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1.
Li X Wang G Xie H Wang R Xu M Wang W Tao J Sun J 《Analytical and bioanalytical chemistry》2006,384(4):958-963
A rapid, reproducible high-performance liquid chromatographic (HPLC) method with fluorescence detection for the simultaneous
determination of 3(or 8)-(1-methoxyethyl)-8(or 3)-(1-hydroxyethyl)-deuteroporphyrin IX (MHD) and 3,8-di-(1-methoxyethyl)-deuteroporphyrin
IX (DMD) in dog plasma was described. Fluorescein was used as an internal standard. A simple extraction step with ethyl acetate
was performed before chromatography on a Diamonsil C18 column (5 μm, 4.6 mm×150 mm). The chromatography used 0.02 mol L−1 sodium acetate/tetrahydrofuran (66:34 v/v). The analytical curve was linear over the concentration range 0.025– 2.5 μg mL−1. For a 100 μL dog plasma sample, the limit of determination for both MHD and DMD was 0.025 μg mL−1. The recoveries of MHD and DMD were more than 76% and 89%, respectively. The intra-assay (within-run) and interassay (between-run)
coefficients of variation (precisions) for MHD and DMD were less than 15%. This method was found to be suitable for the analysis
of biosamples and was successfully applied to pharmacokinetic studies of Deuxemether in dogs. 相似文献
2.
Cantú MD Toso DR Lacerda CA Lanças FM Carrilho E Queiroz ME 《Analytical and bioanalytical chemistry》2006,386(2):256-263
Simple, sensitive, and reproducible off-line solid-phase microextraction and liquid chromatography (SPME/LC) methods are described
for the determination of seven anticonvulsants and tricyclic antidepressants in human plasma. Factorial design and simplex
methodology were applied in the optimization of the SPME procedure for tricyclic antidepressants analyses. Important factors
in the SPME efficiency are discussed, such as the fiber coatings (both lab-made and commercial), extraction time, pH, ionic
strength, influence of plasma proteins, and desorption conditions. The development of the lab-made fiber coatings, namely,
octadecylsilane, aminosilane, and polyurethane, are further described and applied to anticonvulsants analyses. The investigated
plasmatic range for the evaluated anticonvulsants, using CW-TPR fiber, were the following: phenylethylmalonamide (3.00–40.0 μg
mL−1), phenobarbital (5.00–40.0 μg mL−1), primidone (3.00–40.0 μg mL−1), carbamazepine and carbamazepine-epoxide (2.00–24.0 μg mL−1), phenytoin (2.00–40.0 μg mL−1), and lamotrigine (0.50–12.0 μg mL−1). The antidepressants’ linear plasmatic concentration ranged from 75.0 to 500 ng mL−1 for imipramine, amitriptyline, and desipramine, and from 50.0 to 500 ng mL−1 for nortriptyline, being in all cases, the limit of quantification represented by the lowest value. The precision (interassays)
for all investigated drugs in plasma sample spiked with different concentrations of each analyte and submitted to the described
procedures were lower than 15%. The off-line SPME/LC methodologies developed allow anticonvulsants and antidepressants analyses
from therapeutic to toxic levels for therapeutic drug monitoring. 相似文献
3.
