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1.
Simplified liquid-chromatographic determination of residues of tetracycline antibiotics in eggs 总被引:2,自引:0,他引:2
N. Furusawa 《Chromatographia》2001,53(1-2):47-50
Summary A high-performance liquid chromatographic (HPLC) procedure is described for the identification and quantification of residues
of tetracycline antibiotics (TCA) (oxytetracycline, tetracycline, chlortetracycline, and doxycycline), in eggs. Spiked and
blank samples were prepared by homogenization with 1∶1 (v/v) acetonitrile-mixed Mcllvaine buffer and EDTA solution (pH 4.0) then centrifugal ultrafiltration. HPLC was performed on a
reversed-phase column with acetonitrile-5% (v/v) aqueous acetic acid, 35∶65 (v/v), as mobile phase and photo-diode array detection. Average recoveries (each drug spiked at 0.1, 0.2, 0.3, 0.5 and 1.0 μg
g−1) were >-77% with standard deviations (SD) between 1.5 and 3.5%. The inter-assay variabilities and theirSD were <3.4% and <0.7%, respectively, and intra-assay variability was between 2.0 and 3.9%. The limits of quantitation (LOQ) were 0.064 0.087, 0.121, and 0.131 μg g−1 for OTC, TC, CTC, and DC, respectively. The total time required for the analysis of one sample was less than 30 min. 相似文献
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The newest results in the use of various extraction techniques and chromatographic methods such as gas-liquid and high-performance liquid chromatography used for the assessment of herbicide residues in various matrices have been compiled and critically evaluated. Practical employments in water and soil research, environmental protection, clinical and food chemistry are presented. 相似文献
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《Journal of separation science》2017,40(5):1158-1166
In this study, a new method for the determination of 12 nitroimidazoles and their hydroxymetabolites (metronidazole, hydroxymetronidazole, dimetridazole, ronidazole, hydroxydimetridazole, ipronidazole, hydroxyipronidazole, carnidazole, ornidazole, secnidazole, ternidazole, tinidazole) in beeswax has been developed and validated. The optimized sample preparation procedure included melting and dilution of beeswax in a mixture of n‐hexane and isopropanol followed by extraction with 2% acetic acid. The extracts were purified on strong cation exchange based solid‐phase extraction cartridges and evaporated in a vacuum system with vortex motion. The separation and detection of the nitroimidazoles in the beeswax extracts were achieved within 12 min by liquid chromatography tandem mass spectrometry using a pentafluorophenyl analytical column and applying a gradient elution with acetonitrile and 0.01% acetic acid as mobile phases. The method performance characteristics were evaluated at three concentration levels (1, 2, and 5 μg/kg) and the method was found to be suitable for determination of all tested nitroimidazoles. The limits of detection and quantification were 0.2–0.5 and 0.5–1 μg/kg, respectively. The recoveries varied from 71.2 to 104.9% while the relative standard deviations were less than 13.8% under the intermediate precision conditions. 相似文献
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Liquid chromatography with time-of-flight mass spectrometry (LC-TOF-MS) method has been developed for simultaneous confirmation by accurate mass measurement and quantitative determination of antibiotics (enrofloxacin, oxolinic acid, flumequine, erythromycin), fungicides (malachite green MG, leucomalachite green LMG) and parasiticide (emamectin benzoate) residues in edible portion of salmon. Confirmation of chemotherapeutant residues has been based on the system of identification points (IPs) established in the Commission Decision 2002/657/EC concerning the use of mass spectrometry (MS) techniques. A validation study on matrix is presented evaluating accuracy in terms of precision (λppm 0.83-1.15) and trueness (0.22-0.70 Da). Limits of detection (LODs) and limits of quantification (LOQs) were in ranges of 1-3 and 3-9 μg/kg, below the maximum residue limits (MRLs) established in current EU legislation (100-200 μg/kg) for these chemotherapeutants. Considering the EU guidelines, decision limits (CCα) and detection capabilities (CCβ) were determined (ranges of 103-218 and 107-234 μg/kg, respectively) for authorised substances. For no authorised compounds (MG and LMG), LODs were 2 and 1 μg/kg, respectively, but exceed the MRPL (minimum required performance limit) established in the legislation which corresponds to the sum of MG and LMG (2 μg/kg). Acceptable intra-day and inter-day variability, in terms of relative standard deviation (R.S.D.) of the analytical method, were obtained (2-15%). Linearity was demonstrated from the LOQs of the analytes to 600 μg/kg (r > 0.9991). The method has involved an extraction procedure based on solid-liquid extraction (SLE) with recoveries higher than 80% for most target chemotherapeutants, with exception of enrofloxacin (40%). 相似文献
