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1.
Qian M Wu L Zhang H Xu M Li R Wang X Sun C 《Analytical and bioanalytical chemistry》2012,402(7):2451-2462
A new sensitive multiresidue liquid chromatography–tandem mass spectrometry (LC-MS/MS) analytical method for the determination
of 16 insect growth regulator (IGR) residues—RH-5849 (1,2-dibenzoyl-1-tert-butylhydrazine), halofenozide, methoxyfenozide, chromafenozide, fufenozide, tebufenozide, diflubenzuron, chlorbenzuron, triflumuron,
hexaflumuron, novaluron, lufenuron, teflubenzuron, flucycloxuron, flufenoxuron, and chlorfluazuron—in herbs (Perilla frutescens, flos chrysanthemi, lily bulbs, and ginger) has been developed. After the herbs had been extracted with acetonitrile, a combined
graphitized nonporous carbon/aminopropyl (ENVI-Carb/LC-NH2) cartridge and a Florisil cartridge were used to clean up the extracts. LC-MS/MS was performed in multiple reaction monitoring
mode with two specific precursor ion–product ion transitions per IGR to confirm and quantitate the residues in herbs. Quantitation
was performed on the basis of matrix-matched calibrations. The method showed excellent linearity (r
2 > 0.99) and precision (relative standard deviations of 13.6 or lower) for all the target insecticides. The limits of quantitation
were 0.6-10 μg kg-1 for the 16 insecticides in the four herbs. The average recoveries, measured at three concentrations (0.01, 0.1, 1 mg kg-1), were in the range 74.8-105.3%. The method was satisfactorily applied for the analysis of 60 herb samples (Perilla frutescens, flos chrysanthemi, lily bulbs, and ginger). Hexaflumuron was detected at concentrations of 0.029 and 0.051 mg kg-1 in Perilla frutescens. 相似文献
2.
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
3.
Aguilera-Luiz MM Plaza-Bolaños P Romero-González R Vidal JL Frenich AG 《Analytical and bioanalytical chemistry》2011,399(8):2863-2875
A rapid multi-analyte method has been developed for the simultaneous determination of pesticides and mycotoxins in milk by
ultra high-performance liquid chromatography coupled to triple quadrupole mass spectrometry (UHPLC–QqQ–MS/MS). A variety of
methodologies has been evaluated, including solid-phase extraction (SPE), “dilute-and-shoot” (liquid–liquid extraction-based
procedures), and QuEChERS (quick, easy, cheap, effective, rugged, and safe)-based methods. The optimization and development
process was carried out considering that the maximum residue level for aflatoxin M1 (AFM1) in milk in the European Union (EU)
is set at 0.05 μg kg−1, which is the lowest tolerance in the target compounds. The selected method consisted of an extraction by SPE using C18 as
sorbent and methanol as elution solvent. The final determination was performed by UHPLC–QqQ–MS/MS. Matrix-matched standard
calibration was used for quantification, obtaining recoveries in the range 60–120% with relative standard deviations <25%,
at three spiking levels: 0.5, 10, and 50 μg kg−1 (ten times lower for AFM1). Limits of quantification ranged from 0.20 to 0.67 μg kg−1, which were always below or equal to the established tolerance levels by the EU. Finally, the selected method was applied
to different types of milk. 相似文献
4.
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
5.
Arroyo-Manzanares N García-Campaña AM Gámiz-Gracia L 《Analytical and bioanalytical chemistry》2011,401(9):2987-2994
Ochratoxin A (OTA) is a mycotoxin naturally found in various foods, including wine. As OTA is considered as a possible human
carcinogen, the maximum concentration for this compound has been established at 2 μg kg−1 in wine by the EU (Directive (CE) No 1881/2006). Typically, immunoaffinity columns have been used for its extraction. However,
simpler, more efficient and less contaminant extraction systems are demanding. In this work, dispersive liquid–liquid microextraction
using ionic liquid as extractant solvent (IL-DLLME) and the QuEChERS procedure, have been evaluated and compared for extraction
of OTA in wine samples. Laser-induced fluorescence (LIF, He–Cd Laser excitation at 325 nm) coupled with capillary HPLC has
been used for the determination of OTA, using a sodium dodecyl sulfate micellar solution in the mobile phase to increase the
fluorescence intensity. Matrix-matched calibration curves were established for both methods, obtaining LODs (3× S/N) of 5.2 ng·L−1 and 85.7 ng·L−1 for IL-DLLME and QuEChERS, respectively. Clean extracts were obtained for white, rose and red wines with both methods, with
recoveries between 88.7–94.2% for IL-DLLME and between 82.6–86.2% for QuEChERS. The precision was evaluated in terms of repeatability
(n = 9) and intermediate precision (n = 15), being ≤ 8.5% for IL-DLLME and ≤ 5.4% for QuEChERS. 相似文献
6.
