共查询到20条相似文献,搜索用时 46 毫秒
1.
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
2.
A simple reversed-phase high-performance liquid chromatographic (HPLC) method has been developed for the simultaneous determination
of the antiepileptic drugs (AEDs) zonisamide (ZNS), primidone (PRI), lamotrigine (LTG), phenobarbital (PB), phenytoin (PHT),
oxcarbazepine (OXC), and carbamazepine (CBZ) and two of their active metabolites, monohydroxycarbamazepine (MHD) and carbamazepine
10,11-epoxide (CBZE) in human plasma. Plasma (100 μL) was pretreated by deproteinization with 300 μL methanol containing 20 μg mL−1 propranolol hydrochloride as internal standard. HPLC was performed on a C8 column (4.6 mm × 250 mm; particle size 5 μm) with methanol–acetonitrile–0.1% trifluoroacetic acid, 235:120:645 (v/v), as mobile phase at a flow rate of 1.5 mL min−1. ZNS, OXC, and CBZ were monitored by UV detection at 235 nm, and PRI, LTG, MHD, PB, PHT, and CBZE by UV detection at 215 nm.
Relationships between response and concentration were linear over the concentration ranges 1–80 μg mL−1 for ZNS, 5–50 μg mL−1 for PRI, 1–25 μg mL−1 for LTG, 1–50 μg mL−1 for MHD, 5–100 μg mL−1 for PB, 1–10 μg mL−1 for CBZE, 0.5–25 μg mL−1 for OXC, 1–50 μg mL−1 for PHT, and 1–25 μg mL−1 for CBZ. Intra-day and inter-day reproducibility were adequate (coefficients of variation were ≤11.6%) and absolute recovery
ranged from 95.2 ± 6.13 to 107.7 ± 7.76% for all the analytes; for the IS recovery was 98.69 ± 1.12%. The method was proved
to be accurate, reproducible, convenient, and suitable for therapeutic monitoring of the nine analytes. 相似文献
3.
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
4.
Summary A high-performance liquid chromatographic method, with 9-anthryldiazomethane as derivatizing agent, has been developed for
the simultaneous determination ofN-carbamoyl aspartate andl-dihydroorotate in serum. Sample preparation for 1 mL serum was by simple liquid-liquid extraction and then derivatization.
The compounds were separated on a Luna C18(2) column by use of a gradient prepared from acetonitrile and 10 mM sodium acetate
buffer, pH 6.0, and fluorimetric detection was performed at excitation and emission wavelengths of 365 nm and 412 nm, respectively.
The response was found to be linearly dependent on concentration between 0.8 and 60 μg mL−1 forl-dihydrooratate and between 0.9 and 90 μg mL−1 forN-carbamoyl aspartate; the mean recovery rates were 50 and 51%, respectively. The limits of detection and quantification were
0.33 μg mL−1 and 0.6 μg mL−1, respectively, forl-dihydroorotate and 0.4 μg mL−1 and 0.7 μg mL−1 forN-carbamoyl aspartate. This method can be used to assess accumulation ofN-carbamoyl aspartate andl-dihydroorotate in body fluids in situations where cellular pyrimidine de novo synthesis is impaired. 相似文献
5.
Summary A high-performance liquid chromatographic method with amperometric detection has been developed for the determination of levels
of clozapine (CLZ) and its active metabolite N-desmethylclozapine (DMC) in human plasma. The analysis was performed on a 5
μm C8 reversed phase column (150×4.6 mm i.d.), with acetonitrile-phosphate buffer (pH 3.5), as the mobile phase. The detection
voltage was +800 mV and the cell and column temperature were 50°C. Linear responses were obtained between 2 ng mL−1 and 100 ng mL−1. Absolute recovery for both clozapine and desmethylclozapine exceeded 88% and the detection limit was 1 ng mL−1. Repeatability, intermediate precision and accuracy were satisfactory. The method, which is rapid, sensitive and selective,
has been applied to therapeutic drug monitoring in schizophrenic patients following administration of Leponex? tablets. In 21 patients in steady state at a mean daily clozapine dosage of 358 mg (ranging from 150 to 500 mg day−1), clozapine levels averaged 379 ng mL−1 (ranging from 102 to 818 ng mL−1) and DMC levels averaged 233 ng mL−1 (ranging from 70 to 540 ng mL−1). The method requires only a very small amount of plasma (100 μL), and thus it is suitable for pharmacokinetic studies, as
well as for therapeutic drug monitoring. 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.
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
8.
