共查询到20条相似文献,搜索用时 31 毫秒
1.
Macwan JS Ionita IA Dostalek M Akhlaghi F 《Analytical and bioanalytical chemistry》2011,400(2):423-433
The aim of the proposed work was to develop and validate a simple and sensitive assay for the analysis of atorvastatin (ATV)
acid, ortho- and para-hydroxy-ATV, ATV lactone, and ortho- and para-hydroxy-ATV lactone in human plasma using liquid chromatography-tandem mass spectrometry. All six analytes and corresponding
deuterium (d5)-labeled internal standards were extracted from 50 μL of human plasma by protein precipitation. The chromatographic
separation of analytes was achieved using a Zorbax-SB Phenyl column (2.1 mm × 100 mm, 3.5 μm). The mobile phase consisted
of a gradient mixture of 0.1% v/v glacial acetic acid in 10% v/v methanol in water (solvent A) and 40% v/v methanol in acetonitrile (solvent B). All analytes including ortho- and para-hydroxy metabolites were baseline-separated within 7.0 min using a flow rate of 0.35 mL/min. Mass spectrometry detection was
carried out in positive electrospray ionization mode, with multiple-reaction monitoring scan. The calibration curves for all
analytes were linear (R
2 ≥ 0.9975, n = 3) over the concentration range of 0.05–100 ng/mL and with lower limit of quantitation of 0.05 ng/mL. Mean extraction recoveries
ranged between 88.6–111%. Intra- and inter-run mean percent accuracy were between 85–115% and percent imprecision was ≤ 15%.
Stability studies revealed that ATV acid and lactone forms were stable in plasma during bench top (6 h on ice-water slurry),
at the end of three successive freeze and thaw cycles and at −80 °C for 3 months. The method was successfully applied in a
clinical study to determine concentrations of ATV and its metabolites over 12 h post-dose in patients receiving atorvastatin. 相似文献
2.
A simple and sensitive assay was developed and validated for the simultaneous quantification of rosuvastatin acid (RST), rosuvastatin-5S-lactone (RST-LAC), and N-desmethyl rosuvastatin (DM-RST), in buffered human plasma using liquid chromatography–tandem mass spectrometry (LC-MS/MS).
All the three analytes and the corresponding deuterium-labeled (d6) internal standards were extracted from 50 μL of buffered
human plasma by protein precipitation. The analytes were chromatographically separated using a Zorbax-SB Phenyl column (2.1 mm × 100 mm,
3.5 μm). The mobile phase comprised of a gradient mixture of 0.1% v/v glacial acetic acid in 10% v/v methanol in water (solvent A) and 40% v/v methanol in acetonitrile (solvent B). The analytes were separated at baseline within 6.0 min using a flow rate of 0.35 mL/min.
Mass spectrometry detection was carried out in positive electrospray ionization mode. The calibration curves for all three
analytes were linear (R ≥ 0.9964, n = 3) over the concentration range of 0.1–100 ng/mL for RST and RST-LAC, and 0.5–100 ng/mL for DM-RST. Mean extraction recoveries
ranged within 88.0–106%. Intra- and inter-run mean percent accuracy were within 91.8–111% and percent imprecision was ≤15%.
Stability studies revealed that all the analytes were stable in matrix during bench-top (6 h on ice–water slurry), at the
end of three successive freeze and thaw cycles and at −80°C for 1 month. The method was successfully applied in a clinical
study to determine the concentrations of RST and the lactone metabolite over 12-h post-dose in patients who received a single
dose of rosuvastatin. 相似文献
3.
