共查询到20条相似文献,搜索用时 31 毫秒
1.
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
2.
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
3.
Summary An HPLC method with fluorescence detection is presented for the analysis of enrofloxcin (ENR) and ciprofloxacin (CIP) in chicken
tissue using sarafloxacin (SAR) as internal standard. Tissue sample preparations were carried out by adding a phosphate buffer
(pH 7.4, 0.1 M), followed by extraction with trichloromethane. Fluoroquinolones were separated on a reversed-phase column
with a mobile phase of aqueous phosphate buffer-acetonitrile (80:20). The concentrations of CIP, ENR and SAR eluted off the
column, with retention times of 2.28, 3.30 and 4.40, respectively, were monitored by fluorescence detection atλ
ex 338 andλ
em 425 nm. The detection limit was 32 ng g−1 for CIP and 10 ng g−1 for ENR. The standard curves were linearly related to concentration in the range of 1 to 2000 ng g−1. Recovery was determinated as 91.3% and 78.3% for ENR and CIP, respectively. The measurement of the tissue levels of ENR
and CIP in the chicken after oral administration confirmed the utility of the proposed analytical methodology. 相似文献
4.
S. Perez-Olivan C. Solans M. A. García I. Pinilla F. Honrubia M. A. Bregante 《Chromatographia》2000,51(1-2):25-28
Summary A sensitive HPLC assay for the determination of grepafloxacin (GRE) in biological samples is described. Sample preparations
were carried out by adding phosphate buffer (pH 7.4, 0.1M), followed by extraction with trichloromethane. GRE and the internal
standard, enrofloxacin (ENR), were separated on a reversed-phase column using an aqueous phosphate solution-acetonitrile (78∶22)
mobile phase. The concentrations of ENR and GRE eluting of the column with retention times of 2.55, and 4.90 min, respectively
were monitored by fluorescence atλ
ex 338 andλ
em 425 nm. The method was shown to be linear from 5 to 4000 ng mL−1. The detection and quantitation limits were 5 and 10 ng mL−1, respectively. Mean recovery was determined as 90%. Inter- and intra-assay precisions were 3.0% and 3.5% respectively. The
method was applied to the determination of GRE in plasma samples collected during clinical pharmacokinetic studies. 相似文献
5.
López-Flores J Fernández-de Córdova ML Molina-Díaz A 《Analytical and bioanalytical chemistry》2007,388(8):1771-1777
A flow injection–solid-phase spectroscopy (FI-SPS) system implemented with photochemically induced fluorescence (PIF) is described
for the rapid and very sensitive determination of reserpine in biological fluids and pharmaceutical formulations. An intensively
fluorescent photoproduct is in-line generated, retained on C18 silica gel in the detection area and monitored at 394/489 nm (λ
ex/λ
em). After the establishment of the appropriate working variables, the system is calibrated at two different injection volumes,
100 and 800 μL, achieving detection limits of 0.33 and 0.05 ng mL−1, respectively. The RSD for reserpine at 2 ng mL−1 (800 μL) was 1.5% (n = 10). The sampling rates were 46 and 43 h−1 for each injection volume, respectively. The potential interference of some common species coexisting with reserpine in the
analysed samples was also studied. The procedure was successfully applied to commercial formulations, urine and serum without
any previous treatment of samples. Recoveries ranged from 94.9 to 100.2%. 相似文献
6.
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
7.
Jun Wen Zhenyu Zhu Zhanying Hong Yiwen Wu Yan Fei Mei Lin Guorong Fan Yutian Wu 《Chromatographia》2007,66(1-2):37-41
A cheap, simple and rapid sample preparation method has been developed for quantification of ulifloxacin, the active metabolite
of prulifloxacin in human plasma, by HPLC with fluorescence detection using lemefloxacin as the internal standard. One-step
protein precipitation with 10% perchloric acid (2:1, v/v) on a 200 μL sample was used. The separation was performed at 30 °C on a C18 column using an eluent of acetonitrile-0.5%
triethylamine buffer. The compounds were monitored at λ
ex of 280 nm, λ
em of 425 nm. The calibration curve for ulifloxacin in human plasma was linear over the range 0.01–1.00 μg mL−1. The lower limit of quantification is 0.01 μg mL−1. The intra- and inter-day precision ranged from 3.0 to 6.7%, respectively. The method had been used for clinical pharmacokinetic
studies of prulifloxacin formulation product after oral administration to healthy volunteers.