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
7.
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
8.
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
9.
A new method for the analysis of three ecological insecticides, namely azadyrachtin, spinosad (sum of spinosyn A and spinosyn
D) and rotenone, in produce and soil samples is presented. Investigated compounds are one of the most significant insecticides
authorized for organic farming crop protection in many countries. Extraction of the pesticides from plant and soil matrices
was performed by using a modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) method. The method entailed a
single extraction of the investigated compounds with acidified acetonitrile followed by a dispersive solid-phase extraction
cleanup step prior to the final determination by reverse-phase ultra-performance liquid chromatography/tandem quadrupole mass
spectrometry (UPLC-MS/MS). Validation studies were carried out on cabbage, tomato and soil samples. Recoveries of the spiked
samples were in the range between 67% and 108%, depending on the matrix and the spiking level. Relative standard deviations
for all matrix–compound combinations did not exceed 12%. The limits of quantification were ≤0.01 mg kg−1 in all cases, except for azadirachtin. The developed method was applied to the analysis of real samples originating from
organic farming production. 相似文献
10.
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
11.
Larivière D Tremblay M Durand-Jézéquel M Tolmachev S 《Analytical and bioanalytical chemistry》2012,403(2):409-418
This article describes a robust methodology using the combination of instrumental design (high matrix interface—HMI), sample
dilution and internal standardization for the quantification of beryllium (Be) in various digested autopsy tissues using inductively
coupled plasma mass spectrometry. The applicability of rhodium as a proper internal standard for Be was demonstrated in three
types of biological matrices (i.e., femur, hair, lung tissues). Using HMI, it was possible to achieve instrumental detection
limits and sensitivity of 0.6 ng L−1 and 157 cps L ng−1, respectively. Resilience to high salt matrices of the HMI setup was also highlighted using bone mimicking solution ([Ca2+] = 26 to 1,400 mg L−1), providing a 14-fold increase in tolerance and a 2.7-fold decrease in method detection limit compared to optimized experimental
conditions obtained without the HMI configuration. Precision of the methodology to detect low levels of Be in autopsy samples
was demonstrated using hair and blood certified reference materials. Be concentration ranging from 0.015 to 255 μg kg−1 in autopsy samples obtained from the U.S. Transuranium and Uranium Registries were measured using the methodology presented. 相似文献
12.
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
13.
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
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.
《Analytical letters》2012,45(15):2340-2348
A simple and rapid micellar electrokinetic capillary chromatography method of trifloxystrobin, tebufenozide, and halofenozide has been developed. The separation was performed in a 10 mM borate-18 mM SDS buffer solution (pH = 9.0), containing 22.5% v/v of acetonitrile, 25 kV and detection at 202 nm. The linear concentration range of application was 0.5–10.0 mg L?1, with a detection limit of 0.094 mg kg?1 for trifloxystrobin and 0.088 mg kg?1 for tebufenozide and halofenozide. Analysis yielded good reproducibility (RSD between 1.7–8.7%). The applicability of the method was tested by analyzing several fortified samples of tomato, celery, and apple juices. Recovery levels were between 70.0 and 110.8%. 相似文献
16.
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
17.
