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1.
Combined use of carbon nanotubes and ionic liquid to improve the determination of antidepressants in urine samples by liquid chromatography 总被引:1,自引:0,他引:1
Cruz-Vera M Lucena R Cárdenas S Valcárcel M 《Analytical and bioanalytical chemistry》2008,391(4):1139-1145
Antidepressants are widely used for the treatment of psychiatric disorders and therefore their monitoring in biological fluids
is quite important taking into account that they can produce dangerous biochemical imbalances in toxic doses. A method for
the determination of antidepressants in urine samples is presented using solid-phase extraction (SPE) and high-performance
liquid chromatography (HPLC) with ultraviolet (UV) detection. Home-made cartridges containing 30 mg multiwall carbon nanotubes
are employed for isolation of the analytes from the sample, allowing also the preconcentration of the analytes prior to the
HPLC analysis. Chromatographic separation was achieved in a reversed-phase C8 column using the ionic liquid 1-butyl-3-methylimidazolium trifluoromethanesulfonate as silanol activity suppressor, which
enhances peak symmetry and chromatographic resolution. Limits of detection were 12.3 ng mL−1 for trazodone and 90.1 ng mL−1 for fluoxetine. The repeatability of the proposed method expressed as RSD (n = 11) varied between 3.4% (fluoxetine) and 5.0% (desipramine and mianserine). Thus, the method is suitable for the therapeutic
monitoring of antidepressants in urine samples. 相似文献
2.
This paper describes the novel preparation of three kinds of nanofibers [poly(styrene-co-methacrylic acid), poly(styrene-co-p-styrene sulfonate), polystyrene] investigated as solid-phase extraction (SPE) sorbents to extract six compounds (nitrobenzene,
2-naphthol, benzene, n-butyl p-hydroxybenzoate, naphthalene, p-dichlorobenzene) in environmental water by high-performance liquid chromatography. Parameters affecting extraction efficiency
were investigated in detail to explore the extraction mechanism of the nanofibers. Under optimized conditions, six compounds
followed an excellent linear relationship in the range 10–5,000 ng mL−1 with coefficients of determination (r
2) greater than 0.99. The repeatability (expressed as relative standard deviations) was from 3.0 to 7.0%, corresponding to
2.0 mL of water samples at 25 and 500 ng mL−1 spiked levels for the six compounds. The limits of detection varied from 0.01 to 0.15 ng mL−1 (signal-to-noise ratio of3). A comparison of the SPE using nanofibers as sorbents and the most commonly used octadecylsilica
SPE cartridges was carried out in terms of absolute recovery, sensitivity, and reproducibility for the compounds investigated.
Finally, the method was applied to four real water samples. The results highlighted the importance of functional groups, and
the polarity of nanofibers in controlling sorption of target compounds, and clearly showed that the new method could be a
viable and environmentally friendly technique for analyzing pollutants in environmental samples. 相似文献
3.
Li C Wen D Zhang J Chen Z Cong W Rao Z Liu H 《Analytical and bioanalytical chemistry》2006,386(7-8):1985-1993
Metabolism of four tobacco-specific N-nitrosamines (TSNAs), N′-nitrosonornicotine (NNN), N′-nitrosoanatabine (NAT), N′-nitrosoanabasine (NAB), and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) has been studied by solid-phase extraction
(SPE) and liquid chromatography–tandem mass spectrometry (LC–MS–MS). 4-(Methylnitrosamino)-4-(3-pyridyl)-1-butanol (iso-NNAL)
was used as internal standard. SPE and LC–MS–MS was found to be a rapid, simple, sensitive, and selective method for analysis
of TSNAs in rabbit serum. The relative standard deviation (R.S.D., n = 6) for analysis of 5 ng mL−1 and 0.5 ng mL−1 standards and of serum sample spiked with 5 ng mL−1 standards of five TSNAs was 2.1–11% and recovery of 5 ng mL−1 standards from serum was 100.2–112.9%. A good linear relationship was obtained between peak area ratio and concentration
in the range of 0.2–100 ng mL−1 for NNAL and 0.5–100 ng mL−1 for other four TSNAs, with correlation coefficients (R
2) >0.99 (both linear and log–log regression). Detection limits for standards in solvent were between 0.04 and 0.10 ng mL−1. Doses of TSNAs administered to rabbits via the auricular vein were 4.67 μg kg−1 and 11.67 μg kg−1, in accordance with the different levels in cigarettes. Metabolic curves were obtained for the four TSNAs and for 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol
(NNAL), a metabolite of NNK; on the basis of these curves we modeled metabolic kinetic equations for these TSNAs by nonlinear
curve fitting. 相似文献
4.
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
5.
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
6.
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
7.