Authors developed a simple, sensitive, selective, rapid, rugged, and reproducible liquid chromatography–tandem mass spectrometry
method for the quantification of eletriptan (EP) in human plasma using naratriptan (NP) as an internal standard (IS). Chromatographic
separation was performed on Ascentis Express C18, 50 × 4.6 mm, 2.7 μm column. Mobile phase was composed of 0.1% formic acid:
methanol (40:60 v/v), with 0.5 mL/min flow rate. Drug and IS were extracted by liquid–liquid extraction. EP and NP were detected with proton
adducts at m/z 383.2→84.3 and 336.2→97.8 in multiple reaction monitoring (MRM) positive mode, respectively. The method was validated with
the correlation coefficients of (r
2) ≥ 0.9963 over a linear concentration range of 0.5–250.0 ng/mL. This method demonstrated intra- and inter-day precision within
1.4–9.2% and 4.4–5.5% and accuracy within 96.8–103% and 98.5–99.8% for EP. This method is successfully applied in the bioequivalence
study of 24 human volunteers. 相似文献
4.
Carola W. N. Damen Hilde Rosing Jan H. M. Schellens Jos H. Beijnen 《Analytical and bioanalytical chemistry》2009,394(4):1171-1182
A sensitive, specific and efficient high-performance liquid chromatography-tandem mass spectrometry assay for the simultaneous
determination of vincristine and actinomycin-D in human dried blood spots is presented. Dried blood spots were punched out
of a collection paper with a 0.25-in.-diameter punch. The analytes were extracted from the punched-out disc using sonication
during 15 min in a mixture of acetonitrile–methanol–water (1:1:1, v/v/v) containing the internal standard vinorelbine. Twenty-microlitre volumes were injected onto the HPLC system. Separation was
achieved on a 50 × 2.1 mm ID Xbridge C18 column using elution with 1 mM ammonium acetate–acetonitrile (70:30, v/v) adjusted to pH 10.5 with ammonia and run in a gradient with methanol at a flow rate of 0.4 mL/min. HPLC run time was 6 min.
The assay quantifies vincristine from 1 to 100 ng/mL and actinomycine-D from 2 to 250 ng/mL using a blood sample obtained
by a simple finger prick. Validation results demonstrate that vincristine and actinomycin-D can be accurately and precisely
quantified in human dried blood spots with the presented method. The assay can now be used to support clinical pharmacologic
studies with vincristine and actinomycin-D. 相似文献
5.
Carpinteiro I Abuin B Ramil M Rodríguez I Cela R 《Analytical and bioanalytical chemistry》2012,402(7):2471-2478
An improved selectivity method for the simultaneous determination of four benzotriazoles (benzotriazole, 4-methylbenzotriazole,
5-methylbenzotriazole, and 5,6-dimethyl-1H-benzotriazole) and six benzothiazoles (benzothiazole, 2-hydroxybenzothiazole, 2-benzothiazolamine, mercaptobenzothiazole,
2-methylbenzothiazole, and 2-methylthiobenzothiazole) in aqueous matrices has been developed. Under optimal conditions, analytes
are concentrated using a MAX solid-phase extraction (SPE) cartridge, based on divinylbenzene-N-vinylpyrrolidone functionalized with quaternary amine groups, which allows reversed-phase interactions in combination with
ionic exchange. Selected compounds are recovered with methanol–acetone 7:3 (v/v) whereas acidic interferences remained attached to the sorbent, and as determined by liquid chromatography coupled to tandem
mass spectrometry (LC-MS/MS), LOQs for surface, urban and industrial wastewater are in the range of 0.002–0.29 ng/mL. Figures
of merit of the method revealed good precision (RSD% <12%), linearity (R
2 > 0.99) and accuracy (%R = 80–100%) for surface waters and effluents allowing direct external standard quantification. For more complex samples, such
as urban and industrial raw wastewater, either the standard addition method or pseudo-external standard calibration using
matrix matched standards are recommended. Analysis of different real samples, surface, urban wastewater and, for the first
time, metal industry wastewater, reflected concentrations up to 310 ng/mL. The methylbenzotriazole isomers ratio was also
determined. 相似文献
6.