Guanidinoacetate methyltransferase deficiency is a recently discovered inborn defect of creatine biosynthesis which reduces
serum creatinine concentrations to as low as 0.58 μg mL−1 (or 0.00058 μg mL−1 after 1,000-fold dilution). To measure ultra trace levels of creatinine in diluted samples, molecularly imprinted solid-phase
extraction (MISPE) and molecularly imprinted polymer (MIP) sensor techniques have been found to be inadequate. A combination
of these techniques (i.e. MISPE hyphenated with use of an MIP-sensor), reported in this paper, has been found to be highly
suitable for direct assay of creatinine in highly diluted human blood serum without complicated pretreatment of the sample.
The proposed technique has the potential to enhance the sensitivity of creatinine measurement from μg mL−1 to ng mL−1 in highly dilute aqueous samples in which the concentrations of interfering constituents are reduced to negligible levels.
In this work the sensitivity to creatinine was found to be improved compared with that of the MIP-sensor method alone (limit
of detection, LOD, 0.00149 μg mL−1). After preconcentration by MISPE and use of the sensor the detection limit for creatinine was as low as 0.00003 μg mL−1 (RSD = 0.94%, S/N = 3; 50-fold preconcentration factor) in aqueous samples. 相似文献
9.
Dian-Lei Wang Yan Liang Lin Xie Tong Xie X. T. Wang Sen Yu Guang-Ji Wang Xiao-Dong Liu 《Chromatographia》2008,67(3-4):219-224
To evaluate the pharmacokinetics of a novel analogue of ginkgolide B, 10-O-dimethylaminoethylginkgolide B (XQ-1) in rat plasma in pre-clinical studies, a sensitive and specific liquid chromatographic
method with electrospray ionization mass spectrometry detection (LC–ESI–MS) was developed and validated. After a simple extraction
with ethyl acetate, XQ-1 was analyzed on a Shim-pack C18 column with a mobile phase of a mixture of 1 μmol L−1 ammonium acetate containing 0.02% formic acid and methanol (55:45, v/v) at a flowrate of 0.3 mL min−1. Detection was performed in selected ion monitoring (SIM) mode using target ions at [M + H]+
m/z 496.05 for XQ-1 and m/z 432.10 for the internal standard (lafutidine). Linearity was established for the concentration range from 2 to 1,000 ng mL−1 . The extraction recoveries ranged from 86.0 to 89.9% in plasma at concentrations of 5, 50, and 500 ng mL−1. The lower limit of quantification was 2 ng mL−1 with 100 μL plasma. The validated method was successfully applied to a pharmacokinetic study after intragastic administration
of XQ-1 mesylate in rats at a dose of 20 mg kg−1. 相似文献
10.
Koryagina NL Savelieva EI Khlebnikova NS Goncharov NV Jenkins RO Radilov AS 《Analytical and bioanalytical chemistry》2006,386(5):1395-1400
A novel procedure has been developed for determination of fluoroacetic acid (FAA) in water and biological samples. It involves
ethylation of FAA with ethanol in the presence of sulfuric acid, solid-phase microextraction of the ethyl fluoroacetate formed,
and subsequent analysis by GC-FID or by GC-MS in selected-ion-monitoring mode. The detection limits for FAA in water, blood
plasma, and organ homogenates are 0.001 μg mL−1, 0.01 μg mL−1, and 0.01 μg g−1, respectively. The determination error at concentrations close to the detection limit was less than 50%. For analysis of
biological samples, the approach has the advantages of overcoming the matrix effect and protecting the GC and GC-MS systems
from contamination. Application of the approach to determination of FAA in blood plasma and organ tissues of animals poisoned
with sodium fluoroacetate reveals substantial differences between the dynamics of FAA accumulation and clearance in rabbits
and rats. 相似文献
11.
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
12.
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
13.
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
14.
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
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.
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
17.
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
18.
Summary A simple, rapid and accurate, routine-HPLC method is described for simultaneous determination of acetaminophen, caffeine and
chlorpheniramine maleate in a new tablet formulation Chromatographic separation of the three pharmaceuticals was achieved
on a Hypersil CN column (150×5.0 mm, 5 μm) using a mobile phase comprising a mixture of acetonitrile, an ion-pair solution
and tetrahydrofuran (13:14:87, v/v,pH4.5). The flow-rate was changed from 1.0 mL min−1 (in 0≈7.5 min) to 1.8 mL min−1 (after 3.5 min). was complete in <10 min. The method was validated for system suitability, linearity, accuracy, precision,
limits of detection and quantitation, and robustness. Linearity, accuracy and precision were found to be acceptable over the
ranges 31.6≈315.8 μg mL−1 for acetaminophen, 9.5≈94.6 μg mL−1 for caffeine and 1.4≈13.8 μg mL−1 for chlorpheniramine maleate. 相似文献
19.
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
20.
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