Lei Zhang Liang Xu Xiao-Jie Tan Qiong-Feng Liao Wei Guo Xiao-Hui Chen Kai-Shun Bi 《Chromatographia》2007,66(1-2):115-120
A sensitive and reliable ion-paired high-performance liquid chromatographic method has been established for the simultaneous
quantification of six major active ingredients, namely baicalin, baicalein, wogonin, oxysophocarpine, oxymatrine and matrine
in the Chinese herbal preparation, Sanwu-Huangqin-Tang. HPLC analyses were performed on a Phenomenex luna C18 column with mobile phase of methanol–acetonitrile–aqueous phosphoric acid at a flow rate of 0.9 mL min−1. The complete separation was achieved within 35 min for the six target constituents. A good linear regression relationship
between peak-areas and concentrations was obtained over the range of 12.10–242.0 μg*mL−1 for baicalin, 5.05–101.0 μg*mL−1 for baicalein, 0.95–19.0 μg*mL−1 for wogonin, 2.75–55.0 μg*mL−1 for oxysophocarpin, 2.75–55.0 μg*mL−1 for oxymatrine and 4.90–98.0 μg*mL−1 for matrine, respectively. The repeatability was evaluated by intra- and inter-day assays with relative standard deviation
(RSD) being less than 5.1%. The recoveries, measured at three concentration levels, varied from 93.8 to 102.1%. The assay
was successfully applied for determination of six bioactive compounds in Sanwu-Huangqin-Tang. The interaction of chemical
constituents was observed when the herbs were used in compatibility. The results indicated that the developed assay method
was rapid, accurate and could be readily utilized as a quality control method for Sanwu-Huangqin-Tang. 相似文献
4.
M. A. Campanero A. M. Zamarreño M. Simón M. C. Dios J. R. Azanza 《Chromatographia》1997,46(7-8):374-380
Summary A simple and rapid liquid chromatographic method has been developed for the determination of therapeutic levels of piperacillin
(I) and ceftazidime (II) in human plasma. Plasma and p-propionamidophenol (internal standard) were precipitated with methanol
(I) or 20% trichloroacetic acid (II). The supernatant was analysed on a 5 μm Spherisorb ODS C18 column with acetonitrile-0.05 M phosphate buffer pH 3.8 as mobile phase and ultraviolet detection at 254 nm. The calibration
graph was linear from 10 to 250 μg mL−1, for (I), and from 5 to 200 μg mL−1 for (II). Intra and inter-day CV did no exceed 2.29% for (I), and were 10.76–11.13%–2.00–5.62 for (II) at concentrations
of 10 μg mL−1 and 250 μg mL−1. 相似文献
5.
A new method was developed for the simultaneous determination of lidocaine, proline and lomefloxacin in human urine by capillary
electrophoresis-electrochemiluminescence detection with Ru(bpy)3
2+. Conditions of the separation and detection were investigated and optimized. It was proved that 20 mM phosphate buffer at
pH 6.7 could achieve the most favorable resolution, and the high sensitivity of detection was obtained by using the detection
potential at 1.15 V and 5 mM Ru(bpy)3
2+–60 mM phosphate buffer at pH 7.6 in the detection reservoir. The detection limits were 0.02 μg mL−1 for lidocaine, 0.03 μg mL−1 for proline and 0.06 μg mL−1 for lomefloxacin. Relative standard deviations of the ECL intensity and the migration time were 3.5 and 1.1% for 6 μg mL−1 lidocaine, 3.2 and 1.0% for 6 μg mL−1 proline and 3.7 and 1.2% for 6 μg mL−1 lomefloxacin, respectively. A baseline separation for lidocaine, proline and lomefloxacin was achieved within 360 s. The
developed method was successfully applied to determine the amounts of lidocaine, proline and lomefloxacin in human urine.
The recovery and RSD were in the range of 93.3–97.2 and 3.8–4.9%, respectively. 相似文献
6.
Tetracycline antibiotics (TCs) such as doxycycline (DOTC), chlortetracycline (CTC), oxytetracycline (OTC), and tetracycline
(TC) react with Cu(II) in pH 3.5 BR buffer medium to form 1:1 cationic chelates, which further react with titan yellow to
form 2:1 ion association complexes. These result in great enhancement of resonance Rayleigh scattering (RRS) and the appearance
of new RRS spectra. The ion association complexes of DOTC, CTC, OTC, and TC have similar spectral characteristics and their
maximum RRS wavelengths are all located at 464 nm. The quantitative determination ranges and the detection limits (3σ) of the four TCs are 0.037–4.8 μg mL−1 and 11.2 ng mL−1 for DOTC, 0.041–5.2 μg mL−1 and 12.4 ng mL−1 for CTC, 0.050–4.8 μg mL−1 and 15.1 ng mL−1 for TC, and 0.088–5.0 μg mL−1 and 26.3 ng mL−1 for OTC, respectively. The optimum reaction conditions, the effects of foreign substances, the structure of ternary complexes,
and the reaction mechanism are discussed. A sensitive, rapid, and simple RRS method for the determination of DOTC has been
developed. 相似文献
7.
