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1.
Summary A rapid and simple liquid-chromatographic method has been developed for on-line quantification of amphetamine in biological
fluids. Untreated samples (20 μL) are injected directly into the chromatographic system and purified on a 20 mm×2.1 mm i.d.
pre-column packed with 30 μm Hypersil C18 stationary phase. After clean-up the analyte is transferred to the analytical column (125 mm×4 mm i.d., 5 μm LiChrospher
100 RP18) for derivatization and separation using a mixture of acetonitrile and the derivatization reagent (o-phthaldialdehyde andN-acetyl-L-cysteine) as the mobile phase. The experimental conditions for on-line derivatization and resolution of the amphetamine
have been optimized, and the results have been compared with those obtained by derivatizing the analyte in pre-column mode.
The method described has been applied to the determination of amphetamine in plasma and urine. Good linearity and reproducibility
were obtained in the 0.1–10.0 μg mL−1 concentration range, and limits of detection were 25 ng mL−1 and 10 ng mL−1 with UV and fluorescence detection, respectively. The procedure described is very simple and rapid, because no off-line manipulation
of the sample is required; the total analysis time is approximately 8 min. 相似文献
2.
Determination of eight penicillins in serum from cattle and pigs by generic HPLC method 总被引:1,自引:0,他引:1
Summary An HPLC method was developed for determination of amoxicillin, penicillin G, penicillin V, ampicillin, oxacillin, cloxacillin,
nafcillin and dicloxacillin in serum from pigs and cattle. Serum was cleaned up by solid-phase extraction (SPE), ultra-filtered
and derivatised. The method was linear in the range tested up to 2000 ng mL−1 of individual penicillins in serum. Limits of detection were 11–14 ng mL−1. Mean recoveries were 90–103% in the range 20–2000 ng mL−1. The relative repeatability, standard deviation was <10% at 20 ng mL−1 level and <6% in the range 100–2000 ng mL−1. 相似文献
3.
M. A. Raggi C. Sabbioni V. Pucci N. Ghedini N. Calonghi G. Gerra 《Chromatographia》2001,53(7-8):409-413
Summary This study deals with the development of a new HPLC method for the determination of 3-methoxy-4-hydroxyphenylglycol (MHPG),
the main noradrenaline metabolite in human plasma. A Varian reversed-phase column (C8; 250 mm×4.6 mm i.d.; 5 μm particles) was used as the stationary phase and an aqueous solution of citric acid, 1-octanesulfonic
acid, EDTA, and methanol was used as the mobile phase. Coulometric electrochemical detection (ED) was used to obtain the highest
sensitivity. Isolation of MHPG from plasma was accomplished by means of a new solid-phase extraction procedure after a protein
precipitation step. The extraction yield of MHPG from plasma was very high (>97%). Linearity was observed in the 0.5–25 ng
mL−1 concentration range; the limit of detection was 0.2 ng mL−1 and the limit of quantitation was 0.5 ng mL−1. Repeatability (RSD,%) for plasma samples was found to be <3.2% and intermediate precision was <4.3%. The method was applied to the determination
of MHPG in the plasma of healthy subjects under experimentally-induced psychological stress. 相似文献
4.
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
5.
Summary A novel method for the simultaneous determination of twelve water- and fat-soluble vitamins has been established by high-performance
liquid chromatography with diode array detection. The vitamins were analyzed on a μBondapak C18 column (300 × 3.9 mm, 10 μm) with methanol-KH2PO4 buffer (0.1 M, pH 7.0)-water as mobile phase in a gradient. The linearity of calibration graphs was compound-dependent and
the detection limits ranged from 0.02 μg mL−1 to 0.5 μg mL−1. The method was successfully applied to determine vitamins in pharmaceutical preparations. The recoveries were from 95.1%
to 103% and the relative standard deviations were in the range of 0.9% to 4.5%. 相似文献
6.
