraction
(DLLME) coupled with gas chromatography–electron capture detection (GC–ECD). Some experimental parameters that influence the
extraction efficiency, such as the type and volume of the disperser solvents and extraction solvents, extraction time, and
addition of salt, were studied and optimized to obtain the best extraction results. Under the optimum conditions, high enrichment
factors for the compounds were achieved ranging from 824 to 912. The recoveries of fungicides in apples at spiking levels
of 20.0 μg kg−1 and 70.0 μg kg−1 were 93.0–109.5% and 95.4–107.7%, respectively. The relative standard deviations (RSDs) for the apple samples at 30.0 μg kg−1 of each fungicide were in the range from 3.8 to 4.9%. The limits of detection were between 3.0 and 8.0 μg kg−1. The linearity of the method ranged from 10 to 100 μg kg−1 for the three fungicides, with correlation coefficients (r
2) varying from 0.9982 to 0.9997. The obtained results show that the DLLME combined with GC–ECD can satisfy the requirements
for the determination of fungicides in apple samples.
Figure Dispersive liquid–liquid microextraction (DLLME) coupled with gas chromatography–electron capture detection (GC–ECD) allows
satisfactory determination of fungicides in apple samples 相似文献
7.
The worldwide contamination of winery by-products by mycotoxins may present a serious hazard to human and animal health. Mycotoxins
are secondary metabolites of fungi with possible adverse effects on humans, animals, and crops that result in illnesses and
economic losses. Mycotoxins are under continuous survey in Europe, but the regulatory aspects still need to be set up for
winery by-products, which may be used in animal feed. The aim of this study was to implement a simple but reliable analytical
methodology for ochratoxin A (OTA) quantification in grape pomaces in order to perform a survey of samples from the Douro
Demarcated Region, Portugal. The method involved a unique preparation step, solvent extraction, followed by high-performance
liquid chromatography (HPLC) with fluorescence (FL) detection. A comparative study was performed with two extraction solvents
(ethyl acetate and methanol) as well as using extraction on an immunoaffinity column. The linearity range for OTA analysis
was 0.05–23.5 μg L−1 with a detection limit of 0.05 μg L−1 and a precision (expressed by the coefficient of variation under repeatability conditions) of 0.4–14.7%. The percentage of
recovery was on average 23.5 ± 3.6% (extraction with ethyl acetate) or 70.1 ± 2.5% (extraction with 70% methanol). Accounting
for the recovery factor and the chromatographic detection limit, as well as the preconcentration factor, the limit of detection
in grape pomaces is 0.04 μg kg−1 (ethyl acetate extraction) and 0.33 μg kg−1 (methanol extraction). Samples from 12 out of 13 sites in the Douro Demarcated Region showed OTA presence with concentrations
not exceeding 0.4 μg kg−1. Both developed methods for evaluation of OTA in grape pomace are simple but efficient.
Figure Extraction of ochratoxin A (OTA) from grape pomaces allows simple but efficient quantification of OTA in winery by-products
by HPLC-FL 相似文献
8.
Development and validation of an UPLC-MS/MS method for the determination of ionophoric and synthetic coccidiostats in vegetables 总被引:1,自引:0,他引:1
Broekaert N Van Peteghem C Daeseleire E Sticker D Van Poucke C 《Analytical and bioanalytical chemistry》2011,401(10):3335-3344
In poultry farming, anticoccidial drugs are widely used as feed additives for the prevention and treatment of coccidiosis.
Because coccidiostats and veterinary medicines, in general, are often poorly absorbed, manure from treated animals may contain
high concentrations of these compounds. Experimental studies have shown that the uptake of veterinary medicines by plants
from soil containing contaminated manure may occur. This leads to several questions regarding the impact on the environment,
resistance problems, and public health and allergy issues. This work describes the development of a quantification method
for coccidiostats in vegetables. Vegetables were spiked at 100 μg kg−1 (dry weight) with coccidiostats (monensin, narasin, lasalocid A, salinomycin, diclazuril, and nicarbazin) in order to optimize
the extraction and clean-up. Possible critical factors (e.g., extraction solvent) were statistically examined by linear regression
with the use of Plackett–Burman and full factorial designs. Final extracts were analyzed with ultra-performance liquid chromatography
tandem mass spectrometry operating in multiple-reaction monitoring mode. Both the synthetic and ionophoric coccidiostats could
be determined in a single run with an analysis time of 5 min. The developed method was validated taking into account the requirements
of the Commission Decision 2002/657/EC as a guideline. The method is regarded as applicable for its intended purposes with
quantification limits between 0.30 and 2.98 μg kg−1. This method could be used to establish possible maximum residue limits for coccidiostats in vegetables, as already exist
for eggs, meat, and milk. 相似文献
9.
