共查询到20条相似文献,搜索用时 31 毫秒
1.
A novel molecularly imprinted polymer solid-phase extraction (MISPE) with flow-injection chemiluminescence (CL) was developed
for the determination of pazufloxacin mesilate (PZFX). The molecularly imprinted polymer (MIP) was synthesized by using PZFX
as the imprinting molecule. A glass tube packed the particles of the MIP was employed as MISPE micro-column, which was connected
into the sampling loop of the eight-way injection valve for on-line selective preconcentration and extraction of PZFX. The
eluent of acetonitrile:acetic acid (9:1, v:v) was used as carrier for eluting the adsorbed PZFX to react with the mixture
of cerium(IV) and sodium sulfite in the flow cell to produce strong CL. The relative intensity of CL was linear to PZFX concentration
in the range from 2.5 × 10−9 to 2.5 × 10−7 g mL−1. The limit of detection was 7 × 10−10 g mL−1 (3 σ) and the relative standard deviation for 5 × 10−8 g mL−1of PZFX solution was 3.7% (n = 7). This method has been applied to the determination of PZFX in human urine. 相似文献
2.
A novel method for rapid HPLC-ICP-MS analysis of oxaliplatin in human urine was developed implementing a stationary HPLC phase
with a particle size of 1.8 μm. The method allowed a cycle time of <1 min at a HPLC flow rate of 0.9 mL min−1. Procedural limits of detection of 0.05 μg L−1 oxaliplatin (150 fg on column) were obtained. Analysis of oxaliplatin in patient urine showed that accurate quantification
of the intact drug demanded for storage at −80 °C and rapid measurement after thawing. 相似文献
3.
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
4.
This work reported for the first time the use of flow injection electrochemiluminescence (FI-ECL) sensor for the determination
of durabolin in an aqueous system based on CdTe quantum dot (QD) films. Aqueous CdTe colloidal solutions were prepared using
thioglycolic acid as a capping agent. Zetasizer Nano ZS (Malvern, UK) was employed to characterize the size of CdTe QDs. The
UV–vis and photoluminescence spectra of samples were systematically characterized. Indium tin oxide (ITO) slide glass was
modified with CdTe QDs by layer-by-layer self-assembly. CdTe QD films were packed into a homemade cell and used as a recognizer
of the FI-ECL sensor to determine durabolin. The intensive anodic ECL emission was obtained at a starting potential of +1.3 V
(vs. Ag/AgCl) in a carbonate bicarbonate buffer solution with a pH of 9.93 at an ITO electrode. The ECL intensity was correlated
linearly with the concentration of durabolin over the range of 1.0 × 10−8–1.0 × 10−5 g mL−1, and the detection limit was 2.5 × 10−9 g mL−1. The relative standard deviation for the determination of 1.0 × 10−6 g mL−1 durabolin was 1.04% (n = 11). This simple and sensitive sensor revealed good reproducibility for ECL analysis. As a result, the new FI-ECL sensor
had been successfully applied to the determination of durabolin in food samples. This strategy could be easily realized and
opened new avenues for the applications of QDs in ECL biosensing. 相似文献
5.
Jorge L. Guzmán Mar Leticia López Martínez Pedro L. López de Alba Nancy Ornelas Soto Víctor Cerdà Martín 《Journal of Radioanalytical and Nuclear Chemistry》2009,281(3):433-439
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
6.
Sangita Pal Suchismita Mishra S. K. Satpati G. G. Pandit P. K. Tewari V. D. Puranik 《Journal of Radioanalytical and Nuclear Chemistry》2011,289(1):67-73
A fast and simple multisyringe flow injection analysis (MSFIA) method for routine determination of thorium in water samples
was developed. The methodology was based on the complexation reaction of thorium with arsenazo (III) at pH 2.0. Thorium concentrations
were spectrophotometrically detected at 665 nm. Under optimal conditions, Beer’s law was obeyed over the range from 0.2 to
4.5 μg mL−1 thorium, a 3σ detection limit of 0.05 μg mL−1, and a 10σ quantification limit of 0.2 μg mL−1 were obtained. The relative standard deviations (RSD, %) at 0.5, 2.5 and 4.5 μg mL−1 was 2.8, 1.5 and 0.8%, respectively (n = 10). It was found that most of the common metal ions and anions did not interfere with the thorium determination. The proposed
method was successfully applied to its analysis in various water samples. 相似文献
7.
Leveriza F. Arenas Benilda S. Ebarvia Fortunato B. Sevilla III 《Analytical and bioanalytical chemistry》2010,397(7):3155-3158
A piezoelectric quartz crystal (PQC) sensor based on a molecularly imprinted polymer (MIP) has been developed for enantioselective
and quantitative analysis of d-(+)-methamphetamine (d(+)-MA). The sensor was produced by bulk polymerization and the resulting MIP was then coated on the
gold electrode of an AT-cut quartz crystal. Conditions such as volume of polymer coating, curing time, type of PQC, baseline
solvent, pH, and buffer type were found to affect the sensor response and were therefore optimized. The PQC-MIP gave a stable
response to different concentrations of d(+)-MA standard solutions (response time = 10 to 100 s) with good repeatability (RSD = 0.03
to 3.09%; n = 3), good reproducibility (RSD = 3.55%; n = 5), and good reversibility (RSD = 0.36%; n = 3). The linear range of the sensor covered five orders of magnitude of analyte concentration, ranging from 10−5 to 10−1 μg mL−1, and the limit of detection was calculated as 11.9 pg d(+)-MA mL−1
. The sensor had a highly enantioselective response to d(+)-MA compared with its response to l(−)-MA, racemic MA, and phentermine.