Summary A rapid and accurate HPLC method is described for the simultaneous determination of acetaminophen, dextromethorphen hydrobromide
and pseudoephedrine hydrochloride in a new cold formulation. Chromatographic separation of the three pharmaceuticals was performed
on a Hypersil CN column (150×5.0 mm, 5 μm) with a mobile phase mixture of an ion-pairing solution, methanol and acetonitrile
(25:57:18, v/v), at a flow rate of 1.0 mL min−1, with detection at 220 nm. Separation was complete in less than 10 min. The method was validated for linearity, accuracy,
precision, limit of quantitation and robustness. Linearity, accuracy, and precision were found to be acceptable over the ranges
of 2.06∼20.6 μg·mL−1 for acetaminophen, 0.202∼2.02 mg·mL−1 for pseudoephedrine hydrochloride and 0.042∼1.06 mg·mL−1 for dextromethorphen hydrobromide. 相似文献
7.
M. A. Raggi R. Mandrioli G. Casamenti V. Volterra C. Desiderio S. Fanali 《Chromatographia》1999,50(7-8):423-427
Summary An HPLC method with fluorescence detection has been developed for the determination of fluoxetine and its main metabolite
norfluoxetine in human plasma. Pretreatment of the biological samples by liquid-liquid extraction was used to improve the
sensitivity of a previously published SPE procedure. The method uses 200 μL plasma and recovery is good for both analytes.
On a C8 column with a mixture of perchlorate buffer and acetonitrile as mobile phase fluoxetine, norfluoxetine and the internal standard
(paroxetine) were eluted in less than 9 min, without interference from the biological matrix. Response for both analytes was
linearly dependent on concentration over the range 2.5–500 ng mL−1, and repeatability (RSD%) was <4%. The limit of detection was 1 ng mL−1 for both fluoxetines. Application to plasma samples from depressed patients treated with fluoxetine gave good results. There
was no interference from other common CNS drugs. This method seems to be a useful tool for clinical monitoring, because it
requires small plasma samples and is highly sensitive and highly selective. 相似文献
8.
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
9.
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
10.
Summary A sensitive HPLC method with marbofloxacin (MAR) as internal standard and fluorescence detection is described for the analysis
of ofloxacin (OFL) enantiomers in plasma samples. Plasma samples were prepared by adding phosphate buffer (pH 7.4, 0.1m), then extracted with trichloromethane.S-OFL,R-OFL, and the internal standard were separated on a reversed-phase column with water-methanol, 85.5∶14.5, as mobile phase.
The concentrations ofS-OFL andR-OFL eluting from the column (retention times 7.5 and 8.7 min, respectively) were monitored by fluorescence detection withλ
ex = 331 andλ
em = 488 nm. The detection and quantitation limits were 10 and 20 ng mL−1, respectively, forS-OFL and 11 and 21 ng mL−1 forR-OFL. Response was linearly related to concentration in the range 10 to 2500 ng mL−1. Recovery was close to 93% for both compounds. The method was applied to determination of the enantiomers of OFL in plasma
samples collected during pharmacokinetic studies. 相似文献
11.
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
12.
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
13.
M. A. Garcia C. Solans J. J. Aramayona S. Rueda M. A. Bregante 《Chromatographia》2000,51(7-8):487-490
Summary An HPLC method with fluorescence detection is presented for the analysis of difloxacin (DIF) and sarafloxacin (SAR) in rabbit
plasma using norfloxacin (NOR) as internal standard (Figure 1). Plasma sample preparations were carried out by adding phosphate
buffer (pH 7.4, 0.1 M), followed by extraction with trichloromethane. Fluoroquinolones were separated on a reversed-phase
column using an aqueous phosphate solution-acetonitrile (82:18) mobile phase. The concentrations of NOR, SAR and DIF eluting
off the column, with retention times of 2.16, 5.60 and 6.20, respectively, were monitored by fluorescence detection atλ
ex 338 andλ
em 425 nm. The quantitation limit was 12 ng mL−1 for SAR and DIF. Standard curves were linearly related to concentration in the range from 1 to 1500 ng mL−1. Recovery was determined as 76% and 70% for SAR and DIF, respectively. Inter-and intraassay coefficients of variation were
less than 6% for all compounds. 相似文献
14.