Hua Wei Jun Wen Rui Xie Houwen Lin Guorong Fan Yutian Wu 《Analytical and bioanalytical chemistry》2009,395(5):1461-1469
A sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method, followed by a 96-well protein precipitation,
has been developed and fully validated for the determination of Phakellistatin 13 (PK13), a new cyclic heptapeptide isolated
from the sponge Phakellia fusca Thiele, in rat plasma. After protein precipitation of the plasma samples (50 μL) in a 96-well plate by methanol (200 μL)
containing the internal standard Pseudostellarin B (20 ng/mL), the plate was vortex mixed for 3 min. Following filtration
for 5 min, the filtrate was directly injected into the LC-MS/MS system. The analytes were separated on an XB-C18 analytical
column (5 μm, 50 mm × 4.6 mm i.d.) using an eluent of methanol–water (85:15, v/v) and detected by electrospray ionization mass spectrometry in the negative multiple reaction monitoring mode with a chromatographic
run time of 5.0 min. The method was sensitive with a lower limit of quantification (LLOQ) of 0.1 ng/mL, with good linearity
(r > 0.999) over the quantitation range of 0.1–5 ng/mL. The validation results demonstrated that this method was significantly
specific, accurate, precise, and was successfully applied in measuring levels of PK13 in rat plasma following intravenous
administration of 20, 50, and 100 μg/kg of peptide in rats, respectively, which was suitable for the preclinical pharmacokinetic
studies on PK13. 相似文献
7.
Vitor RV Martins MC Figueiredo EC Martins I 《Analytical and bioanalytical chemistry》2011,400(7):2109-2117
A method constituted by molecularly imprinted solid-phase extraction (MISPE) with high-performance liquid chromatography coupled
to diode array detector (HPLC-DAD) was developed for cotinine analysis in saliva samples. For this purpose, the separation
was carried out with a C18 reversed-phase column at 20 °C. The mobile phase which was composed of a mixture of 09:91 (v/v) acetonitrile/phosphate buffer, pH 6.3, was delivered with isocratic flow rate at 1.4 mL min−1. Employing MISPE, the best conditions were achieved with 1.5 mL of saliva plus 1.5 mL of 0.1 mol L−1 of acetate buffer, pH 5.5, which were then passed through a cartridge previously conditioned with 2 mL acetonitrile, 2 mL
methanol, and 2 mL of 0.1 mol L−1 sodium acetate buffer, pH 5.5. The washing was carried out with 1 mL deionized water, 1 mL of 0.1 mol L−1 sodium hydroxide, and 1 mL hexane; finally; the cotinine elution was carried out with 3 mL methanol/water (97.5: 2.5, v/v). Linearity ranged from 30 to 500 ng mL−1 with r > 0.99. Intra-assay, interassay precision, and accuracy ranged from 3.1% to 10.1%, 5.2% to 15.9%, and 99.22% to 111.17%,
respectively. The detection and quantification limits were 10 and 30 ng mL−1, respectively. This investigation has provided a reliable method for routine cotinine determination in saliva, and it is
an important tool for monitoring cigarette smoke exposure in smokers. The method was applied in five smokers’ samples who
consumed around five to 20 cigarettes per day and the values of cotinine in saliva were from 66.7 to 316.16 ng mL−1. 相似文献
8.
Zhao J Han X Zhao X Wang C Li Q Chen X Bi K 《Analytical and bioanalytical chemistry》2011,401(1):289-296
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 C18 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
9.
Reiter EV Cichna-Markl M Chung DH Shim WB Zentek J Razzazi-Fazeli E 《Analytical and bioanalytical chemistry》2011,400(8):2615-2622
The paper presents a new sample clean-up method based on immuno-ultrafiltration for the analysis of ochratoxin A in cereals.
In contrast to immunoaffinity chromatography, in immuno-ultrafiltration, the antibodies are used in non-immobilised form.