Protein can greatly enhance the fluorescence of curcumin (CU) in the presence of sodium dodecyl benzene sulfonate (SDBS).
Experiments indicate that under the optimum conditions, the enhanced intensity of fluorescence is proportional to the concentration
of proteins in the range of 0.0050–20.0 μg mL−1 for bovine serum albumin (BSA), 0.080–20.0 μg mL−1 for human serum albumin (HSA), and 0.040–28.0 μg mL−1 for egg albumin (EA). Their detection limits (S/N=3) are 1.4 ng mL−1, 20 ng mL−1, and 16 ng mL−1, respectively. The method has been satisfactorily used for the determination of proteins in actual samples. In comparison
with most of fluorimetric methods, this method is quick and simple, has high sensitivity and good stability. The interaction
mechanism is also studied. 相似文献
8.
Summary Direct chiral-phase HPLC methods have been developed for the determination of flurbiprofen and its major metabolites, namely
4′-hydroxyflurbiprofen and 3′-hydroxy-4′-methoxyflurbiprofen, in biological fluids using a derivatized amylose chiral stationary
phase (CSP; Chiral-pak AD). Quantification of all three analytes, both free and conjugated, in urine was carried out following
liquid-liquid extraction using tandem ultraviolet (UV) and fluorescence detection. Determination of flurbiprofen and the 4′-hydroxy-metabolite
in plasma utilized the same CSP but required modification in the mobile phase composition and sole use of fluorescence detection.
The urine assay was linear (r>0.998) between 0.05–10 μg mL−1, 0.1–20 μg mL−1 and 0.01–2 μg mL−1 for the enantiomers of flurbiprofen, 4′-hydroxyflurbiprofen and 3′-hydroxy-4′-methoxyflurbiprofen respectively. The plasma
assay was linear (r>0.997) between 0.1–6 μg mL−1 and 0.01–0.6 μg mL−1 for the enantiomers of flurbiprofen and 4′-hydroxyflurbiprofen respectively. Both assays, typically yielded within- and between-day
imprecision and accuracy values less than 10% for the enantiomers of the different analytes. Initial volunteer studies suggest
that the disposition of flurbiprofen displays modest enantioselectivity in humans. 相似文献
9.
Graziele P. Ramos Paula M. B. Dias Cláudia B. Morais Pedro E. Fröehlich Miguel Dall’Agnol José A. S. Zuanazzi 《Chromatographia》2008,67(1-2):125-129
Red clover (Trifolium pratense L.) is an important forage plant that contains the isoflavones daidzein, genistein, formononetin, and biochanin A. These
compounds have been studied lately due to their human health benefits. The aim of this study was to develop and validate an
HPLC method with simplified sample preparation to quantify daidzein, genistein, formononetin and biochanin A simultaneously
in red clover leaves. The validation showed that the method is specific, accurate, precise and robust, not to mention that
the sample preparation is easier and faster than those described earlier. The response was linear over a range of 0.01–0.2 μg mL−1 for daidzein, 0.05–0.5 μg mL−1 for genistein, 4–40 μg mL−1 for formononetin and 2–20 μg mL−1 for biochanin A. The range of recoveries was 85.6–101.0%. The RSD for intra- and inter-day precision were <2.54 and <7.22%,
respectively. Five populations of red clover, from the National Plant Germplasm System-USDA were analyzed and the content
of daidzein, genistein, formononetin and biochanin A ranged from 7.87–91.31, 51.60–131.30, 6568.33–23461.82, to 2499.55–10337.33 μg g−1 of dried material, respectively. 相似文献
10.