Lingli Zhang Yi Chen Mei Lin Guorong Fan Weiquan Zhao Yutian Wu 《Chromatographia》2007,65(5-6):305-311
The quick separation and simultaneous determination of d-amphetamine and diphenhydramine in the quick-acting anti-motion capsules was investigated by capillary zone electrophoresis.
The influence of different parameters (internal standard, injection modes, pH, concentration of the running buffer and applied
voltage) was systematically studied. The two compounds could be well separated within 2.0 min in a 40.2 cm fused-silica capillary
at a separation voltage of 20 kV in a 50 mM phosphate–12.5 mM borate buffer adjusted to pH 5.5. Correlation coefficients for
calibration curves in the range 0.50–1.50 μg mL−1 for d-amphetamine and 2.75–8.25 μg mL−1 for diphenhydramine were higher than 0.999. The limits of detection of d-amphetamine and diphenhydramine were 10.0 and 5.5 ng mL−1 and the recoveries of the compounds in the QAAMC were 99.80 and 99.85%, respectively.
The authors L. Zhang and Y. Chen equally contributed to this work. 相似文献
8.
Determination of triazine herbicides in human body fluids by solid-phase microextraction and capillary gas chromatography 总被引:2,自引:0,他引:2
T. Kumazawa X. -P. Lee K. Kondo K. Sato H. Seno K. Watanabe-Suzuki A. Ishii O. Suzuki 《Chromatographia》2000,52(3-4):195-199
Summary Eight triazine herbicides, prometon, propazine, atrazine, simazine, prometryn, ametryn, metribuzin, and cyanazine, have been
extracted from human whole blood and urine samples by headspace solid-phase microextraction (SPME) with a polydimethylsiloxane-coated
fiber and quantified by capillary gas chromatography with nitrogen-phosphorus detection.
Extraction efficiencies for all compounds were 0.21–0.99% for whole blood, except for cyanazine (0.06%). For urine, the extraction
efficiencies for prometon, propazine, atrazine, prometryn and ametryn were 13.6–38.1%, and those of simazine, metribuzin and
cyanazine were 1.35–8.73%.
The regression equations for the compounds extracted from whole blood were linear within the concentration ranged 0.01–1 μg
(0.5 mL)−1 for prometon, propazine, atrazine, prometryn, and ametryn, and 0.02–1 μg (0.5 mL)−1 for simazine, metribuzin, and cyanazine. For urine, regression equations for all compounds were linear within the concentration
range 0.005–0.25 μg mL−1. Compound detection limits were 2.8–9.0 ng (0.5 mL)−1 and 0.4–2.0 ng mL−1 for whole blood and urine, respectively. The coefficients of within-day and day-to-day variation were satisfactory for all
the compounds, and not greater than 10.3 and 14.2%, respectively.
Data obtained from determination of atrazine in rat whole blood after oral administration of the compound are also presented. 相似文献
9.
Solid-phase microextraction coupled with microcolumn liquid chromatography for the analysis of amitriptyline in human urine 总被引:1,自引:0,他引:1
Summary Solid-phase microextraction (SPME) is a solvent-free sample-preparation technique that enables isolation and pre-concentration
of analytes from a sample on a thin film coating a fused-silica fiber. In this study SPME coupled with microcolumn liquid
chromatography (micro LC) has been used for the determination of four tricyclic antidepressants (amitriptyline, imipramine,
nortriptyline, and desipramine) in human urine. SPME conditions which affect extraction efficiency were optimized, and under
the optimum conditions the system was a few hundred times more sensitive than direct LC analysis without SPME. For amitriptyline
the detection limit was 3 ng mL−1 and the calibration curve was linear in the range of 5–500 ng mL−1. The SPME-micro LC method has been applied to the analysis of amitriptyline in patient’s urine. 相似文献
10.
Summary A method was developed for the separation and quantification of the warfare nerve agent sarin (O-isopropylmethylphosphonoflouridate), its metabolite methylphosphonic acid, the anti nerve agent drug pyridostigmine bromide
(PB;3-dimethylaminocarbonyloxy-N-methyl pyridinium bromide) and its metaboliteN-methyl-3-hydroxypyridinium bromide in rat plasma and urine. The method involved using solid phase extraction and high performance
liquid chromatography (HPLC) with reversed phase C18 column, and UV detection at 280 nm. The compounds were separated using gradient of 1% to 55% acetonitrile in 0.1% triflouroacetic
acid water solution (pH 3.20) at flow rate of 0.9 ml/min in a period of 15 min. The retention times ranged from 4.4–12.1 min.