Ochratoxin A was extracted with ACN/water (60/40, v/v), and the extract was loaded onto the ultrafiltration device. After a washing step with phosphate-buffered saline, containing
0.05% Tween 20, ochratoxin A was eluted with MeOH/acetic acid (99/1, v/v). The detection of ochratoxin A was carried out with high-performance liquid chromatography and a fluorescence detector coupled
to an electrochemical cell (Coring cell). The electrochemical cell was used to eliminate matrix interferences by oxidising
matrix compounds. The method was validated by repeatedly analysing spiked barley and rye samples as well as a certified wheat
reference material. Recoveries and standard deviations (1 SD) were found to be 71 ± 9%, 77 ± 12% and 77 ± 8% in wheat, barley
and rye, respectively. The limit of detection (S/N = 3) and limit of quantitation (S/N = 10) were determined to be 0.4 μg kg-1 and 1 μg kg-1. The analysis of the certified reference material resulted in ochratoxin A concentrations which were in the range assigned
by the producer. Additionally, the effect of the electrochemical cell on other widely used clean-up techniques, namely the
immunoaffinity clean-up and multifunctional columns (Mycosep #229), was evaluated. In all clean-up methods, an improvement
of the chromatogram quality was registered. 相似文献
10.
N. Negreira I. Rodríguez E. Rubí R. Cela 《Analytical and bioanalytical chemistry》2010,398(2):995-1004
The performance of the dispersive liquid–liquid microextraction (DLLME) technique for the determination of eight UV filters
and a structurally related personal care species, benzyl salicylate (BzS), in environmental water samples is evaluated. After
extraction, analytes were determined by gas chromatography combined with mass spectrometry detection (GC-MS). Parameters potentially
affecting the performance of the sample preparation method (sample pH, ionic strength, type and volume of dispersant and extractant
solvents) were systematically investigated using both multi- and univariant optimization strategies. Under final working conditions,
analytes were extracted from 10 mL water samples by addition of 1 mL of acetone (dispersant) containing 60 μL of chlorobenzene
(extractant), without modifying either the pH or the ionic strength of the sample. Limits of quantification (LOQs) between
2 and 14 ng L−1, inter-day variability (evaluated with relative standard deviations, RSDs) from 9% to 14% and good linearity up to concentrations
of 10,000 ng L−1 were obtained. Moreover, the efficiency of the extraction was scarcely affected by the type of water sample. With the only
exception of 2-ethylhexyl-p-dimethylaminobenzoate (EHPABA), compounds were found in environmental water samples at concentrations between 6 ± 1 ng L−1 and 26 ± 2 ng mL−1. 相似文献
11.
Spínola V Mendes B Câmara JS Castilho PC 《Analytical and bioanalytical chemistry》2012,403(4):1049-1058
This study provides a versatile validated method to determine the total vitamin C content, as the sum of the contents of L-ascorbic acid (L-AA) and dehydroascorbic acid (DHAA), in several fruits and vegetables and its degradability with storage
time. Seven horticultural crops from two different origins were analyzed using an ultra-high-performance liquid chromatographic–photodiode
array (UHPLC-PDA) system, equipped with a new trifunctional high strength silica (100% silica particle) analytical column
(100 mm × 2.1 mm, 1.7 μm particle size) using 0.1% (v/v) formic acid as mobile phase, in isocratic mode. This new stationary phase, specially designed for polar compounds, overcomes
the problems normally encountered in HPLC and is suitable for the analysis of large batches of samples without L-AA degradation.
In addition, it proves to be an excellent alternative to conventional C18 columns for the determination of L-AA in fruits
and vegetables. The method was fully validated in terms of linearity, detection (LOD) and quantification (LOQ) limits, accuracy,
and inter/intra-day precision. Validation experiments revealed very good recovery rate of 96.6 ± 4.4% for L-AA and 103.1 ± 4.8
% for total vitamin C, good linearity with r
2
-values >0.999 within the established concentration range, excellent repeatability (0.5%), and reproducibility (1.6%) values.
