A simple and sensitive method was developed for the determination of three nonsteroidal anti-inflammatory drugs (NSAIDs)—ibuprofen, naproxen and fenbufen in human plasma. The method involved in column liquid chromatographic separation and chemilumenescence (CL) detection based on the CL reaction of NSAIDs, potassium permanganate (KMnO4) and sodium sulfite (Na2SO3) in sulfuric acid (H2SO4) medium. The chromatographic separation was carried out using a reversed-phase C18 column, which allowed the selective determination of the three medicines in the complicated samples. The special features of the CL detector provided lower LOD for determination than that of existing chromatographic alternatives. The results indicated that the linear ranges were 0.01–10.0 μg mL−1 for ibuprofen, 0.001–1.0 μg mL−1 for naproxen, and 0.01–10.0 μg mL−1 for fenbufen. The limits of detection were 0.5 ng mL−1 for ibuprofen, 0.05 ng mL−1 for naproxen and 0.5 ng mL−1 for fenbufen (S/N = 3). All average recoveries were in the range of 90.0–102.3%. Finally, the method had been satisfactorily applied for the determination of ibuprofen, naproxen and fenbufen in human plasma samples.
相似文献A rapid, sensitive, and specific reverse phase high performance liquid chromatography with diode array detection procedure for the simultaneous determination of abacavir, efavirenz and valganciclovir in spiked human serum is described. Separation was performed on a 5 μm Waters Spherisorb column (250 × 4.6 mm ID) with acetonitrile: methanol:KH2PO4 (at pH 5.00) (40:20:40 v/v/v) isocratic elution at a flow rate of 1.0 mL min−1. Calibration curves were constructed in the range of 50–30,000 ng mL−1 for abacavir and efavirenz, and 10–30,000 ngmL−1 for valganciclovir in serum samples. The limit of detection and limit of quantification concentrations of the HPLC method were 3.80 and 12.68 ng mL−1 for abacavir, 2.61 and 8.69 ng mL−1 for efavirenz, 1.30 and 4.32 ng mL−1 for valganciclovir. The method has been applied, without any interference from excipients or endogenous substances, for the simultaneous determination of these three compounds in human serum.
相似文献In the present studies, a simple rapid ultra performance liquid chromatography (UPLC) method with UV detection for the simultaneous determination of cortisol, cortisone and 6β-hydroxycortisol in human urine was developed. The three analytes and the internal standard dexamethasone were separated on a Waters Acquity UPLC-Tunable UV system with an Acquity UPLC BEH C18 column (50 × 2.1 mm ID, 1.7 μm) using a gradient elution of methanol and water (containing 0.01% formic acid) with a run time of 7 min. The method was accurate and precise, over the ranges of 5–200 ng mL−1 for cortisol, and 10–1,000 ng mL−1 for both cortisone and 6β-hydroxycortisol, and showed good linearity (r 2 > 0.999). This method was applied for the measurement of cortisol, cortisone and 6β-hydroxycortisol in samples collected over different periods as a tool to assess the activity of CYP3A and 11β-hydroxysteroid dehydrogenase type 2 enzymes.
相似文献The objective of the current study was the development and subsequent validation of a simple, sensitive, precise and stability-indicating reversed-phase HPLC method for the determination of ciprofloxacin HCl in pharmaceutical dosage forms in the presence of its potential impurities. The chromatographic separation of ciprofloxacin HCl and its related compounds was achieved on an Inertsil ODS3 column using UV detection. The optimized mobile phase consisted of phosphoric acid solution: acetonitril. The proposed method provided linear responses within the concentration range 250–750 μg mL−1 for ciprofloxacin HCl and 0.5–1.5 μg mL−1 for its related compounds. LOD and LOQ values for the active substance were 5.159 and 15.632 μg mL−1, respectively. Correlation coefficients (r) of the regression equations for the impurities were greater than 0.99 in all cases. The precision of the method was demonstrated using intra- and inter-day assay RSD% values which were less than 1% in all instances. No interference from any components of pharmaceutical dosage forms or degradation products was observed.
相似文献A simple, specific and sensitive liquid chromatographic method has been developed for the assay of ketorolac in human plasma and urine. The clean-up of plasma and urine samples were carried out by protein precipitation procedure and liquid–liquid extraction, respectively. Separation was performed by a Waters sunfire C18 reversed-phase column maintained at 35 °C. The mobile phase was a mixture of 0.02 M phosphate buffer (pH adjusted to 4.5 for plasma samples and to 3.5 for urine samples) and acetonitrile (70:30, v/v) at a flow rate of 1.0 mL min−1. The UV detector was set at 315 nm. Nevirapine was used as an internal standard in the assay of urine sample. The method was validated over the concentration range of 0.05–8 and 0.1–10 μg mL−1 for ketorolac in human plasma and urine, respectively. The limits of detection were 0.02 and 0.04 μg mL−1 for plasma and urine estimation at a signal-to-noise ratio of 3. The limits of quantification were 0.05 and 0.1 μg mL−1 for plasma and urine, respectively. The extraction recoveries were found to be 99.3 ± 4.2 and 80.3 ± 3.7% for plasma and urine, respectively. The intra-day and inter-day standard deviations were less than 0.5. The method indicated good performance in terms of specificity, linearity, detection and quantification limits, precision and accuracy. This assay demonstrated to be applicable for clinical pharmacokinetic studies.