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Simultaneous determination of herbicide residues in tobacco using ultraperformance convergence chromatography coupled with solid‐phase extraction 下载免费PDF全文
Weiyun Guo Daohong Zhang Gangling Tang Wei Liu Jianlong Wang Zhonghao Li Fei Yang 《Journal of separation science》2015,38(5):858-863
A time‐saving and organic solvent efficient method to simultaneously determine six kinds of herbicide residues in tobacco using solid‐phase extraction for sample clean‐up and preconcentration and the highly sensitive ultraperformance convergence chromatography method was developed. Parameters for ultraperformance convergence chromatography, including the choice of stationary phase and modifiers, autobackpressure regulator pressure, column temperature, and the flow rate of mobile solvents, were optimized. The herbicide residues of napropamide, alachlor, quizalofop‐ethyl, diphenamid, metolachlor, and clomazone in tobacco samples were successfully separated and detected at levels as low as 0.0043–0.0086 mg/kg within 5 min using a nonpolar high strength silica C18 selectivity for bases column and methanol as the cosolvent of the mobile phase of carbon dioxide (75–99.9%, v/v). Analysis of tobacco samples had recoveries of 69.8–95.0%, limit of quantitation of 0.0127–0.0245 mg/kg, limit of detection of 0.0043–0.0086 mg/kg, and correlation coefficient of >0.9990. Results support this method as an efficient alternative to current methodologies for the determination of herbicide residues in tobacco. 相似文献
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Summary An alternative to the traditional solvent extraction method used to extract and rapidly quantify ethyl-and vinylphenol and ethyl-and vinylgaiacol from wine is presented. The method is based on retention of volatile phenols on adsorbants. Among the tested resins, the most efficient, AG 2-X8 (anion exchange resin), worked as well with a synthetic solution as with wines. The percolation of clarified wine adjusted to pH 9 on this resin permits, in particular, the elimination of organic acids. Phenols are not eluted after rinsing the column with 1N HCl, but are eluted with methanol after this treatment. Good recovery (91 %) and good repeatability are observed. The eluate is directly analysed by HPLC on an RP18 column after two-fold dilution in water. The four volatile phenols were completely separated and detected by UV at 280 nm with high sensitivity (20–40 ppb). No interference with other compounds were noted in the different wines analysed. 相似文献
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采用乙腈提取、固相萃取(SPE)富集浓缩技术结合自行研制开发的毛细管液相色谱(CLC)仪,同时分离测定了食品和水样中1种有机磷和3种氨基甲酸酯类杀虫剂残留。对影响SPE效率和CLC分离检测的各类因素进行了优化,包括固相萃取柱种类、样品pH、洗脱剂种类和体积、上样速率、盐效应、上样体积、检测波长、流动相种类和比例等。结果表明,4种杀虫剂在6 min内达到完全分离,检出限为0.35~1.20 μg/kg,定量限为1.17~4.00 μg/kg。使用该SPE-CLC法对西红柿、黄瓜、苹果样品和自来水、湖水水样进行加标回收测定,得到食品中加标回收率为72.41%~107.15%,相对标准偏差≤8.12%;水样中加标回收率为71.45%~109.25%,相对标准偏差≤9.28%。该法能够满足农药多残留分析要求。 相似文献
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A simple, rapid, sensitive and reliable high-performance liquid chromatographic method for the simultaneous determination
of eight sulfonamides (SAs) in bovine milk was developed (sulfadiazine, sulfathiazole, sulfamethazine, sulfamethoxypyridazine,
sufamonomethoxine, sulfamethoxazole, sulfadimethoxine and sulfaquinoxaline) in bovine milk was developed. Samples were prepared
by extraction with ethyl acetate and cleaning-up with an anion solid-phase extraction (SPE) column. Analytical separation
was performed on an Inertsil ODS-3 column with photodiode-array detection at 270 nm under gradient condition. The whole procedure
was evaluated according to the European Commission Decision 2002/657/EC. Specificity, decision limit (CCα), detection capacity
(CCβ), trueness and precision were determined during the validation process. It was found that the analytes were isolated
from spiked samples with good recoveries between 70.5 and 89.0%. The used analytical conditions allow to successively separating
all the tested sulfonamides with good limit of detection between 0.8 and 1.5 μg L−1. 相似文献
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Summary The taurine content in plasma was determined by high performance liquid chromatographic analysis of its dansyl derivative
with fluorometric detection. After the reaction with dansyl chloride, the derivative was extracted from an aqueous mixture
by using tetrabutylammonium as a counter-ion. The influences of different tetrabutylammonium salts and of the eluent mixture
composition were studied. Omotaurine, added as the internal standard to the plasma samples, assured good reproducibility.