The LOD of the method was 22 ng/mL whereas the LOQ was 67 ng/mL. It was possible to demonstrate that L-AA and DHAA concentrations
in the different horticulture products varied oppositely with time of storage not always affecting the total amount of vitamin
C during shelf-life. Locally produced fruits have higher concentrations of vitamin C, compared with imported ones, but vegetables
showed the opposite trend. Moreover, this UHPLC-PDA methodology proves to be an improved, simple, and fast approach for determining
the total content of vitamin C in various food commodities, with high sensitivity, selectivity, and resolving power within
3 min of run analysis. 相似文献
12.
Viñas P López-García I Bravo-Bravo M Briceño M Hernández-Córdoba M 《Analytical and bioanalytical chemistry》2012,403(4):1059-1066
A miniaturized dispersive liquid–liquid microextraction (DLLME) procedure coupled to liquid chromatography (LC) with fluorimetric
detection was evaluated for the preconcentration and determination of thiamine (vitamin B1). Derivatization was carried out by chemical oxidation of thiamine with 5 × 10−5 M ferricyanide at pH 13 to form fluorescent thiochrome. For DLLME, 0.5 mL of acetonitrile (dispersing solvent) containing
90 μL of tetrachloroethane (extraction solvent) was rapidly injected into 10 mL of sample solution containing the derivatized
thiochrome and 24% (w/v) sodium chloride, thereby forming a cloudy solution. Phase separation was carried out by centrifugation, and a volume of
20 μL of the sedimented phase was submitted to LC. The mobile phase was a mixture of a 90% (v/v) 10 mM KH2PO4 (pH 7) solution and 10% (v/v) acetonitrile at 1 mL min−1. An amide-based stationary phase involving a ligand with amide groups and the endcapping of trimethylsilyl was used. Specificity,
linearity, precision, recovery, and sensitivity were satisfactory. Calibration graph was carried out by the standard additions
method and was linear between 1 and 10 ng mL−1. The detection limit was 0.09 ng mL−1. The selectivity of the method was judged from the absence of interfering peaks at the thiamine elution time for blank chromatograms
of unspiked samples. A relative standard deviation of 3.2% was obtained for a standard solution containing thiamine at 5 ng mL−1. The esters thiamine monophosphate and thiamine pyrophosphate can also be determined by submitting the sample to successive
acid and enzymatic treatments. The method was applied to the determination of thiamine in different foods such as beer, brewer’s
yeast, honey, and baby foods including infant formulas, fermented milk, cereals, and purees. For the analysis of solid samples,
a previous extraction step was applied based on an acid hydrolysis with trichloroacetic acid. The reliability of the procedure
was checked by analyzing a certified reference material, pig’s liver (CRM 487). The value obtained was 8.76 ± 0.2 μg g−1 thiamine, which is in excellent agreement with the certified value, 8.6 ± 1.1 μg g−1. 相似文献
13.
A liquid chromatography–mass spectrometry (LC-MS) method was developed and validated for the simultaneous determination of
alisol A and alisol A 24-acetate from Alisma orientale (Sam.) Juz. in rat plasma using diazepam as an internal standard. A 200-μl plasma sample was extracted by methyl tert-butyl ether and the separation was performed on Kromasil C18 column (150 × 4.6 mm, 5 μm) with the mobile phase of acetonitrile (containing 0.1% of formic acid)–water (73:27, v/v) at a flow rate of 0.8 ml/min in a run time of 10 min. The two analytes were monitored with positive electrospray ionization
by selected ion monitoring mode. The lower limit of quantitation for both alisol A and alisol A 24-acetate were 10 ng/ml.
The calibration curves were linear in the measured range 10–1,000 ng/ml for alisol A and 10–500 ng/ml for alisol A 24-acetate.
The mean extraction recoveries were above 74.7% for alisol A and above 72.4% for alisol A 24-acetate from biological matrixes.
The intra- and inter-day precision for all concentrations of quality controls was lower than 14.1% (RSD %) for each analyte.
