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1.
Summary A method for the determination of the food mutagen 2-amino-1-methyl-6-phenylimidazo[4,5- b]pyridine (PhIP) in human hair has been developed and validated. Hair samples (200 mg) were dissolved in NaOH (1 M) and PhIP
was isolated by successive solid-phase extraction on a polystyrene-divinylbenzene column and on a silica-based mixed-mode
column with C 8 and-SO 3
− functional groups. Quantification was performed by gas chromatography-electron-impact ionization high-resolution mass spectrometry
in selected-ion-monitoring mode. The method was validated for determination of PhIP in the concentration range 0.5–25 ng g −1 hair with [ 2H 3]PhIP as internal standard. The limit of quantification was 0.26 ng g −1 hair. Within-day and between-day precision were in the ranges 1–27% and 2–15% relative standard deviation, respectively.
The hair sample used for method validation was found to contain 0.26 ng PhIP g −1 hair. 相似文献
2.
A simple stability-indicating reversed-phase liquid chromatographic method with diode-array detection was developed and validated
for the quantitative determination of ebastine in tablets and syrup. The LC method was carried out on a C 18 column with acetonitrile:phosphoric acid 0.1% pH 3.0 (55:45, v/ v) as mobile phase, at a flow rate of 1.2 mL min −1. Ultraviolet detection of ebastine was at 254 nm. A linear response ( r = 0.9999) was observed in the range of 10–80 μg mL −1. The RSD values for intra- and inter-day precision studies showed good results (RSD < 2%) and accuracy was greater than 98%.
Validation parameters such as specificity and robustness were also determined. The method was found to be stability-indicating
and can be applied to quantitative determination of ebastine in tablets and syrup. 相似文献
3.
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 C 18 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
4.
A sensitive and specific liquid chromatographic method with electrospray ionization mass spectrometry (LC–ESI-MS) has been
developed and validated for identification and quantification of mitiglinide in human urine. A simple liquid–liquid extraction
procedure was followed by separation on a C 18 column with gradient elution, and detection using a single-quadrupole mass spectrometer in selected-ion-monitoring (SIM)
mode. The method was tested using six different batches of urine. Linearity was established for the mitiglinide concentrations
in the range 0.005–1.0 μg mL −1, with a coefficient of determination ( r) of 0.9998 and good back-calculated accuracy and precision. Intra- and inter-day precision (as RSD, %) was below 10% and
accuracy for mitiglinide ranged from 85 to 115%. The lower limit of quantification was reproducible at 0.002 μg mL −1 for 500 μL urine. The proposed method enables unambiguous identification and quantification of mitiglinide in pre-clinical
and clinical studies. 相似文献
5.
A fast and sensitive liquid chromatography–mass spectrometry method was developed for the determination of ursolic acid (UA)
in rat plasma and tissues. Glycyrrhetinic acid was used as the internal standard (IS). Chromatographic separation was performed
on a 3.5 μm Zorbax SB-C18 column (30 mm × 2.1 mm) with a mobile phase consisting of methanol and aqueous 10 mM ammonium acetate
using gradient elution. Quantification was performed by selected ion monitoring with ( m/ z) − 455 for UA and ( m/ z) − 469 for the IS. The method was validated in the concentration range of 2.5 − 1470 ng mL −1 for plasma samples and 20 − 11760 ng g −1 for tissue homogenates. The intra- and inter-day assay of precision in plasma and tissues ranged from 1.6% to 7.1% and 3.7%
to 9.0%, respectively, and the intra- and inter-day assay accuracy was 84.2 − 106.9% and 82.1 − 108.1%, respectively. Recoveries
in plasma and tissues ranged from 83.2% to 106.2%. The limits of detections were 0.5 ng mL −1 or 4.0 ng g −1. The recoveries for all samples were >90%, except for liver, which indicated that ursolic acid may metabolize in liver. The
main pharmacokinetic parameters obtained were T
max = 0.42 ± 0.11 h, C
max = 1.10 ± 0.31 μg mL −1, AUC = 1.45 ± 0.21 μg h mL −1 and K
a = 5.64 ± 1.89 h −1. The concentrations of UA in rat lung, spleen, liver, heart, and cerebellum were studied for the first time. This method
is validated and could be applicable to the investigation of the pharmacokinetics and tissue distribution of UA in rats. 相似文献
6.