Jun Wen and Zhenyu Zhu have equal contribution to this work. 相似文献
8.
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
9.
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
10.
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
11.
Summary Gas chromatography with electron capture detection (GC-ECD) for the analysis of methylmercury choloride (MMC) using a packed
column and a capillary column has been investigated. The columns were 2% silicone OV-227 Uniport HP glass column and a DB-17
capillary column, each pretreated by about ten injections of HBr-methanol solution. MMC was separated as a sharp peak by the
HBr-teated column and determined directly by ECD without derivatisation. The mass spectrum of MMC indicated that halide exchange
from chloride to bromide proceeded during separation. The minimum detectable concentrations were approximately 5 ng mL−1 on the packed column, and 2 ng mL−1 on the capillary. Calibration curves showed good linearity between 5–200 ng mL−1 for the packed column, and between 2–200 ng mL−1 for the capillary. Relative standard deviations of peak areas were 0.95% for the packed column and 0.43% for the capillary
at the level of 100 ng mL−1 in both cases. The column treatment technique was applicable to determination of methylmercury in fish samples. 相似文献
12.
M. A. Campanero B. Calahorra E. García-Quetglás M. Escolar J. Honorato 《Chromatographia》1998,48(7-8):555-560
Summary A sensitive liquid chromatographic assay for the quantitative determination of the opioid analgesic tramadol and its active
metabolite is described. Fluconazole was used as internal standard. The assay involved a singletert-butyl methyl ether extraction and LC analysis with fluorescence detection. Chromatography was at 30°C pumping an isocratic
mobile phase of acetonitrile-water (19∶81, v/v) containing 0.06M NaH2PO4 and 0.05M triethylamine, adjusted to pH 7.90, at 1 mL min−1 through a reversed-phase, 250×4 mm base-stable column. The limit of quantitation of tramadol and its active metabolite was
1 ng mL−1, only 0.5 mL plasma sample was required for the determination. The calibration curve was linear from 1–1000 ng mL−1. Intra and inter-day precision (C.V.) did not exceed 10%. Mean recoveries of 96.38% for tramadol and 96.62% forO-demethyltramadol with CVs of 0.43% and 1.46% were obtained. Applicability of the method was demonstrated by a pharmacokinetic
study on normal volunteers who received 100 mg tramadol intravenously. 相似文献
13.
A pre-column derivatized high-performance liquid chromatographic (HPLC) method with ultraviolet-visible detection was developed
to measure the concentrations of spectinomycin in fermentation broth. Derivatization reagents, 2,4-dinitrophenylhydrazine
in acetonitrile (5 mg mL−1) and trifluoroacetic acid in acetonitrile (0.8 mol L−1), were added to an aliquot of the fermentation broth, and the mixture was incubated for 60 min at 70°C. The resulting derivative
was separated from other compounds by isocratic elution in a reversed-phase column Zorbax SB-C18 (250 mm × 4.6 mm, 5 μm).
Mobile phase consisted of acetonitrile, tetrahydrofuran, and water (φ
r = 40: 35: 25) and the flow rate was 1.0 mL min−1. The detection wavelength was 415 nm. The standard curve for spectinomycin sulfate was linear with correlation coefficients
of 0.9997 in the range of 25 μg mL−1 to 600 μg mL−1. The relative standard deviation values ranged from 0.43 % to 2.18 % depending on the concentration of samples. The average
recovery was 101.5 %. The limit of detection was 50 ng mL−1. 相似文献
14.
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
15.
M. A. Raggi R. Mandrioli C. Sabbioni N. Ghedini S. Fanali V. Volterra 《Chromatographia》2001,54(3-4):203-207
Summary An improved HPLC method with electrochemical detection has been developed for the determination of olanzapine and its main
metabolite, desmethylolanzapine, in human plasma. Chromatographic separation and analysis were performed on a C8 reversed-phase column with a mixture of methanol, acetonitrile, and pH 3.7 phosphate buffer as mobile phase; 2-methylolanzapine
was used as internal standard. Careful pretreatment of the plasma samples was implemented by means of solid phase extraction
(SPE).
Response was linearly dependent on concentration and precision was satisfactory over the concentration range 0.5–75.0 ng mL−1 for both analytes. The limit of detection was 0.2 ng mL−1 for both analytes. Application to plasma samples of patients treated with Zyprexa tablets gave good results. Because of its
sensitivity and selectivity, and the need for small plasma samples, this method seems to be a useful tool for clinical monitoring. 相似文献
16.