The accuracy ranged from −12.3% to 9.8% (RE %) for alisol A, and −8.6% to 14.2% (RE %) for alisol A 24-acetate. The method
was successfully applied to the study on the pharmacokinetics of alisol A and alisol A 24-acetate in rat plasma. 相似文献
14.
Chang-Ching Lin Chien-Wen Kuo Li-Heng Pao 《Analytical and bioanalytical chemistry》2010,398(2):857-865
The first liquid chromatography–tandem mass spectrometry method was developed and validated for the simultaneous quantification
of p-aminohippuric acid and inulin, both typical biomarkers of kidney function. 5-(Hydroxymethyl)furfural, generated from inulin
by acid and heat preparation, was used as an inulin substitute for the quantification. Acetaminophen was used as the internal
standard. Solid-phase extraction was carried out with 5% methanol as the washing solution to optimize the retention of the
analytes and to avoid obstruction of the orifice plate of the mass spectrometer caused by any unreacted inulin residue remaining
from the sample preparation process. Chromatography separation was performed on a Symmetry C18 column and a mobile phase composed of 2 mM ammonium formate and 0.1% formic acid in water (solvent A) and 2 mM ammonium formate
and 0.1% formic acid in acetonitrile (solvent B) (30:70, v/v). Detection was performed with a triple-quadrupole tandem mass
spectrometer using positive ion mode electrospray ionization in the multiple reaction monitoring mode. The selected transitions
were m/z 195.2 → 120.2, 127.1 → 109.1, and 152.1 → 110.0 for p-aminohippuric acid, inulin [measured as 5-(hydroxymethyl)furfural], and acetaminophen, respectively. The linearity ranged
from 10 to 140 μg/mL and from 100 to 1,400 μg/mL for p-aminohippurric acid and inulin (r > 0.99), respectively. The precisions and accuracies were all within 12 and 11% for the lower limit of quantification and
quality control samples, respectively. This application was proven to be reliable and accurate and was successfully applied
to a renal function study. 相似文献
15.
In the present study, a rapid and sensitive LC-ESI-MS/MS method for quantification of (S)-fluoxetine as a native marker in mass spectrometry (MS) binding assays addressing the human serotonin transporter (hSERT)
was developed and validated. The concept of MS binding assays based on mass spectrometric quantification of a nonlabeled marker
recently introduced by us represents a promising alternative to conventional radioligand binding without the drawbacks inherently
connected with radioisotope labeling. For high-performance liquid chromatography (HPLC), a 20 × 2-mm RP-18 column with a mobile
phase composed of acetonitrile and ammonium bicarbonate buffer (5 mmol L−1, pH 9.5) at a ratio of 80:20 (v/v) and a flow rate of 800 μL min−1 in an isocratic mode were used, resulting in a chromatographic cycle time of 60 s. Employing [2H5]fluoxetine as internal standard enabled ESI-MS/MS quantification of (S)-fluoxetine between 3 nmol L−1 and 50 pmol L−1 (LLOQ) in matrix obtained from binding experiments without the need of any sample preparation. Validation of the method showed
that linearity, intra-, and inter-batch accuracy as well as precision meet the requirements of the FDA guidance for bioanalytical
method validation. Considering sensitivity and speed, the established method is clearly superior to those published for biological
matrices so far. Furthermore, the method was transferred to other RP-18 columns of different lengths and respective validation
experiments demonstrated its versatility and chromatographic robustness. Finally, the newly developed method was successfully
applied to MS binding assays for hSERT. The affinity determined for (S)-fluoxetine in saturation experiments was in good agreement with literature data obtained in respective radioligand binding
assays. 相似文献
16.
Apichai Santalad Supalax Srijaranai Rodjana Burakham Jeremy D. Glennon Richard L. Deming 《Analytical and bioanalytical chemistry》2009,394(5):1307-1317
A cloud-point extraction (CPE) method using Triton X-114 non-ionic surfactant was developed for the extraction and preconcentration
of carbamate insecticide residues (i.e., methomyl, propoxur, carbofuran, carbaryl, isoprocarb, and promecarb) in fruit samples.