Summary A reversed-phase ion-pair chromatographic (RPIPC) method withN,N,N′, N′-ethylenediaminetetrakis(methylenephosphonic acid) (EDTMP) as coordinating agent has been developed for simultaneous separation
and detection of Cu(II), Fe(III), and Pb(II) ions. Response is linearly dependent on amount of sample over the range 9.52–50.8
μg mL−1 for Cu(II), 8.31–41.8 μg mL−1 for Fe(III), and 37.3–51.8 μg mL−1 for Pb(II). The method has been applied successfully to an artificial mixed-ore sample. 相似文献
11.
A simple, rapid, and precise reversed-phase high-performance liquid chromatographic method has been developed for simultaneous determination of losartan potassium, ramipril, and hydrochlorothiazide. The three drugs were separated on a 150 mm × 4.6 mm i.d., 5 μm particle, Cosmosil C18 column. The mobile phase was 0.025 m sodium perchlorate–acetonitrile, 62:38 (v/v), containing 0.1% heptanesulphonic acid, pH adjusted to 2.85 with orthophosphoric acid, at a flow rate of 1.0 mL min−1. UV detection was performed at 215 nm. The method was validated for linearity, accuracy, precision, and limit of quantitation. Linearity, accuracy, and precision were acceptable in the ranges 35–65 μg mL−1 for losartan, 1.75–3.25 μg mL−1 for ramipril, and 8.75–16.25 μg mL−1 for hydrochlorothiazide. 相似文献
12.
A high-performance liquid chromatography–UV method for determining DCJW concentration in rat plasma was developed. The method
described was applied to a pharmacokinetics study of intramuscular injection in rats. The plasma samples were deproteinized
with acetonitrile in a one-step extraction. The HPLC assay was carried out using a VP-ODS column and the mobile phase consisting
of acetonitrile–water (80:20, v/v) was used at a flow rate of 1.0 mL min−1 for the effective eluting DCJW. The detection of the analyte peak area was achieved by setting a UV detector at 314 nm with
no interfering plasma peak. The method was fully validated with the following validation parameters: linearity range 0.06–10 μg mL−1 (r > 0.999); absolute recoveries of DCJW were 97.44–103.46% from rat plasma; limit of quantification, 0.06 μg mL−1 and limit of detection, 0.02 μg mL−1. The method was further used to determine the concentration–time profiles of DCJW in the rat plasma following intramuscular
injection of DCJW solution at a dose of 1.2 mg kg−1. Maximum plasma concentration (C
max) and area under the plasma concentration–time curve (AUC) for DCJW were 140.20 ng mL−1 and 2405.28 ng h mL−1. 相似文献
13.
Capitán-Vallvey LF Valencia MC Arana Nicolás E García-Jiménez JF 《Analytical and bioanalytical chemistry》2006,385(2):385-391
An integrated solid-phase spectrophotometry–FIA method is proposed for simultaneous determination of the mixture of saccharin
(1,2-benzisothiazol-3(2H)-one-1,1-dioxide; E-954) (SA) and aspartame (N-l-α-aspartyl-l-phenylalanine-1-methyl ester; E-951) (AS). The procedure is based on on-line preconcentration of AS on a C18 silica gel minicolumn and separation from SA, followed by measurement, at λ=210 nm, of the absorbance of SA which is transiently retained on the adsorbent Sephadex G-25 placed in the flow-through cell
of a monochannel FIA setup using pH 3.0 orthophosphoric acid–dihydrogen phosphate buffer, 3.75×10–3 mol L−1, as carrier. Subsequent desorption of AS with methanol enables its determination at λ=205 nm. With a sampling frequency of 10 h−1, the applicable concentration range, the detection limit, and the relative standard deviation were from 1.0 to 200.0 μg mL−1, 0.30 μg mL−1, and 1.0% (80 μg mL−1, n=10), respectively, for SA and from 10.0 to 200.0 μg mL−1, 1.4 μg mL−1, and 1.6% (100 μg mL−1, n=10) for AS. The method was used to determine the amounts of aspartame and saccharin in sweets and drinks. Recovery was always
between 99 and 101%. The method enabled satisfactory determination of blends of SA and AS in low-calorie and dietary products
and the results were compared with those from an HPLC reference method. 相似文献
14.