The limits of detection were 50 ng mL−1 for PB andN-methyl-3-hydroxypyridinium bromide, and 10 μg mL−1 for sarin and methylphosphonic acid, while limits of quantitation were between 100 ng mL−1–12 μg mL−1. Average percentage recovery of five spiked samples from plasma were 84.6±8.4, 86.5±9.0, 76.4±8.5, 81.3±8.2, and from urine
78.5±7.9, 76.4±7.8, 74.4±8.4, 80.6±6.8 for sarin, methylphosphonic acid, pyridostigmine bromide andN-methyl-3-hydroxypyridinium bromide, respectively. This method was applied to analyze the above chemicals and metabolites
following combined administration in rats. 相似文献
11.
Summary A method for determination of trace amounts of the pesticides tebufenpyrad and oxadiazon, previous solid-phase microextraction
(SPME), was developed using gas chromatographymass spectrometry and selected ion monitoring (GC-MS; SIM). Both pesticides
were extracted with a fused silica fiber coated with 100 μm polydimethylsiloxane. The effects of pH ionic strength, sample
volume, extraction and desorption times as well as extraction temperature were studied. The linear concentration range of
application was 0.5–250 ng mL−1 for both compounds, with a detection limit of 0.06 ng mL−1 for tebufenpyrad and 0.02 ng mL−1 for oxadiazon. SPME-GC-MS analysis yielded good reproducibility (RSD between 7.5–10.1%). It was used to check the eventual
existence of tebufenpyrad and oxadiazon above this limit in water and soil samples from Granada (Spain) as well as in human
urine samples. The method validation was completed with spiked matrix samples. It can be applied as a monitoring tool for
water, soil and urine in the investigation of environmental and occupational exposure to tebufenpyrad and oxadiazon. 相似文献
12.
Piotr Kowalski Marcin Marszałł Ilona Olędzka Wojciech Czarnowski 《Chromatographia》2007,66(5-6):357-361
Two rapid and popular methods—capillary electrophoresis (CE) and high-performance liquid chromatography (HPLC) have been compared
for analysis of cotinine in human urine. Cotinine was analyzed in less than 7 min, with detection limits of 5 and 3.2 ng mL−1 for CE and HPLC, respectively. The performance of the methods was evaluated in terms of sensitivity, specificity, precision,
accuracy, and limits of detection and quantification. Calibration plots were linear in the range 50–4,000 ng mL−1, at least, and mean recoveries were satisfactory for both techniques. The methods were successfully used for quantification
of cotinine in urine. 相似文献
13.
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
14.
Haiyang Jiang Shuangyang Ding Fei Xu Sijun Zhao Jihong He Jinfeng Liu Xiaolin Hou Jianzhong Shen 《Chromatographia》2007,66(5-6):411-414
Eprinomectin is a novel and potent antiparasitic animal health drug. An analytical procedure for the determination of EPR
in bovine urine and feces has been developed. The urine sample was centrifuged and alkalized with ammonia following solid
phase extraction. The fecal sample was extracted with acetonitrile, defatted with hexane, cleaned-up using C18 cartridge.
All samples were analyzed by high performance liquid chromatography with fluorescence detection after derivatization with
N-methylimidazole. The limits of detection are 0.5 ng mL−1 and 0.5 ng g−1, respectively. Fortified at 2, 10, 50, and 100 ng mL−1(ng g−1), inter-assay recoveries of EPR in cattle urine and feces were in the range of 87.9–91.5% and 78.6–86.3%, with coefficients
of variation of 5.4–10.2% and 1.4–7.2%, respectively. Intra-assay mean recoveries of the analytes were 82.2–86.5% and 79.6–87.3%,
with coefficients of variation of 7.8–11.5% and 6.3–7.8%, respectively. The method was used to study the excretion of eprinomectin
in bovine urine and feces after subcutaneous administration at a dose of 0.5 mg kg−1. 相似文献
15.
Summary A reliable and sensitive high-performance liquid chromatographic method for the determination of the recent antidepressant
citalopram and two metabolites in human plasma has been developed. Fluorescence detection at 300 nm was used, exciting at
238 nm. Separation was obtained using a reversed-phase column (C18, 250 × 3.0 mm i.d., 5 μm) and a mobile phase. 40% acetonitrile:
60% aqueous tetramethylammonium perchlorate (pH 1.9). Calibration curves were linear over a working range: 5–300 ng mL−1 for citalopram, 2.5–150.0 ng mL−1 for desmethylcitalopram and 2.5–50.0 ng mL−1 for didesmethylcitalopram. The limits of quantitation (LOQ) were 1.5 ng mL−1 for citalopram and desmethylcitalopram and 2.0 ng mL−1 for didesmethylcitalopram. Precision data, as well as accuracy, were satisfactory and no interference from different psychotropic
drugs was found. The method was therefore suitable for therapeutic drug monitoring of citalopram and its active metabolites
in plasma of depressed patients. 相似文献
16.