The procedure was applied to the determination of taurine in specimens from different mammalian species. 相似文献
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L. Torreti A. Simonella A. Falgiani C. Filipponi F. Gramenzi 《Journal of separation science》1987,10(9):510-515
A simple micro-method is described for determination of 15 organochlorine pesticide residues in mixed feeds. Clean-up of the petroleum ether extract is by basic alumina minicolumn chromatography and quantitative identification is by capillary gas chromatography with electron capture detection. Cyanopropyl-polysiloxane chemically bonded fused silica capillary columns have been used to perform high resolution analyses in short time as well as to overcome possible interferences by PCBs. Recovery, repeatability, and detection limits of the proposed procedure are checked and results are also reported for non random samples of 180 feeds collected in Italy. 相似文献
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Summary Selective on-line solid phase extraction (SPE) and liquid chromatography determination (HPLC) of diquat, paraquat and difenzoquat
from environmental water samples has been accomplished with Graphitized Carbon Black (GCB) as both extraction and analytical
columns. The method involved passing of 50 mL of water through a cartridge filled with Carbograph. In the elution step, the
herbicides were transferred from the cartridge to the analytical column (Hypercarb) by mean of a gradient of pH 3 aqueous
solution of tetramethylammonium hydroxide (TMAOH) and ammonium sulphate and methanol. Hypercarb columns were found to give
a low probability of false positives for bypiridylium herbicides and are very selective for polar compounds. Recovery was
better than 80 %. The breakthrough volume was studied with distilled water spiked with the herbicides at various concentration
levels (from 0.1 to 20 μg L−1). The limits of quantification of the method were lower than 0.1 μg L−1. The total analytical method was applied to surface waters from Torreblanca Nature Park (Castelló, Spain).
Presented at the 21st ISC held in Stuttgart, Germany, 15th–20th September, 1996. 相似文献
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Summary In this study a high-performance liquid chromatography method was developed for the determination of procyanidin dimers B1,
B2, B3, B4 and procyanidin trimers C1 and T2 in white wine using fluorescence detection. This method allowed analysis of white
wine with no prior treatment. Limits of quantification were form 12 μg.L−1 to 16 μg.L−1. Reproductibility data for replicate analysis was measured and the CV was less than 4.5%. This method was used for the determination
of these compounds in six French white wines. 相似文献
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Summary Lansoprazole is a new inhibitor of gastric proton secretion. An HPLC method for the quantitative determination of lansoprazole
in serum is described. The method consists of liquid-liquid extraction and enrichment of the analyte and subsequent reverse-phase
liquid chromatography with UV detection. The method is specific, sensitive and practical. It has been applied to serum from
healthy volunteers.
Presented at the 21st ISC held in Stuttgart, Germany, 15th–20th September, 1996 相似文献
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Simultaneous determination of ten organophosphate pesticide residues in fruits by gas chromatography coupled with magnetic separation 下载免费PDF全文
In this study, γ‐Fe2O3/chitosan magnetic microspheres were synthesized and evaluated by X‐ray diffraction, SEM, thermogravimetric analysis, and static and kinetic adsorption experiments. Results showed that the magnetic microspheres exhibited good adsorption ability, and offered fast kinetics for the adsorption of trichlorfon, methamidophos, malathion, methyl parathion, dimethoate, omethoate, phosphamidon, phorate, isocarbophos, and chlorpyrifos. Based on magnetic separation, a simple method of magnetic SPE coupled to GC for the simultaneous determination of ten trace organophosphate pesticide residues was developed. Under the optimal conditions, the enrichment factor for ten organophosphorus pesticides was 10.1–364.7 and linear range was 0.001–10.0 mg/L. The LOD (S/N = 3) of the method for the ten pesticides was 0.31–3.59 μg/kg. The RSD for three replicate extractions of spiked samples was between 2.5 and 6.3%. The pear and apple samples spiked with ten organophosphate pesticides at 20 and 200 μg/kg levels were extracted and determined by this method with good recoveries ranging from 79.9 to 98.7%. Moreover, the method has been successfully applied for the determination of the ten organophosphate pesticide residues in peach samples. 相似文献
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Xiangji Zeng 《Chromatographia》1998,48(7-8):589-590
Summary Berberine absorption by patients with ischemic heart failure (IHF) after oral administration and the relationship between
clinical effect and plasma berberine concentration are studied. Plasma samples were pretreated by chloroform extraction. Berberine
was determined on a μBondapak column with acetonitrile-phosphoric acid mobile phase and UV detection. The limit for berberine
in plasma was 8 ng mL−1 for an injection volume of 50 μL. Average berberine recovery was 96.5%. Results showed that improvements in symptoms were
more significant for patients with plasma berberine concentration>0.1 mg L−1 than for those with<0.1 mg L−1. Plasma berberine monitoring may be helpful in the treatment of patients with IHF. 相似文献