Li Y Dong F Liu X Xu J Li J Lu C Wang Y Zheng Y 《Analytical and bioanalytical chemistry》2011,400(9):3097-3107
A rapid and simple miniaturized liquid–liquid extraction method has been developed for the determination of topramezone in
soil, corn, wheat, and water samples using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-electrospray
ionization (ESI)/MS/MS). The established method for the extraction and purification procedure was based on liquid–liquid partitioning
into an aqueous solution at a low pH (pH ≈ 2.5), followed by back-partitioning into water at pH > 9. Two precursor, product
ion transitions for topramezone were measured and evaluated to provide the maximum degree of confidence in the results. Under
negative ESI conditions, quantitation was achieved by monitoring the fragment at m/z = 334 and the qualitative fragment at m/z = 318, whereas also collecting the corresponding parent ion at m/z = 362. Chromatographic separation was achieved using gradient elution with a mobile phase consisting of methanol and a 0.01%
aqueous ammonium hydroxide solution. Recovery studies for soil, corn, wheat, and water were conducted at four different topramezone
concentrations (5 or 10, 50, 100, and 1,000 μg kg−1); the overall average recoveries ranged from 79.9% to 98.4% with intra-day relative standard deviations (RSD) of 3.1~8.7%
and inter-day RSD of 4.3~7.5%. Quantitative results were determined from calibration curves of topramezone standards containing
1–500 μg L−1 with an R
2 ≥ 0.9994. Method sensitivities expressed as limits of quantitation were typically 6, 8, 9, and 1 μg kg−1 in soil, corn, wheat, and water, respectively. The results of the method validation confirmed that this proposed method was
convenient and reliable for the determination of topramezone residues in soil, corn, wheat, and water. 相似文献
10.
Berendsen BJ Wegh RS Essers ML Stolker AA Weigel S 《Analytical and bioanalytical chemistry》2012,402(4):1611-1623
A liquid chromatography–tandem mass spectrometry method for the analysis of seven antiviral drugs, zanamivir, ribavirin, oseltamivir,
oseltamivir carboxylate, amantadine, rimantadine and arbidol, in poultry muscle is reported. The antiviral drugs were extracted
from the homogenized poultry muscle sample using methanol. The extract was purified using tandem solid-phase extraction combining
a cation exchange cartridge and a phenylboronic acid cartridge. To prevent excessive matrix effects, the analytes were separated
from the matrix constituents using a column-switch liquid chromatography system combining a reversed-phase and a Hypercarb
analytical column. Detection was carried out using tandem mass spectrometry. The method was fully validated according to 2002/657/EC
[1] and proved to be adequate for quantification and confirmation of zanamivir and ribavirin at 10 μg kg−1, oseltamivir, oseltamivir carboxylate, amantadine and rimantadine at levels below 1.0 μg kg−1 and for qualitative confirmatory analysis of arbidol at levels below 1 μg kg−1. 相似文献
11.
This paper reports a novel approach for the detection, confirmation, and quantification of 15 selected pyrethroid pesticides,
including pyrethins, and two metabolites of dithiocarbamates in foods by ultra-performance liquid chromatography–tandem mass
spectrometry (UPLC–MS–MS). The proposed method makes use of a modified QuEChERS (quick, easy, cheap, effective, rugged, and
safe) procedure that combines isolation of the pesticides and sample cleanup in a single step. Analysis of pyrethroids and
dithiocarbamate metabolites was performed by UPLC–MS–MS operated with electrospray and atmospheric pressure chemical ionization,
respectively. Two specific precursor–product ion transitions were acquired per target compound in multiple reaction monitoring
(MRM) mode. Such acquisition achieved the minimum number of identification points according to European Commission (EC) document
no. SANCO/10684/2009, thus fulfilling the EC point system requirement for identification of contaminants in samples. The method
was validated with a variety of food samples. Calibration curves were linear and covered from 1 to 800 μg kg−1 in the sample for all target compounds. Average recoveries, measured at mass fractions of 10 and 100 μg kg−1 for pyrethroids and 5 and 50 μg kg−1 for dithiocarbamate metabolites, were in the range of 70–120% for all target compounds with relative standard deviations
below 20%. Method limits of quantification (MLOQ) were 10 μg kg−1 and 5 μg kg−1 for pyrethroids and dithiocarbamate metabolites, respectively. The method has been successfully applied to the analysis of
600 food samples in the course of the first Hong Kong total diet study with pyrethroids and metabolites of dithiocarbamates
being the pesticides determined. 相似文献
12.