M. A. Raggi F. Bugamelli C. Sabbioni D. De Ronchi S. Pinzauti V. Volterra 《Chromatographia》2000,51(3-4):147-153
Summary An HPLC method with electrochemical detection has been developed for the determination of clozapine and its main metabolites,
desmethylclozapine and clozapine N-oxide, in human plasma. An accurate pretreatment of the biological samples was implemented
by means of solid phase extraction (SPE) on HLB cartridges. This improved pretreatment, together with a new mobile phase,
allows for the accurate determination of clozapine N-oxide, which could not be quantitated by a previous method. The method
uses only 100 μL of plasma for one complete analysis and shows good recovery values for all three analytes. The eluates from
the SPE procedure were chromatographed in a reversed phase C18 column using a mobile phase composed of phosphate buffer, acetonitrile
and methanol. Clozapine, desmethylclozapine and clozapine N-oxide were eluted in less than 10 minutes, without any interference
from the biological matrix. Linearity was observed over the 2.50–150 ng mL−1 (clozapine and desmethylclozapine) or 1.25–75 ng mL−1 clozapine N-oxide) range for the three analytes, with satisfactory repeatability values. The limit of detection was 0.3 ng
mL−1 for clozapine and desmethylclozapine, samples of patients treated with Leponex gave good results. No interference from other
common central nervous system drugs was found. This method seems to be a useful tool for pharmacokinetic studies and for clinical
monitoring, because of its need for small plasma samples and its high sensitivity and selectivity. 相似文献
17.
Benito-Peña E Martins S Orellana G Moreno-Bondi MC 《Analytical and bioanalytical chemistry》2009,393(1):235-245
A novel water-compatible molecularly imprinted polymer (MIP), prepared with enrofloxacin (ENR) as the template, has been optimised
for the selective extraction of fluoroquinolone antibiotics in aqueous media. The results of a morphological characterisation
and selectivity tests of the polymer material for ENR and related derivatives are reported. High affinity for the piperazine-based
fluoroquinolones marbofloxacin, ciprofloxacin, norfloxacin and ofloxacin was observed, whereas no retention was found for
nonrelated antibiotics. Various parameters affecting the extraction efficiency of the polymer have been optimised to achieve
selective extraction of the antibiotics from real samples and to reduce nonspecific interactions. These findings resulted
in a MISPE/HPLC-FLD method allowing direct extraction of the analytes from aqueous samples with a selective wash using just
50% (v/v) organic solvent. The method showed excellent recoveries and precision when buffered urine samples fortified at five
concentration levels (25–250 ng mL−1 each) of marbofloxacin, ciprofloxacin, norfloxacin, enrofloxacin and sarafloxacin were tested (53–88%, RSD 1–10%, n = 3). Moreover, the biological matrix of the aqueous samples did not influence the preconcentration efficiency of the fluoroquinolones
on the MIP cartridges; no significant differences were observed between the recovery rates of the antibiotics in buffer and
urine samples. The detection limits of the whole process range between 1.9 and 34 ng mL–1 when 5-mL urine samples are processed. The developed method has been successfully applied to preconcentration of norfloxacin
in urine samples of a medicated patient, demonstrating the ability of the novel MIP for selective extraction of fluoroquinolones
in urine samples. 相似文献
18.
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
19.
The work presented in this paper deals with the combination of capillary electrophoresis (CE) with electrospray mass spectrometry (MS) for the determination of drug residues in water. CE/MS methods have been developed based on either aqueous or non-aqueous ammonium acetate solutions as the carrier electrolyte for the separation of selected drugs. The different separation conditions were compared in terms of selectivity and detection limits; both aqueous and non-aqueous CE proved to be suitable for the present analytical task, exhibiting detection limits between 3 and 93 μg/dm3 (injected standard concentration) corresponding to concentrations between 5 and 19 ng/dm3 in the sample. A combination of liquid-liquid extraction and solid-phase extraction was investigated for sample pretreatment, yielding enrichment factors of 10000. The applicability of CE/MS was demonstrated for the analysis of several river water samples. 相似文献
20.
Separation and simultaneous determination of quinolone antibiotics by capillary zone electrophoresis
Summary The potential of capillary zone electrophoresis has been investigated for the separation and quantitative determination of
some quinolone antibiotics. The influence of different conditions, such as the nature and concentration of the electrophoretic
electrolyte, on migration time, peak symmetry, efficiency and resolution was studied. A buffer consisting of 100mm HEPES adjusted to pH 8.5 containing 10% (v/v) acetonitrile was found to furnish a very efficient and stable electrophoretic system for the separation of exoxacin, ciprofloxacin,
ofloxacin, oxolinic acid, nalidixic acid and pipemedic acid. A linear relationship between concentration and peak area for
each compound was obtained in the concentration range 0.25–40 μg mL−1; detection limits were approximately 0.25 ng mL−1. It was demonstrated that the method can be used for the simultaneous determination of these six antibiotics in serum and
urine samples. 相似文献