The optimum conditions of CPE were 1.5% (w/v) Triton X-114, 7.0% (w/v) NaCl and 20 min equilibrated at 45 °C. The surfactant-rich phase was then analyzed by reversed-phase high-performance liquid
chromatography with ultraviolet detection at 270 nm, under gradient separation using methanol and 0.1% (v/v) acetic acid. Under the study conditions, six carbamate insecticides were successfully separated within 27 min. Good reproducibility
was obtained with the relative standard deviation of <3% for retention time and <9% for peak area. Limits of detection in
the studied fruit samples were in the range of 0.1–1.0 mg kg−1. No carbamate insecticides were detected in the studied fruit samples. The high recoveries of the spiked fruit samples were
obtained in the range 80.0–107%. The CPE method has been shown to be a potential useful methodology for the preconcentration
of the target analytes, with a preconcentration factor of 14. Moreover, the method is simple, has high sensitivity, consumes
much less solvent than traditional methods, and is environmental friendly. 相似文献
17.
Christina Schiborr Gunter P. Eckert Gerald Rimbach Jan Frank 《Analytical and bioanalytical chemistry》2010,397(5):1917-1925
Curcumin, a lipophilic polyphenol derived from the rhizome of the plant turmeric (Curcuma longa), might be useful in the prevention and treatment of a number of degenerative brain disorders, including glioma multiforma
and Alzheimer’s disease. Thus, there is growing interest in measuring curcumin concentrations in the brain and other target
tissues in relevant animal models. We therefore developed and validated (according to the Food and Drug Administration guidelines
for bioanalytical method validation), a simple, fast and reliable method for the quantification of curcumin in biological
matrices by fast high-performance liquid chromatography with fluorescence detection. This method involves a simple extraction
with 95% ethyl acetate and 5% methanol, rapid separation (<2 min if external standards and <4 min if the internal standard
β-estradiol 17-acetate is used) on a Jasco Reprosil-Pur Basic C18 column (75 × 2 mm, 1.8 μm) with an eluent of acetonitrile, methanol, de-ionised water and acetic acid (49:20:30:1, v/v; flow rate, 0.4 mL/min) and fluorescence detection (excitation wavelength, 420 nm; emission wavelength, 470 nm). The method
is selective, precise (<15% RSD at the lower limit of quantification), accurate (<15% of the coefficient of variation at the
lower limit of quantification) and sensitive over a linear range of 0.05–10 μg/mL for curcumin. The developed method was used
for the quantification of curcumin in the brains of mice force-fed (50 mg/kg bw) or i.p. injected (100 mg/kg bw) with curcumin.
Brain curcumin concentrations of the mice were below the limit of detection at 30, 60 and 120 min after oral gavage and reached
4–5 μg/g brain 20–40 min after i.p. injection. In conclusion, the developed and validated method should be useful for the
accurate and precise quantification of curcumin in target organs from relevant animal models of human diseases. 相似文献
18.
Joan O. Grimalt Mike Howsam Daniel Carrizo Raquel Otero Mary Rosa Rodrigues de Marchi Esther Vizcaino 《Analytical and bioanalytical chemistry》2010,396(6):2265-2272
A rapid, robust and economical method for the analysis of persistent halogenated organic compounds in small volumes of human
serum and umbilical cord blood is described. The pollutants studied cover a broad range of molecules of contemporary epidemiological
and legislative concern, including polychlorobiphenyls (PCBs), polychlorobenzenes (CBs), hexachlorocyclohexanes (HCHs), DDTs,
polychlorostyrenes (PCSs) and polybromodiphenyl ethers (PBDEs). Extraction and clean-up with n-hexane and concentrated sulphuric acid was followed with analysis by gas chromatography coupled to electron capture (GC-ECD)
and GC coupled to negative ion chemical ionisation mass spectrometry (GC-NICI-MS). The advantages of this method rest in the
broad range of analytes and its simplicity and robustness, while the use of concentrated sulphuric acid extraction/clean-up
destroys viruses that may be present in the samples. Small volumes of reference serum between 50 and 1000 μL were extracted
and the limits of detection/quantification and repeatability were determined. Recoveries of spiked compounds for the extraction
of small volumes (≥300 μL) of the spiked reference serum were between 90% and 120%. The coefficients of variation of repeatability
ranged from 0.1–14%, depending on the compound. Samples of 4-year-old serum and umbilical cord blood (n = 73 and 40, respectively) from a population inhabiting a village near a chloro-alkali plant were screened for the above-mentioned
halogenated pollutants using this method and the results are briefly described. 相似文献
19.