Hyoe Takata Tatsuo Aono Keiko Tagami Shigeo Uchida 《Journal of Radioanalytical and Nuclear Chemistry》2011,287(3):795-799
For safety assessments of geological repositories of nuclear waste, understanding of uranium (U) fate in estuarine areas is
important because U chemical behavior in the areas is expected to be complex. Environmental transfer parameters such as sediment–water
distribution coefficients (K
d) and concentration ratios (CRs) for marine organisms are useful in mathematical models for the assessment. However, due to
its low concentration in estuarine water, K
d and CF data for U are scarce. Thus we studied a rapid method for separation and concentration of U from estuarine water samples
using NOBIAS-CHELATE PA1 resin columns followed by inductively coupled plasma mass spectrometry (ICP-MS) for U measurement.
Chemical recovery was about 100% at pH of 5.7 ± 0.1 from the water samples and alkali and alkaline earth metals were removed.
The method was used to measure U concentrations in estuarine water samples collected at eight Japanese estuarine areas; they
ranged from 0.1 to 3.8 μg L−1. We also measured U concentrations in sediment and marine organism samples by ICP-MS after acid digestion. Using these values,
we observed K
d (range: 39–284 L kg−1) and CRs (0.86–52 L kg−1 for macroalgae, 0.087–15 L kg−1 for crustaceans, and 0.52–93 L kg−1 for molluscs). 相似文献
18.
López-Darias J Pino V Ayala JH González V Afonso AM 《Analytical and bioanalytical chemistry》2008,391(3):735-744
An environmentally friendly method to extract endocrine-disrupting phenols (EDPs) from seawaters was realized using nonionic
surfactant mixtures and micelle-mediated extractions. The preconcentration step was achieved directly in the seawater matrix,
and was followed by high-performance liquid chromatography (HPLC) with ultraviolet (UV) detection without any clean-up steps
to remove the surfactant mixture prior to injection. Various nonionic surfactant mixtures were used, and polyoxyethylene-10-laurylether
(POLE) with polyoxyethylene-4-laurylether (Brij 30) was found to be the best to work with. Method optimization involved maximizing
the preconcentration factor using the studied mixtures. The proposed method gave extraction recoveries ranging from 83.3 to
114.4% for an EDP spiking level of 46.7 μg L−1, and from 63.4 to 112.4% for a spiking level of 4.7 μg L−1 for EDPs studied in real seawater matrices, with relative standard deviations of <12.1%. The detection limits of the method
varied from 0.18 μg L−1 for bisphenol A (BPA) to 1.17 μg L−1 for 4-cumylphenol (4-CP). The method was applied to seawaters from the Canary Islands with successful results.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
19.
《Arabian Journal of Chemistry》2020,13(3):4681-4690
A modified QuEChERS method (Quick, Easy, Cheap, Effective, Rugged, and Safe) for the determination of fifteen phenolic compounds in mustard greens (Brassica juncea) using ultra-high-performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS) analysis was developed. The QuEChERS partitioning step and dispersive solid phase extraction (d-SPE) clean-up sorbents were investigated, aimed at phenolic compound extraction and pigment removal, respectively. QuEChERS acetate version combined with 25 mg of diatomaceous earth (DE) and 5.0 mg of graphitized carbon black (GCB) provided the best conditions for sample preparation of the target compounds. Under the optimized conditions, all phenolic compounds showed good linearity (r ≥ 0.99) over the concentration range of 0.1 to 8000 μg kg−1, and the quantification limits were in the range of 0.06–230 μg kg−1. The spectrophotometric analysis showed that the clean-up step promoted a significant removal of chlorophyll, which is the major pigment present in the sample. Furthermore, antioxidant activity analysis was also carried out after the clean-up step and, together with chromatographic data, showed that no significant retention of the phenolic compounds occurs in the clean-up step. Two mustard greens varieties – Southern Giant Curled (SGC) and Florida Broadleaf (FB) - were analyzed with the proposed method. Seven phenolic compounds (4-hydroxybenzoic, p-coumaric, ferulic and sinapic acids, naringenin, apigenin and kaempferol) were found in both varieties, the greatest abundance being for sinapic acid (1261.5 ± 23 μg kg−1 in SGC and 1235.5 ± 26 μg kg−1 in FB) and ferulic acid (2861 ± 24 μg kg−1 in SGC and 3204.5 ± 45 μg kg−1 in FB). 相似文献
20.
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