A liquid chromatographic–mass spectrometric (LC–MS) method has been developed and validated for simultaneous determination
of dehydroevodiamine and limonin from Evodia rutaecarpa in rat plasma. After addition of the internal standard, domperidone, plasma samples were extracted by liquid–liquid extraction
with ethyl acetate and separated on an Apollo C 18 column (250 mm × 4.6 mm, 5 μm), with methanol–0.01% formic acid water (60:40, v/ v) as mobile phase, within a runtime of 12.0 min. The analytes were detected without interference in the selected ion monitoring
(SIM) mode with positive electrospray ionization. The linear range was 1.0–500 ng mL −1 for dehydroevodiamine and 2.0–1,000 ng mL −1 for limonin, with lower limits of quantitation of 1.0 and 2.0 ng mL −1, respectively. Intra-day and inter-day precision were within 6.0% and 10.9%, respectively, for both analytes, and the accuracy
(relative error, RE, %) was less than 4.8% and 6.5%, respectively. The validated method was successfully applied to a comparative
pharmacokinetic study of dehydroevodiamine and limonin in rat plasma after oral administration of dehydroevodiamine, limonin,
and an aqueous extract of Evodiae fructus. The results indicated there were obvious differences between the pharmacokinetic behavior after oral administration of an
aqueous extract of Evodiae fructus compared with single substances. 相似文献
7.
An accurate, simple, reproducible, and sensitive liquid chromatographic method was developed and validated for the captopril determination in controlled release tablets. The analyses were performed at room temperature on a reversed-phase Phenomenex Luna C18 column (250 mm × 4.6 mm). The mobile phase was composed of water:methanol (45:55; v/v) pH 2.5, and it was eluted isocratically at a 1.0 mL min−1 flow rate. The method was validated in terms of specificity, linearity, quantification limit, detection limit, accuracy, precision and robustness. The response was linear in the range 0.3–1.5 mg mL−1 (r
2 = 0.9983). The relative standard deviation values for inter-and intra-day precision were 0.77% and 0.50%, respectively. Recoveries ranged between 97.7 and 99.1%. The method was successfully applied for the determination of captopril in the developed formulations. 相似文献
8.
In this study, a method for the determination of organic micro-pollutants, i.e. personal care products such as synthetic musk
fragrances, household bactericides, organophosphate flame retardants and plasticizers, as well as phthalates in sludge, has
been developed. This method is based on lyophilisation and accelerated solvent extraction followed by clean-up steps, i.e.
solid phase extraction and size exclusion chromatography. The determination is performed by gas chromatography coupled to
mass spectrometry. Stable isotope-labelled compounds such as musk xylene (MX D 15), tri- n-butylphosphate (T nBP D 27) and triphenylphosphate (TPP D 15) were used as internal standards. Recovery rates were determined to be 36–114% (with typical relative standard deviation
of 5% to 23%) for the target compounds. The limit of detection was 3–30 ng g −1, and the limit of quantification was 10–100 ng g −1 dry matter. 相似文献
9.
In the present study, a novel, fast and simple liquid chromatographic method was developed and validated for the simultaneous
determination of rosiglitazone and metformin in pharmaceutical preparations. The separation was achieved on a phenyl column
(250 × 4.6 mm i.d., 5 μm) using a mobile phase composed of acetonitrile:10.0 mM phosphate buffer pH 5.5 (70:30, v/ v). The flow rate was 1 mL min −1. UV detection was performed at 245 nm and verapamil was used as internal standard. The developed method was validated in
terms of stability, specificity, sensitivity, linearity, accuracy, precision and robustness. The limit of quantification was
0.02 μg mL −1 for both drugs. The method developed was successfully applied to the simultaneous determination of rosiglitazone and metformin
in pharmaceutical preparations. The results were compared to two methods reported in the literature and no significant difference
was found statistically. 相似文献
10.