The developed sensor was validated by applying it to human urine samples from drug-free individuals spiked with standard d(+)-MA
and from a confirmed MA user. Use of the standard addition method (SAM) and samples spiked with d(+)-MA at levels ranging
from 1 × 10−3 to 1 × 10−2 μg mL−1 showed recovery was good (95.3 to 110.9%). 相似文献
8.
Determination of nine high-intensity sweeteners in various foods by high-performance liquid chromatography with mass spectrometric detection 总被引:1,自引:0,他引:1
Zygler A Wasik A Kot-Wasik A Namieśnik J 《Analytical and bioanalytical chemistry》2011,400(7):2159-2172
An analytical procedure involving solid-phase extraction (SPE) and high-performance liquid chromatography-mass spectrometry
has been developed for the determination of nine high-intensity sweeteners authorised in the EU; acesulfame-K (ACS-K), aspartame
(ASP), alitame (ALI), cyclamate (CYC), dulcin (DUL), neohesperidin dihydrochalcone (NHDC), neotame (NEO), saccharin (SAC)
and sucralose (SCL) in a variety of food samples (i.e. beverages, dairy and fish products). After extraction with a buffer
composed of formic acid and N,N-diisopropylethylamine at pH 4.5 in ultrasonic bath, extracts were cleaned up using Strata-X 33 μm Polymeric SPE column. The
analytes were separated in gradient elution mode on C18 column and detected by mass spectrometer working with an electrospray source in negative ion mode. To confirm that analytical
method is suitable for its intended use, several validation parameters, such as linearity, limits of detection and quantification,
trueness and repeatibilty were evaluated. Calibration curves were linear within a studied range of concentrations (r
2
≥ 0.999) for six investigated sweeteners (CYC, ASP, ALI, DUL, NHDC, NEO). Three compounds (ACS-K, SAC, SCL) gave non-linear
response in the investigated concentration range. The method detection limits (corresponding to signal-to-noise (S/N) ratio
of 3) were below 0.25 μg mL−1 (μg g−1), whereas the method quantitation limits (corresponding to S/N ratio of 10) were below 2.5 μg mL−1 (μg g−1). The recoveries at the tested concentrations (50%, 100% and 125% of maximum usable dose) for all sweeteners were in the
range of 84.2 ÷ 106.7%, with relative standard deviations <10% regardless of the type of sample matrix (i.e. beverage, yoghurt,
fish product) and the spiking level. The proposed method has been successfully applied to the determination of the nine sweeteners
in drinks, yoghurts and fish products. The procedure described here is simple, accurate and precise and is suitable for routine
quality control analysis of foodstuffs. 相似文献
9.
A simple, rapid, selective, sensitive and economical method has been developed for the simultaneous determination of trace
amounts of palladium and nickel in aqueous methanolic medium using 2-(2-thiazolylazo)-5-dimethylam inobenzoic acid as an analytical
reagent by first derivative spectrophotometr y. Palladium is determined by measuring base to peak distance at λ=695.0 nm while
nickel is estimated by zero crossing method in the mixture. The linearity is maintained between 0.12–1.75 μg mL−1 for palladium and 0.07–1.60 μg mL−1 for nickel in the pH range 2.8–7.2 and 3.4–8.8 respectively. Seven replicate determinations of 1.0 μ g mL−1 of palladium and 0.8 μg mL−1 of nickel in a mixture give a mean signal height of 0.391 for Pd and 0.541 for Ni with relative standard deviations of 0.9%
and 1.2%, respectively. The sensitivity of the proposed method is 0.391 (dA/dλ)/(μg mL−1) for palladium and 0.685 (dA/dλ)/(μg mL−1) for nickel. Various parameters have been optimised for the simultaneous determination of palladium and nickel in various
complex samples.
Received March 30, 1999. Revision November 25, 1999. 相似文献
10.
González-Andrade M Benito-Peña E Mata R Moreno-Bondi MC 《Analytical and bioanalytical chemistry》2012,402(10):3211-3218
This paper describes the development of a novel on-line biosensor based on a fluorescently labeled human calmodulin (CaM),
hCaM M124C-mBBr, immobilized on controlled-pore glass (CPG), for the analysis of trifluoroperazine (TFP); a phenothiazine drug in human urine
samples. The device was automated by packing hCaM M124C-mBBr-CPG in a continuous-flow microcell connected to a monitoring system, composed of a bifurcated optical fiber coupled to a
spectrofluorometer. Operating parameters of the on-line biosensor (flow rate, sample injection volume, and carrier solution
and buffer pH) were studied and optimized. Under the optimal conditions, the biosensor provides a detection and a quantification
limit of 0.24 and 0.52 μg mL−1, respectively, and a dynamic range from 0.52 to 61.05 μg mL−1 TFP (n = 5, correlation coefficient 0.998). The response time (t
100) was shorter than 42 s (recovery time <4.5 min) and reproducibility and repeatability of the TFP measurements, within the
linear response range, were lower than 1.4 and 2.7%, respectively. The device was successfully applied to the analysis of
TFP in spiked human urine samples with recoveries ranging between 97 and 101% and with RSDs lower than 5.9%. 相似文献
11.