Summary A rapid, simple, accurate and sensitive liquid chromatographic assay with on-line solid-phase extraction is described for
determination of trovafloxacin in human serum. Samples were deproteinized with acetonitrile and injected on to an NH2 extraction column for sample clean-up. Thereafter, an on-line column-switching system was used for quantitative transfer
of the drug to a C18 analytical column. Separation was performed by ion-pair chromatography and detection was by ultraviolet absorbance at 275
nm. Recovery was 98.5%. The linear range was from 0.25 to 20μg mL−1, with a correlation coefficient of 0.999. Detection limit was 0.1 μg mL−1 from extraction of 25 μL serum. 相似文献
15.
Determination of Aldehydes and Ketones in Fuel Ethanol by High-Performance Liquid Chromatography with Electrochemical Detection 总被引:1,自引:0,他引:1
A. A. Saczk L. L. Okumura M. F. de Oliveira M. V. B. Zanoni N. R. Stradiotto 《Chromatographia》2006,63(1-2):45-51
A new methodology was developed for analysis of aldehydes and ketones in fuel ethanol by high-performance liquid chromatography
(HPLC) coupled to electrochemical detection. The electrochemical oxidation of 5-hydroxymethylfurfural, 2-furfuraldehyde, butyraldehyde,
acetone and methyl ethyl ketone derivatized with 2,4-dinitrophenylhydrazine (DNPH) at glassy carbon electrode present a well
defined wave at +0.94 V; +0.99 V; +1.29 V; +1.15 V and +1.18 V, respectively which are the basis for its determination on
electrochemical detector. The carbonyl compounds derivatized were separated by a reverse-phase column under isocratic conditions
with a mobile phase containing a binary mixture of methanol / LiClO4(aq) at a concentration of 1.0 × 10−3 mol L−1 (80:20 v/v) and a flow-rate of 1.1mL min−1 . The optimum potential for the electrochemical detection of aldehydes-DNPH and ketones-DNPH was +1.0 V vs. Ag/AgCl. The
analytical curve of aldehydes-DNPH and ketones-DNPH presented linearity over the range 5.0 to 400.0 ng mL−1, with detection limits of 1.7 to 2.0 ng mL−1 and quantification limits from 5.0 to 6.2 ng mL−1, using injection volume of 20 μL. The proposed methodology was simple, low time-consuming (15 min/analysis) and presented
analytical recovery higher than 95%. 相似文献
16.
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
17.
M. A. Garcia C. Solans A. Calvo M. Royo E. Hernandez R. Rey M. A. Bregante 《Chromatographia》2002,55(7-8):431-434
Summary A sensitive HPLC method has been developed for determination of ofloxacin (OFL) in biological fluids. Sample preparation was
performed by adding phosphate buffer (pH 7.4, 0.1m) then extraction with trichloromethane. OFL and the internal standard, sarafloxacin (SAR), were separated on a reversed-phase
column with aqueous phosphate solution-acetonitrile, 80∶20, as mobile phase. The fluorescence of the column effluent was monitored
at λex 338 and λem 425 nm. The retention times were 2.66 and 4.24 min for OFL and SAR, respectively, and the detection and quantitation limits
were 8 and 15 ng mL−1, respectively. Plots of response against ofloxacin concentration were linear in the range 8 to 2000 ng mL−1. Recovery was 92.9% for OFL. 相似文献
18.
H. M. Lee C. K. Jeong S. J. Choi B. M. Yoon D. H. Na K. C. Lee H. S. Lee 《Chromatographia》2000,51(5-6):353-356
Summary An automated microbore, liquid chromatographic method with column-switching was developed for the determination of clomipramine
from human plasma samples. After direct injection of samples (60 μL), plasma proteins and clomipramine were separated in size-exclusion
mode using 20% acetonitrile in 20 mM phosphate buffer (pH 7.0) on Capcell Pak MF Ph-1 precolumn (10×4 mm I.D.). By valve switching,
a fraction containing clomipramine was directed to an intermediate column for subsequent main separation on a microbore C18 column (250×1.5 mm I.D.) using 50% acetonitrile in 20 mM phosphate buffer (pH 2.5) at 0.1 mL min−1. The method was advantageous for rapidity (total analysis time: 15 min), reproducibility (C.V.<4.8%), and increased sensitivity
(1 ng mL−1). The linearity of response was good (r
2≥0.999) over the concentration range 1–250 ng mL−1. 相似文献
19.
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
20.
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