Summary A method was developed for the separation and quantification of the warfare nerve agent sarin (O-isopropylmethylphosphonoflouridate), its metabolite methylphosphonic acid, the anti nerve agent drug pyridostigmine bromide
(PB;3-dimethylaminocarbonyloxy-N-methyl pyridinium bromide) and its metaboliteN-methyl-3-hydroxypyridinium bromide in rat plasma and urine. The method involved using solid phase extraction and high performance
liquid chromatography (HPLC) with reversed phase C18 column, and UV detection at 280 nm. The compounds were separated using gradient of 1% to 55% acetonitrile in 0.1% triflouroacetic
acid water solution (pH 3.20) at flow rate of 0.9 ml/min in a period of 15 min. The retention times ranged from 4.4–12.1 min.
The limits of detection were 50 ng mL−1 for PB andN-methyl-3-hydroxypyridinium bromide, and 10 μg mL−1 for sarin and methylphosphonic acid, while limits of quantitation were between 100 ng mL−1–12 μg mL−1. Average percentage recovery of five spiked samples from plasma were 84.6±8.4, 86.5±9.0, 76.4±8.5, 81.3±8.2, and from urine
78.5±7.9, 76.4±7.8, 74.4±8.4, 80.6±6.8 for sarin, methylphosphonic acid, pyridostigmine bromide andN-methyl-3-hydroxypyridinium bromide, respectively. This method was applied to analyze the above chemicals and metabolites
following combined administration in rats. 相似文献
15.
Determination of phenazopyridine in human plasma by high performance liquid chromatography 总被引:1,自引:0,他引:1
Summary A simple, low-cost, sensitive and selective HPLC method was developed for the determination of phenazopyridine in human plasma.
The method employs UV detection of phenazopyridine and of the internal Standard at 2 different wavelengths. Calibration curves
were linear over a large dynamic range, i.e., within 0.05–10.0 μg mL−1 with limit of quantification of 0.05 μg mL−1, and a limit of detection of 0.01 μg mL−1. 相似文献
16.
Rodrigo S. Muceneeki Clarissa M. Amorim Talita G. Cesca Maique W. Biavatti Tania M. B. Bresolin 《Chromatographia》2009,69(Z2):219-223
The Mikania genus is widely known as guaco and is used to treat fever, rheumatism, influenza and respiratory diseases. This article deals
with the simultaneous quantification of three commercially available phenolic markers (o-coumaric acid, coumarin and syringaldehyde) in M. laevigata extracts, through LC-PDA. The validation data show that the method is specific, accurate, precise and robust, and also indicative
of the stability of guaco extract. The method was linear, over a range of 1.25–20.0 μg mL−1 for o-coumaric acid, 2.5–40.0 μg mL−1 for coumarin, and 0.25–4.0 μg mL−1 for syringaldehyde. The range of recovery was 94.3–96.4% for all the components, at a level of 100%. 相似文献
17.
A simple, reproducible, and efficient liquid chromatographic method was developed with UV detection. Water (0.05% TFA):acetonitrile
(0.05% TFA) was used as the mobile phase in a gradient system for the determination of procyanidin B2 (PB2) and epicatechin
(EC) in the bark of Guazuma ulmifolia Lam. The analysis was performed using a Phenomenex Gemini RP C18 column (5 μm) as stationary phase, at 30 °C, with a flow rate of 0.8 mL min−1, at a wavelength of 210 nm for detection and determination. The main validation parameters of the method were also determined.