Christine Farthing Don Farthing Donald F. Brophy Terri Larus Lena Maynor Itaf Fakhry Todd W. B. Gehr 《Chromatographia》2008,67(5-6):365-368
A simple high-performance liquid chromatographic (HPLC) method was developed for the simultaneous determination of cefepime
and cefazolin in human plasma and dialysate. For component separation, the method utilized a C18 column with an aqueous mobile phase of dibasic potassium hydrogen phosphate (pH 7.0) and methanol gradient at a flow rate
of 1 mL min−1. The method demonstrated linearity from 2.0 to 100.0 μg mL−1 (r > 0.999) with detection limit of 1 μg mL−1 for both cefepime and cefazolin. The method was utilized for evaluation of plasma and dialysate samples in a clinical study
evaluating the dialyzer clearance of cefepime and cefazolin using high-flux hemodialysis with varying blood flow rates in
chronic kidney failure patients undergoing hemodialysis and peritoneal dialysis treatment. 相似文献
17.
Summary Clenbuterol has been determined in urine by solidphase extraction on a C18 cartridge, diazotization of the eluate with nitrite, coupling of the diazonium ion with 1-(naphthyl)ethylenediamine, and
separation of the azo dye formed by HPLC with a C18 column and a micellar mobile phase containing 0.1 M sodium dodecyl sulphate, 12%n-butanol and 0.05 M citrate buffer, pH 3. Recoveries higher than 90% were obtained by mixing the samples with a 20% 0.2 M
NaOH before extraction. Limits of detection of 51 and 6.7 ng L−1 were obtained with spectrophotometric and thermal lens spectrometric detection, respectively; respective repeatabilities
were 3.1% (5 μg mL−1) and 5.6% (0.16 μg mL−1). 相似文献
18.
C. Flores-Pérez H. Juárez-Olguín J. Flores-Pérez B. Ramírez-Mendiola J. Bobadilla Chávez 《Chromatographia》2005,62(7-8):373-377
The aim of the present study was to develop a simple method to measure plasma levels of propafenone by liquid chromatography
with a C18 reverse-phase column and fluorescence detection, without previous derivatization of the sample. Linearity was assessed
in the range from 50 to 1000 ng mL−1 and had a correlation coefficient of 0.999. The inter- and intra-day coefficients of variation were below 5%. The limits
of detection and quantification were 15 ng mL−1 and 50 ng mL−1, respectively. Drug levels were determined satisfactorily in two patients. A simple and reliable method was developed, especially
useful in children with heart failure under treatment with propafenone. 相似文献
19.
CdTe nanocrystals (CdTe NCs) were achieved by reaction of CdCl2 with KHTe solution and were capped with sodium mercaptoacetate. The product was detected by transmission electron microscopy
(TEM), high-resolution transmission electron microscopy (HRTEM), energy dispersive spectroscopy (EDS), fluorescence spectra,
ultraviolet-visible spectra and X-ray diffraction (XRD). The CdTe NCs are of cubic structure and the average size is about
5 nm. The fluorescence quantum yield of CdTe NCs aqueous solution increased from 37% to 97% after 20 d under room light. The
maximum λ
em of fluorescence changed from 543 nm to 510 nm and the blue shift was 33 nm. CdTe NCs aqueous solution can be steady for at
least 10 months at 4 in° a refrigerator. The resonance Rayleigh scattering (RRS) of CdTe NCs in the aqueous solution was investigated.
The maximum scattering peak was located at about 554 nm. The interactions of CdTe NCs with amikacin sulfate (AS) and micronomicin
sulfate (MS) were investigated respectively. The effects of AS and MS on fluorescence and RRS of CdTe NCs were analyzed. It
was found that AS and MS quenched the photoluminescence of CdTe NCs and enhanced RRS of CdTe NCs. Under optimum conditions,
there are linear relationships between quenching intensity (F
0-F), intensity of RRS (I-I
0) and concentration of AS and MS. The detection limits (3б) of AS and MS are respectively 3.4 ng·mL−1 and 2.6 ng·mL−1 by the fluorescence quenching method, and 15.2 ng·mL−1 and 14.0 ng·mL−1 by the RRS method. The methods have high sensitivity, thus CdTe NCs may be used as fluorescence probes and RRS probes for
the detection of aminoglycoside antibiotics.
Supported by the National Natural Science Foundation of China (Grant No. 20475045) 相似文献
20.
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