相似文献A sensitive, simple, and accurate method for determination and pharmacokinetic study of ferulic acid and isoferulic acid in rat plasma was developed using a reversed-phase column liquid chromatographic (RP-LC) method with UV detection. Sample preparations were carried out by protein precipitation with the addition of methanol, followed by evaporation to dryness. The resultant residue was then reconstituted in mobile phase and injected into a Kromasil C18 column (250 × 4.6 mm i.d. with 5 μm particle size). The mobile phase was methanol-1% formic acid (33:67, v/v). The calibration plots were linear over the range 5.780–5780 ng·mL−1 for ferulic acid and 1.740–348.0 ng·mL−1 for isoferulic acid. Mean recoveries were 85.1% and 91.1%, respectively. The relative standard deviations (RSDs) of within-day and between-day precision were not above 15% for both of the analytes. The limits of quantification were 5.780 ng·mL−1 for ferulic acid and 1.740 ng·mL−1 for isoferulic acid. This RP-LC method was used successfully in pharmacokinetic studies of ferulic acid and isoferulic acid in rat plasma after intravenous injection of Guanxinning Lyophilizer.
相似文献A sensitive high performance liquid chromatographic method has been developed and validated for the determination of proparacaine in human aqueous humour. The procedure involved extraction of proparacaine from aqueous humour with cyclohexane. The separation was achieved using a Bondesil C8 (250 × 4.6 mm i.d., particle size 5 μm) analytical column with a mobile phase consisted of acetonitrile and sodium dihydrogen phosphate (pH 3.0, 20 mM) (30:70, v/v). Proparacaine and lidocaine (internal standard, IS) detection was performed by UV–Vis detector at 220 nm. The retention times for proparacaine and IS were 12.01 and 5.58 min, respectively. HPLC–UV–Vis method was linear in the range of 75–4,000 ng mL−1. The limit of detection (LOD) was 25 ng mL−1 and the limit of quantification (LOQ) of proparacaine was found to be 75 ng mL−1 (RSD ≤ 15%, n = 6). In intra- and inter-day precision and accuracy analysis, the relative standard deviation was found to be in the range of 0.96 and 7.98%, the bias values were 0.64 and 3.33%. Recovery of proparacaine from human aqueous humour was 99.98% at 500 ng mL−1. Proparacaine solutions were stable at least 6 months at +4 and −20 °C. Proparacaine levels of aqueous humour in fifteen volunteers’ were in the range of 80.21 and 459.00 ng mL−1. According to system suitability tests and Shewhart’s quality control charts the proparacaine responses were in the acceptance ranges. Developed method was providing a sufficient quality at least over 3 months for determination of proparacaine in human aqueous humour.
相似文献A sensitive and simple HPLC method for simultaneous determination of PAC-1 (first procaspase-activating compound), phenol red, and permeability markers (carbamazepine and furosemide) in perfusion samples was developed and validated to assess intestinal absorption of PAC-1 using single-pass intestinal perfusion technique (SPIP) in rats. The chromatographic separation was carried out on a Kromasil C18 column (150 mm × 4.6 mm, 5 μm) with acetonitrile–methanol–30 mmol L−1 phosphate buffer (pH 3.0, 25:10:65, v/v/v) as mobile phase at a flow rate of 1.0 mL min−1, and the wavelength of the UV detector was set at 281 nm. The calibration curves were linear in the ranges of 2.40–48.0 μg mL−1 for PAC-1; 3.60–72.0 μg mL−1 for carbamazepine; 3.20–64.0 μg mL−1 for furosemide, and 4.80–96.0 μg mL−1 for phenol red (r > 0.999). Both the intra- and inter-day precisions (RSD%) of all analytes were less than 6.8 % at three concentration levels, while accuracy ranged from 95.4 to 104.5 %. Data obtained in all method validation studies indicated that the method was suitable for the intended purpose. The effective permeability values (P eff) considering water flux with the help of non-permeable marker phenol red was calculated to be 0.42 × 10−4, 0.62 × 10−4, 0.32 × 10−4 cm s−1 for PAC-1; 0.72 × 10−4, 0.77 × 10−4, 0.52 × 10−4 cm s−1 for carbamazepine; 0.20 × 10−4, 0.16 × 10−4, 0.12 × 10−4 cm s−1 for furosemide in duodenum, jejunum and ileum, respectively. The P eff value can be increased by co-perfusion with verapamil, indicating that absorption of PAC-1 is efficiently transported by P-glycoprotein (P-gp) in the gut wall.