Calibration curves were found to be linear, with ranges of 20.00–150.00 (PB2) and 10.00–110.00 μg mL−1 (EC). The correlation coefficients of linear regression analysis were between 0.9981 and 0.9988, and the detection limits
were between 2.89 and 2.54 μg mL−1. The contents of PB2 and EC were successfully determined, with satisfactory reproducibility and recovery. Recoveries of the
PB2 and EC were 103.00 and 104.01%, respectively. The method was successfully applied to the determination of procyanidins
in the bark of G. ulmifolia. 相似文献
18.
A novel kinetic spectrofluorimetric method for the determination of uric acid based on the activation effect of uric acid
on the Cu(II) ion catalyzed oxidation of pyronine Y by hydrogen peroxide was developed. The influence of different buffer
solutions was tested and the Britton-Robinson buffer solution with pH 2.2 was found to be the optimum. The detection limit
and the linear range for uric acid are 0.09 μg mL−1 and 0.3–3.0 μg mL−1, respectively. The RSD for eleven determinations of 1.6 μg mL−1 uric acid was 1.6 %. Satisfactory results were obtained when using this method of uric acid determination in human urine. 相似文献
19.
Differentiation of certified brands of origins of Spanish white wines by HS-SPME-GC and chemometrics 总被引:1,自引:0,他引:1
Jurado JM Ballesteros O Alcázar A Pablos F Martín MJ Vilchez JL Navalón A 《Analytical and bioanalytical chemistry》2008,390(3):961-970
A headspace solid-phase microextraction gas-chromatographic (HS-SPME-GC) procedure was used to determine the composition of
the volatile fraction of white wine samples from several Spanish certified brands of origin (CBO). The compounds present were
previously identified by gas chromatography−mass spectrometry (GC−MS) and quantitative determinations were carried out by
GC-FID. Four CBO, Rueda, Ribeiro, Penedés, and Condado de Huelva, were studied. Rueda wines present the highest concentrations
of ethyl acetate (55.86−125.27 μg mL−1), isoamyl acetate (0.91−6.72 μg mL−1), hexyl acetate (0.09−0.81 μg g mL−1), and 2-phenethyl acetate (0.14−0.66 μg mL−1). Compounds such as ethyl hexanoate (0.88−2.15 μg mL−1) and ethyl decanoate (0.29−0.96 μg mL−1) appeared in higher concentration in Ribeiro, Rueda, and Penedés samples. According to the results obtained and by applying
pattern-recognition procedures differentiation of the considered CBO was attained. Principal-component analysis (PCA), linear
discriminant analysis (LDA), and multilayer perceptrons neural networks (MLP-NN) were used as chemometric tools for pattern-recognition
studies.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
20.
B. Venkateswara Reddy K. V. N. Suresh Reddy J. Sreeramulu G. V. Kanumula 《Chromatographia》2007,66(1-2):111-114
A rapid, specific reversed phase HPLC method has been developed for simultaneous determination of olanzapine and fluoxetine
in their formulations. Chromatographic separation of these two pharmaceuticals was carried out on an Inertsil C18 reversed phase column (150 mm × 4.6 mm, 5 μm) with a 40:30:30 (v/v/v) mixture of 9.5 mM sodium dihydrogen phosphate (pH adjusted to 6.8 ± 0.1 with triethylamine), acetonitrile and methanol as
mobile phase. The flow rate 1.2 mL min−1 and the analytes are monitored at 225 nm. Paroxetine was used as internal standard. The assay results were linear from 25
to 75 μg mL−1 for olanzapine (r
2 ≥ 0.995) and 100–300 μg mL−1 for fluoxetine (r
2 ≥ 0.995), showed intra- and inter-day precision less than 1.0%, and accuracy of 97.7–99.1% and 97.9–99.0%. LOQ was 0.005
and 0.001 μg mL−1 for olanzapine and fluoxetine, respectively. Separation was complete in less than 10 min. Validation of the method showed
it to be robust, precise, accurate and linear over the range of analysis. 相似文献