Horst Fr. Schröder Wilhelm Gebhardt Mario Thevis 《Analytical and bioanalytical chemistry》2010,398(3):1207-1229
Municipal wastewater has been examined for steroids, β2-agonists, stimulants, diuretics, and phosphodiesterase type V inhibitors (PDE type V inhibitors), which are “dual-use-drugs”
applied either as anabolic, doping, and lifestyle drugs or for treatment of diverse diseases. To identify their origin, fitness
centre discharges under suspicion of being point sources and sewage-treatment plant feed and effluents were sampled and concentrations
determined. Sensitive and selective methods for determination and quantification based on solid-phase extraction (SPE) followed
by high-performance liquid chromatography–high resolution mass and tandem mass spectrometry (HPLC–(HR)MS and HPLC–MS–MS) were
developed and established for analysis of these compounds in wastewater and to assess their effect on the environment. The
methods developed enabled quantification at trace concentrations (limit of quantification (LOQ): 5 ng L−1). Of the steroids and stimulants under investigation, testosterone, methyltestosterone, and boldenone or ephedrine, amphetamine,
and MDMA (3,4-methylendioxy-N-methylamphetamine) were observed at up to 5 μg L−1 (ephedrine). Of the β2-agonists salbutamol only, and of the diuretics furosemide and hydrochlorothiazide were confirmed in the extracts. Quite high
concentrations of the PDE type V inhibitors sildenafil, tadalafil, and vardenafil and their metabolites were confirmed in
fitness centre discharges (sildenafil: 1,945 ng L−1) whereas their concentrations in municipal wastewater did not exceed 35 ng L−1. This study identified anabolic and doping drugs in wastewater for the first time. Results obtained from wastewater treatment
plant effluents proved that these “dual-use-drugs”, with the exception of hydrochlorothiazide, were mostly eliminated. 相似文献
13.
L. Giannetti F. Longo F. Buiarelli M. V. Russo B. Neri 《Analytical and bioanalytical chemistry》2010,398(2):1017-1023
A specific, sensitive and robust liquid chromatography tandem mass spectrometry method for determining oxytetracycline, tetracycline,
chlortetracycline and doxycycline in royal jelly and honey samples is presented. Extraction of drug residues was performed
by ammonium acetate buffer as extractant followed by a clean-up with metal chelate affinity chromatography and solid-phase
extraction. Tetracycline analysis was performed using liquid chromatography–electrospray ionisation–tandem mass spectrometry.
The presented method is the first validated for royal jelly and in accordance with the requirements set by Commission Decision
2002/657/EC. Recoveries of the methods, calculated spiking the samples at 5.0, 10.0, 20.0 and 30.0 μg kg−1, were 79% to 90% for honey and 77% to 90% for royal jelly. The intra-day precision (RSD) ranged between 8.1% and 15.0% for
honey and from 9.1% to 16.3% for royal jelly, while inter-day precision values were from 10.2% to 17.6% and from 10.6% to
18.4% respectively for honey and royal jelly. Linearity for the four analytes was calculated from 5.0 to 50.0 μg kg−1. The decision limits (CCα) ranged from 6.2 to 6.4 μg kg−1 and from 6.1 to 6.5 μg kg−1 for honey and royal jelly, respectively. Detection capabilities values (CCβ) ranged between 7.2 and 7.7 μg kg−1 and from 7.3 to 7.9 μg kg−1 respectively for honey and royal jelly. The developed method is currently in use for confirmation of the official control
analysis of honey and royal jelly samples. 相似文献
14.
José Luis Martínez Vidal Antonia Garrido Frenich María de las Nieves Barco Bonilla Roberto Romero-González Juan Antonio Padilla Sánchez 《Analytical and bioanalytical chemistry》2009,395(5):1551-1562
A simple and rapid method based on pressurized liquid extraction has been validated for the simultaneous extraction of polychlorinated
biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) from agricultural soil samples. Effective extraction was carried
out in less than 17 min for all the studied compounds, and good recoveries were obtained for PAHs and PCBs, ranging from 70%
to 112%, when blank samples were spiked at 2.5 μg kg−1, except for naphthalene with recoveries close to 40%. The separation and determination were performed by gas chromatography
coupled to tandem mass spectrometry using a triple quadrupole mass analyzer. The target compounds were detected by electron
impact with selected reaction monitoring, and mass spectrometric conditions were optimized in order to increase selectivity
and sensitivity. The developed method was validated, and matrix-matched calibration was used for quantification purposes.