Gadzała-Kopciuch R Cendrowski K Cesarz A Kiełbasa P Buszewski B 《Analytical and bioanalytical chemistry》2011,401(7):2069-2078
This study presents a selective method of isolation of zearalenone (ZON) and its metabolite, α-zearalenol (α-ZOL), in neoplastically
changed human tissue by accelerated solvent and ultrasonic extractions using a mixture of acetonitrile/water (84/16% v/v) as the extraction solvent. Extraction effectiveness was determined through the selection of parameters (composition of the
solvent mixture, temperature, pressure, number of cycles) with tissue contamination at the level of nanograms per gram. The
produced acetonitrile/water extracts were purified, and analytes were enriched in columns packed with homemade molecularly
imprinted polymers. Purified extracts were determined by liquid chromatography (LC) coupled with different detection systems
(diode array detection - DAD and mass spectrometry - MS) involving the Ascentis RP-Amide as a stationary phase and gradient
elution. The combination of UE-MISPE-LC (ultrasonic extraction - molecularly imprinted solid-phase extraction - liquid chromatography)
produced high (R ≈ 95–98%) and repeatable (RSD < 3%) recovery values for ZON and α-ZOL. 相似文献
20.
Borges KB de Oliveira AR Barth T Jabor VA Pupo MT Bonato PS 《Analytical and bioanalytical chemistry》2011,399(2):915-925
The purpose of this study was the development and validation of an LC–MS–MS method for simultaneous analysis of ibuprofen
(IBP), 2-hydroxyibuprofen (2-OH-IBP) enantiomers, and carboxyibuprofen (COOH-IBP) stereoisomers in fungi culture medium, to
investigate the ability of some endophytic fungi to biotransform the chiral drug IBP into its metabolites. Resolution of IBP
and the stereoisomers of its main metabolites was achieved by use of a Chiralpak AS-H column (150 × 4.6 mm, 5 μm particle
size), column temperature 8 °C, and the mobile phase hexane–isopropanol–trifluoroacetic acid (95: 5: 0.1, v/v) at a flow rate of 1.2 mL min−1. Post-column infusion with 10 mmol L−1 ammonium acetate in methanol at a flow rate of 0.3 mL min−1 was performed to enhance MS detection (positive electrospray ionization). Liquid–liquid extraction was used for sample preparation
with hexane–ethyl acetate (1:1, v/v) as extraction solvent. Linearity was obtained in the range 0.1–20 μg mL−1 for IBP, 0.05–7.5 μg mL−1 for each 2-OH-IBP enantiomer, and 0.025–5.0 μg mL−1 for each COOH-IBP stereoisomer (r ≥ 0.99). The coefficients of variation and relative errors obtained in precision and accuracy studies (within-day and between-day)
were below 15%. The stability studies showed that the samples were stable (p > 0.05) during freeze and thaw cycles, short-term exposure to room temperature, storage at −20 °C, and biotransformation
conditions. Among the six fungi studied, only the strains Nigrospora sphaerica (SS67) and Chaetomium globosum (VR10) biotransformed IBP enantioselectively, with greater formation of the metabolite (+)-(S)-2-OH-IBP. Formation of the COOH-IBP stereoisomers, which involves hydroxylation at C3 and further oxidation to form the
carboxyl group, was not observed. 相似文献