In this study, a panel of haptens was synthesized for immunoconjugate preparation, and several haptens for heterologous tracer
conjugates were also prepared. A highly sensitive polyclonal antibody against the organophosphorus insecticide phosmet was
obtained and competitive direct enzyme-linked immunosorbent assays (cd-ELISA) for this pesticide were developed. In the cd-ELISA,
the limit of detection (IC 15) was 0.6 μg kg −1 and the sensitivity (IC 50) was 20 μg kg −1. The suitability of the ELISA for pesticide quantification in peach, apple, orange juice, and apple juice was also studied.
Good accuracy and precision were obtained with mean recoveries between 78% and 102.3% and mean coefficients of variation below
13.63%. Validation of the ELISA was conducted by high-performance liquid chromatography. The correlation between the data
obtained using the microwell assay and the high-performance liquid chromatography was good ( R
2 = 0.9849). The developed immunoassay methods were suitable for the rapid quantitative or qualitative determination of phosmet
in food samples. 相似文献
11.
A multisyringe flow injection analysis method for the determination of uranium in water samples was developed. The methodology
was based on the complexation reaction of uranium with arsenazo (III) at pH 2.0. Uranium concentrations were spectrophotometrically
detected at 649 nm using a light emitting diode. Under the optimized conditions, a linear dynamic range from 0.1 to 4.0 μg mL −1, a 3σ detection limit of 0.04 μg mL −1, and a 10σ quantification limit of 0.10 μg mL −1 were obtained. The reproducibility (%) at 0.5, 2.5, and 4.0 μg mL −1 was 2.5, 0.9, and 0.6%, respectively ( n = 10). The interference effect of some ions was tested. The proposed method was successfully applied to the determination
of uranium in water samples. 相似文献
12.
This paper describes the validation of an isocratic LC method for the assay of linezolid in tablets. Validation parameters
such as linearity, precision, accuracy, specificity, limit of detection, limit of quantitation and robustness were determined.
LC was carried out by reversed phase technique on an RP-18 column with a mobile phase composed of 1% acetic acid:methanol:acetonitrile
(50:25:25, v/v/v). Linezolid and your combination drug product were exposed to acid, base, oxidation, dry heat and photolytic stress conditions.
A linear response ( r > 0.9999) was observed in the range of 8.0–20.0 μg mL −1. The retention time of linezolid was 4.6 min. The method showed good recoveries and intra- and inter-day relative standard
deviations were less than 1.0%. The LOD and LOQ were 0.21 and 0.63 μg mL −1, respectively. The developed LC method for determination of related substances and assay determination of linezolid can be
used to evaluate the quality of regular production samples. It can also be used to test the stability samples of linezolid. 相似文献
13.
A new adsorbent is proposed for the solid-phase extraction of phenol and 1-naphthol from polluted water. The adsorbent (TX-SiO 2) is an organosilica composite made from a bifunctional immobilized layer comprising a major fraction (91%) of hydrophilic
diol groups and minor fraction (9%) of the amphiphilic long-chain nonionic surfactant Triton X-100 (polyoxyethylated isooctylphenol)
(TX). Under static conditions phenol was quantitatively extracted onto TX-SiO 2 in the form of a 4-nitrophenylazophenolate ion associate with cetyltrimethylammonium bromide. The capacity of TX-SiO 2 for phenol is 2.4 mg g −1 with distribution coefficients up to 3.4 × 10 4 mL g −1; corresponding data for 1-naphthol are 1.5 mg g −1 and 3 × 10 3 mL g −1. The distribution coefficient does not change significantly for solution volumes of 0.025–0.5 L and adsorbent mass less than
0.03 g; 1–90 μg analyte can be easily eluted by 1–3 mL acetonitrile with an overall recovery of 98.2% and 78.3% for phenol
and 1-naphthol, respectively. Linear correlation between acetonitrile solution absorbance ( A
540) and phenol concentration ( C) in water was found according to the equation A
540 = (6 ± 1) × 10 −2 + (0.9 ± 0.1) C (μmol L −1) with a detection range from 1 × 10 −8 mol L −1 (0.9 μL g −1) to 2 × 10 −7 mol L −1 (19 μL g −1), a limit of quantification of 1 μL g −1 (preconcentration factor 125), correlation coefficient of 0.936, and relative standard deviation of 2.5%. A solid-phase colorimetric
method was developed for quantitative determination of 1-naphthol on adsorbent phase using scanner technology and RGB numerical
analysis. The detection limit of 1-naphthol with this method is 6 μL g −1 while the quantification limit is 20 μL g −1. A test system was developed for naked eye monitoring of 1-naphthol impurities in water. The proposed test kit allows one
to observe changes in the adsorbent color when 1-naphthol concentration in water is 0.08–3.2 mL g −1. 相似文献
14.