Repeatability and interday precision ranged from 0.9% to 16.8% and from 1.6% to 22.3%, respectively. Limits of quantification
ranged from 0.07 to 2.50 μg kg−1. The proposed method was applied to the analysis of agricultural soil samples collected from Almeria (Spain), and PAHs and
PCBs were detected in some samples at concentrations ranging from 0.1 to 210 μg kg−1. 相似文献
15.
E. Pitarch T. Portolés J. M. Marín M. Ibáñez F. Albarrán F. Hernández 《Analytical and bioanalytical chemistry》2010,397(7):2763-2776
The presence of a wide variety of organic pollutants with different physicochemical characteristics has been investigated
in wastewater samples from a municipal solid-waste-treatment plant in Castellón, Spain. An advanced analytical strategy was
applied—combined used of two powerful and complementary techniques, GC and LC, both hyphenated with tandem mass spectrometry
with triple-quadrupole analyzers. The GC–MS–MS method was based on sample extraction using C18 SPE cartridges and enabled the determination of approximately 60 compounds from different chemical families, for example
PAHs, octyl/nonylphenols, PCBs, organochlorine compounds, insecticides, herbicides, and PBDEs. Most of the compounds selected
are included as priority contaminants in the European Union (EU) Water Directive. The UHPLC–MS–MS method, which provided high
chromatographic resolution and sensitivity and short analysis time, used sample extraction with Oasis HLB SPE cartridges and
enabled the determination of 37 (more polar) pesticides. The methodology developed was applied to the analysis of 41 water
samples (20 untreated raw leachates and 21 treated samples) collected between March 2007 and February 2009. Amounts of the
contaminants investigated rarely exceeded 0.5 μg L−1 in the treated (reverse osmosis) water samples analyzed. As expected, in untreated leachates the number of compounds detected
and the concentrations found were notably higher than in treated waters. The most commonly detected pollutants were herbicides
(simazine, terbuthylazine, terbutryn, terbumeton, terbacil, and diuron), fungicides (thiabendazole and carbendazim), and 4-t-octylphenol. The results obtained proved that use of reverse osmosis for water treatment was efficient and notably reduced
the amounts of organic contaminants found in raw leachate samples. In order to investigate the presence of other non-target
contaminants, water samples were also analyzed by using GC–TOF MS and LC–QTOF MS. Several organic pollutants that did not
form a part of the previous list of target contaminants were identified in the samples, because of the high sensitivity of
TOF MS in full-spectrum acquisition mode and the valuable accurate-mass information provided by these instruments. The insecticide
diazinon, the fungicide diphenylamide, the UV filter benzophenone, N-butylbenzenesulfonamide (N-BBSA), the insect repellent diethyltoluamide, caffeine, and the pharmaceuticals erythromycin,
benzenesulfonanilide, ibuprofen, atenolol, and paracetamol were some of the compounds identified in the water samples analyzed. 相似文献
16.
The new analytical method using Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) procedure for simultaneous determination
of diacylhydrazine insecticide residues in fruits and vegetables was developed using ultra-performance liquid chromatography
coupled with tandem mass spectrometry (UPLC-MS/MS). The four insecticides (tebufenozide, methoxfenozide, chromafenozide, and
halofenozide) were extracted from six fruit and vegetable matrices using acetonitrile and subsequently cleaned up using primary
secondary amine (PSA) or octadecylsilane (C18) as sorbent prior to UPLC-MS/MS analysis. The determination of the target compounds
was achieved in less than 3.0 min using an electrospray ionization source in positive mode (ESI+) for tebufenozide, methoxfenozide,
and halofenozide and in negative mode (ESI−) for chromafenozide. The limits of detection were below 0.6 μg kg−1, while the limit of quantification did not exceed 2 μg kg−1 in different matrices. The QuEChERS procedure by using two sorbents (PSA and C18) and the matrix-matched standards gave satisfactory
recoveries and relative standard deviation (RSD) values in different matrices at four spiked levels (0.01, 0.05, 0.1, and
1 mg kg−1). The overall average recoveries for this method in apple, grape, cucumber, tomato, cabbage, and spinach at four levels ranged
from 74.2% to 112.5% with RSDs in the range of 1.4–13.8% (n = 5) for all analytes. This study provides a theoretical basis for China to draw up maximum residue limits and analytical
method for diacylhydrazine insecticide in vegetables and fruits. 相似文献
17.