相似文献A fast gas chromatographic–mass spectrometric (GC–MS) method is proposed for pesticide multiresidue analysis of apples. The QuEChERS method was used for sample preparation. GC–MS analysis was performed with a PTV, an autoinjector, and a quadrupole benchtop MS detector. Electron-impact ionization (70 eV) was used with two modes of selected ion monitoring. Compounds were separated under temperature-programmed conditions on a narrow-bore diphenyldimethylsiloxane column. In one chromatographic run 61 pesticides of different chemical classes, and triphenyl phosphate as internal standard, were determined in 11 min. Calibration was performed with matrix-matched standard solutions and response to the pesticides was a linear function of concentration in the range 1–500 ng mL−1 (equivalent to 1–500 μg kg−1 in real samples). High values of the determination coefficients (R 2; 0.9900–1.0000) were obtained for most of the pesticides. Limits of detection and quantification were determined. When the method was used for analysis of pesticide residues in real samples, five pesticides were detected at concentrations in the range 1.00–21.47 μg kg−1. Repeatability of measurements, expressed as relative standard deviations of absolute peak areas, normalized relative to TPP, and of the concentrations determined, met the EU criterion of RSD ≤ 20%. Use of the internal standard moderately improved quantitative results.
相似文献This paper presents an analytical method for the simultaneous determination of zoalene and its metabolite 3-amino-5-nitro-o-toluamide (3-ANOT) in chicken muscle and liver by solid phase extraction and UPLC–MS-MS operated in the positive and negative ionization switching mode. Samples were extracted with phosphate buffer solution and purified with OASIS™ HLB cartridge after pH adjustment. The determination was carried out using UPLC–MS-MS on a Waters Acquity BEH C18 column with 0.1% formic acid in water/acetonitrile as mobile phase with gradient elution. The linearity of the analytical response across the studied range of concentrations (2.0–1,000 μg L−1) was excellent, obtaining correlation coefficients higher than 0.999. Matrix effects had been investigated for zoalene and 3-ANOT. Recovery studies were carried out on spiked chicken muscle and liver blank samples, at four concentration levels (50, 1,500, 3,000, and 4,500 μg kg−1 for chicken muscle and 50, 3,000, 6,000, and 9,000 μg kg−1 for chicken liver) performing six replicates at each level. Mean recoveries of 77.9–94.2% with CVs of 3.2–8.7% were obtained. The method demonstrated to be suitable for the simultaneous determination of zoalene and 3-ANOT in chicken tissues.
相似文献A simple, fast and sensitive LC–MS/MS method was developed and validated for the simultaneous determination of the concentrations of temsirolimus and its major metabolite, sirolimus, in human whole blood. The blood sample (100 μL) after adding temsirolimus-d7 and sirolimus-d3 internal standards was precipitated with 0.200 mL of methanol/0.300 M zinc sulfate (70/30, v/v), then analyzed by a Shimatzu LC system coupled to a Sciex API-5000 mass spectrometer. The chromatographic separation was carried out on a BDS Hypersil C8 column (50 × 3.0 mm, 5 μm) at 50 °C with a mobile phase composed of methanol/water/formic acid (72/28/0.1) (v/v/v) containing 2.50 mM ammonium acetate. Mass spectrometric detection was performed using electrospray positive ionization with multiple reaction monitoring mode. This method was validated from 0.250 to 100 ng mL−1 for temsirolimus and 0.100 to 40.0 ng mL−1 for sirolimus. The lower limits of quantitation were 0.25 ng mL−1 for temsirolimus and 0.1 ng mL−1 for sirolimus. The intra-day and inter-day precisions (CV %) of spiked quality control (QC) samples were less than 10.4 and 9.6 %, respectively. The accuracies as determined by the relative error for QC samples were less than 12.1 % for intra-day and 7.3 % for inter-day. No significant matrix effect was observed. This method has been successfully applied to analyze clinical pharmacokinetic study samples. The assay reproducibility was also demonstrated by using incurred samples.
相似文献A rapid and specific high-performance liquid chromatographic method coupled with electrospray ionization mass spectrometric detection has been developed and validated for identification and quantification of wogonin and oroxylin A in rat plasma. Wogonin, oroxylin A, and diazepam (internal standard) were extracted from plasma samples by liquid–liquid extraction with ethyl acetate. Chromatographic separation was achieved on a C18 column with acetonitrile–0.6% aqueous formic acid 35:65 (v/v) as mobile phase at a flow rate of 0.2 mL min−1. Detection was performed with a single-quadrupole mass spectrometer in selected-ion-monitoring (SIM) mode. Linearity was good within the concentration range 14.4–360 ng mL−1 for wogonin and 10.8–271 ng mL−1 for oroxylin A; the correlation coefficients (r 2) were 0.9999. The intra-day and inter-day precision, as RSD, was below 12.4%, and accuracy ranged from 81.1 to 111.9%. The lower limit of quantification was 14.4 ng mL−1 for wogonin and 10.8 ng mL−1 for oroxylin A. This method was successfully used in the first pharmacokinetic study of wogonin and oroxylin A in rat plasma after oral administration of the active fraction from Xiao-xu-ming decoction.
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