Fleroxacin is a third generation fluoroquinolone with broad spectrum antibacterial activity. In this work an LC-DAD method
for the analysis of fleroxacin was developed and validated using UV detection at 286 nm. The method was validated for linearity,
precision, robustness, LOD, LOQ, specificity and accuracy at concentrations of 0.2–20.0 μg mL −1 and r
2 = 1. The LOD and LOQ were 0.059 and 0.197 μg, respectively, the recoveries were 99.92–102.0% and the CV was less than 2.0%.
The LC-DAD validated method provided analytical sensitivity, specificity and reproducibility suitable for quality control
analysis. 相似文献
15.
A sensitive and simple analytical method has been developed for determination of Sb(III), Sb(V), Se(IV), Se(VI), Te(IV), Te(VI),
and Bi(III) in garlic samples by using hydride-generation–atomic-fluorescence spectrometry (HG–AFS). The method is based on
a single extraction of the inorganic species by sonication at room temperature with 1 mol L −1 H 2SO 4 and washing of the solid phase with 0.1% ( w/ v) EDTA, followed by measurement of the corresponding hydrides generated under two different experimental conditions directly
and after a pre-reduction step. The limit of detection of the method was 0.7 ng g −1 for Sb(III), 1.0 ng g −1 for Sb(V), 1.3 ng g −1 for Se(IV), 1.0 ng g −1 for Se(VI), 1.1 ng g −1 for Te(IV), 0.5 ng g −1 for Te(VI), and 0.9 ng g −1 for Bi(III), in all cases expressed in terms of sample dry weight. 相似文献
16.
A sensitive and rapid liquid chromatographic method was successfully developed and validated for the determination of sibutramine
hydrochloride in bulk and capsules. Sibutramine in the presence of its degradation products was analyzed using UV detection
at 225 nm. Chromatography was performed on a reversed-phase C 8 (150 × 4.0 mm I.D., 5 μm) analytical column under isocratic conditions. The mobile phase was composed of acetonitrile:water
(aqueous phase containing 0.3% triethylamine and pH adjusted to 7.0) (75:25, v/ v) at a flow-rate of 1.1 mL min −1. No chromatographic interference was found during the analysis. Light was the stress condition which most contributed to
sibutramine degradation. The method showed a linear response ( r > 0.999) from 30 to 90 μg mL −1. The mean recovery for capsules was 101.2%. Inter-day assays showed relative standard deviations of 0.42 and 1.62% for bulk
and capsules, respectively. The developed method is able to separate sibutramine from its major degradation products and it
may be used in the quality control of this active pharmaceutical ingredient in both bulk and capsules. 相似文献
17.