Epithermal instrumental neutron activation analysis (EINAA) technique in conjunction with anti-coincidence gamma-ray spectrometry
(AC) has been applied for the determination of ppm to ppb levels of iodine in biological materials containing high levels
of Al, Br, Cl, K, Mn, and Na. Both conventional EINAA-AC and pseudo-cyclic EINAA-AC (PC-EINAA-AC) methods using a combination
of Cd and B filters have been developed using Dalhousie University SLOWPOKE-2 reactor (DUSR) facility. The expanded uncertainties
(EU), at about 95% confidence level, for iodine in biological materials by EINAA-AC varied between 6 and 10%. The advantages
of the non-destructive PC-EINAA-AC method has been successfully demonstrated by analyzing the NIST Pine Needles (SRM 1575)
containing a low amount of iodine in presence of high quantities of Mn and other interfering elements where an iodine content
of 92.8 μg kg−1 with an EU of 6.1 μg kg−1 and a detection limit of 40 μg kg−1 has been obtained at the end of fourth cycle. 相似文献
18.
High performance liquid chromatography method for the determination of meropenem in human plasma 总被引:2,自引:0,他引:2
Summary This paper describes an HPLC method for the determination of meropenem in human plasma. The method uses solid phase extraction
(SPE) of the samples and has good sensitivity, precision and accuracy. The limit of quantification in plasma samples is 0.02
μg mL−1. Calibration curves were linear over a large dynamic range, namely within 0.02–50 μg mL−1. The method was applied to the determination of meropenem levels in patients receiving meropenem, as a single dose or at
steady state. 相似文献
19.
Tribalat L Paisse O Dessalces G Grenier-Loustalot MF 《Analytical and bioanalytical chemistry》2006,386(7-8):2161-2168
In the framework of developing analyses for exogenous contaminants in food matrices such as honey, we have compared data obtained
by high-performance liquid chromatography coupled with mass spectrometry (LC–MS) to those provided by high-performance liquid
chromatography and tandem mass spectrometry (LC–MS–MS). Initial results obtained with LC–MS showed that the technique lacked
selectivity, which is why the method was validated by LC–MS–MS. This method involves a solid-phase extraction (SPE) of nitrofuran
metabolites and nitrofuran parent drugs, a derivatization by 2-nitrobenzaldehyde for 17 h, and finally a clean-up by SPE.
The data obtained show that the limits of detection varied between 0.2 and 0.6 μg kg−1 for the metabolites and between 1 and 2 μg kg−1 for nitrofuran parent drugs. The method was applied to different flower honeys. The results showed that nitrofurans (used
as antibiotics) are consistently present in this matrix, the predominant compound being furazolidone.
Figure Working bees 相似文献
20.
Lozano A Martínez-Uroz MA Gómez-Ramos MJ Gómez-Ramos MM Mezcua M Fernández-Alba AR 《Analytical and bioanalytical chemistry》2012,402(2):935-943
Due to the basic properties of nicotine, it is not easily integrated into commonly used multiresidue methods. The present
work investigates the application of two commonly employed multiresidue methods—the QuEChERS method and the ethyl acetate
method—for determining nicotine in mushrooms. Both methods are employed in a modified form and an unmodified form: the former
to address the special properties of nicotine and the latter, combined with the use of isotopically labelled nicotine, to
compensate for poor recoveries. The QuEChERS-based methods were followed by liquid chromatography–time-of-flight mass spectrometry
and those based on ethyl acetate extraction were followed by gas chromatography–triple quadrupole-mass spectrometry. All methods
were validated according to European guidelines (document no. SANCO/10684/2009). Recovery studies performed on mushroom spiked
at 10 and 100 μg kg−1 yielded average recoveries in the range 80–110% with relative standard deviation (RSD) values below 9%. The linearity of
the response over two orders of magnitude was demonstrated (r
2 > 0.995) for all of the determination techniques employed. The limits of detection and quantification obtained were in the
0.7 and 10 μg kg−1 range, depending on the technique, and thus below the maximum residue level established for this toxic alkaloid by current
EU legislation. Good repeatability and reproducibility were obtained in terms of the RSD of the analytical methods (0.4–13.2%).
The modified QuEChERS method was tested in a proficiency test on nicotine in dried mushrooms obtaining good results. The methods
were successfully applied to 20 real samples. 相似文献