A new, simple, rapid and specific reversed-phase high-performance liquid chromatography (HPLC) method was developed and validated for the determination of fluvoxamine in pharmaceutical dosage forms. The HPLC separation was achieved on a C 18 μ-Bondapack column (250 mm × 4.6 mm) using a mobile phase of acetonitrile–water (80:20, v/v) at a flow rate of 1 mL min −1. Proposed method is based on the derivatization of fluvoxamine with 1,2-naphthoquinone-4-sulphonic acid sodium salt (NQS) in borate buffer of pH 8.5 to yield a orange product. The HPLC method is based on measurement of the derivatized product using UV-visible absorbance detection at 450 nm. The method was validated for specificity, linearity, precision, accuracy, robustness. The degree of linearity of the calibration curves, the percent recoveries of fluvoxamine, the limit of detection and quantification, for the HPLC method were determined. The assay was linear over the concentration range of 45–145 ng mL −1 ( r = 0.9999). Limit of detection and quantification for fluvoxamine were 15 and 50 ng mL −1, respectively. The results of the developed procedure (proposed method) for fluvoxamine content in tablets were compared with those by the official method. The method was found to be simple, specific, precise, accurate, reproducible and robust. 相似文献
18.
It is observed that Ag(I) catalyzes the rate of substitution of phenylhydrazine (PhNHNH 2) into hexacyanoferrate(II), producing a cherry red colored complex, [Fe(CN) 5PhNHNH 2] 3−. The reaction was monitored at 488 nm leading to the formation of the complex under the conditions: [Fe(CN) 6] 4− (5.0 × 10 −3 mol dm −3), PhNHNH 2 (2.0 × 10 −3 mol dm −3), temperature (25 ± 0.1 °C), pH (2.8 ± 0.02), and ionic strength, I (0.02 mol dm −3), (KNO 3). Under optimum conditions, absorbance at fixed times ( A
t
) is linearly related to Ag(I) in the concentration range 10.79–97.08 ng cm −3, in the presence of several diverse ions. The highest percentage error and relative standard deviations in the entire range
of Ag(I) determination are found to be 2.5% and 0.16, with a detection limit of 8.75 ng cm −3 of silver(I). The experimental accuracies expressed in terms of percentage recoveries are in the range of 97.87–102.50. The
method was successfully applied for the determination of Ag(I) in a few synthetic samples and found to be in good agreement
with those obtained from atomic absorption spectrophotometry (AAS). The validity of the proposed method has also been tested
for Ag(I) determination in spiked drinking water samples. The present catalytic kinetic method (CKM) is highly sensitive,
selective, reproducible, and inexpensive. A review of recently published catalytic spectrophotometric methods for determination
of Ag(I) has also been presented for comparison. 相似文献
19.
A high-performance liquid chromatographic method with evaporative light-scattering detection (ELSD) has been developed for
analysis of spectinomycin and related impurities. Separation of spectinomycin from structurally related impurities was achieved
on a C 18 column. The optimized mobile phase was 25 mmol L −1 ammonium acetate (pH 7.5)-methanol, 90:10 ( v/ v), at a flow rate of 0.6 mL min −1. The temperature of the drift tube of the ELSD was 95°C and the flow rate of carrier gas was 2.2 L min −1. The accuracy, specificity, precision, linearity, sensitivity, and robustness of the method were validated in accordance
with ICH guidelines. In addition to determination of spectinomycin and related impurities, the method is also ideal for determination
of the salts spectinomycin hydrochloride and spectinomycin sulfate. 相似文献
20.
A capillary zone electrophoresis procedure has been developed for the chiral determination of pheniramine in eye drop. Native
and derivative cyclodextrins ( CDs) including γ-CD, β-CD, hydroxypropyl-β-CD and dimethyl-β-CD were tested as chiral selectors. Using 30 mM hydroxypropyl-β-CD
in 50 mM phosphate buffer (pH 3.0), the acceptable resolution value ( R = 1.55) was obtained. The assay was validated for linearity (3.3 × 10 −6–5.0 × 10 −4 M; R
2 = 0.9996), limit of detection (3.3 × 10 −6 M), limit of quantification (8.5 × 10 −6 M), analytical precision by terms of intra- and inter-day variability (RSD ≤ 2.57%), and accuracy (recovery ≥ 89.3%). The
content of pheniramine in eye drop obtained by the proposed method was in good agreement with the declared value. The results
indicated that pheniramine in the eye drop was present as the racemate. 相似文献
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