Ming-Zhou Zhang Min-Zi Wang Zong-Lun Chen Jie-Hong Fang Mei-Ming Fang Jun Liu Xiao-Ping Yu 《Analytical and bioanalytical chemistry》2009,395(8):2591-2599
A multianalyte lateral-flow immunochromatographic technique using colloidal gold-labeled polyclonal antibodies was developed
for the rapid simultaneous detection of clenbuterol and ractopamine. The assay procedure could be accomplished within 5 min,
and the results of this qualitative one-step assay were evaluated visually according to whether test lines appeared or not.
When applied to the swine urines, the detection limit and the half maximal inhibitory concentration (IC50) of the test strip under an optical density scanner were calculated to be 0.1 ± 0.01 ng mL−1 and 0.1 ± 0.01 ng mL−1, 0.56 ± 0.08 ng mL−1, and 0.71 ± 0.06 ng mL−1, respectively, the cut-off levels with the naked eye of 1 ng mL−1 and 1 ng mL−1 for clenbuterol and ractopamine were observed. Parallel analysis of swine urine samples with clenbuterol and ractopamine
showed comparable results obtained from the multianalyte lateral-flow test strip and GC-MS. Therefore, the described multianalyte
lateral-flow test strip can be used as a reliable, rapid, and cost-effective on-site screening technique for the simultaneous
determination of clenbuterol and ractopamine residues in swine urine.
相似文献
12.
Abdel-Aziz Youssef El-Sayed Ebtesam Ahmad Saad Basheer Mohamed Mohamed Ibrahime Mohamed Tarek Mohamed Zaki 《Mikrochimica acta》2000,135(1-2):19-27
Simple, rapid, sensitive and selective methods for the determination of Cr(III) and W(VI) with flavonol derivatives in the
presence of surface-active agents are proposed. In the pH ranges 3.4–4.2 and 1.9–2.5, the molar absorptivities of Cr(III)-morin-emulsifier
S (EFA) and W(VI)-morin-polyvinylpyrrolidone (PVP) systems are 1.13×105 and 2.13×104 L mol−1 cm−1 at 435 and 415 nm, respectively. The Cr(III)-quercetin-PVP and W(VI)-quercetin-cetylpyridinium bromide (CPB) systems are
formed in the pH ranges 4–4.6 and 2.2–2.8 with molar absorptivities 1.02×105 and 9.02×104 L. mol−1 cm−1 at 441 and 419 nm, respectively. The linear dynamic ranges for the determination of Cr(III) and W(VI) with morin in the presence
of EFA and PVP are 0.03–0.46 and 0.71–8.1 μg mL−1, respectively. The corresponding ranges with quercetin are 0.04–0.54 and 0.14–2.1 μg mL−1 of Cr(III) and W(VI), respectively. The r.s.d (n = 10) for the determination of 0.25 and 3.7 μg mL−1 of Cr(III) and W(VI) with morin and their detection limits are 0.88 and 0.99% and 0.016 and 0.63 μg mL−1, respectively. Using quercetin, the r.s.d (n = 10) for 0.22 and 1.2 μg mL−1 of Cr(III) and W(VI) and their detection limits are 0.92 and 0.91% and 0.015 and 0.08 μg mL−1, respectively. The critical evaluation of the proposed methods is performed by statistical analysis of the experimental data.
The proposed methods are applied to determine Cr in steel, non-ferrous alloys, wastewater and mud filtrate and to the determination
of W in steel.
Received March 8, 1999. Revision January 21, 2000. 相似文献
13.
Liu X Xu J Li Y Dong F Li J Song W Zheng Y 《Analytical and bioanalytical chemistry》2011,399(7):2539-2547
A sensitive and effective method for simultaneous determination of triazolopyrimidine sulfonamide herbicide residues in soil,
water, and wheat was developed using ultra-performance liquid chromatography coupled with tandem mass spectrometry. The four
herbicides (pyroxsulam, flumetsulam, metosulam, and diclosulam) were cleaned up with an off-line C18 SPE cartridge and detected
by tandem mass spectrometry using an electrospray ionization source in positive mode (ESI+). The determination of the target
compounds was achieved in <2.0 min. The limits of detection were below 1 μg kg−1, while the limits of quantification did not exceed 3 μg kg−1 in different matrices. Quantitation was determined from calibration curves of standards containing 0.05–100 μg L−1 with r
2 > 0.997. Recovery studies were conducted at three spiked levels (0.2, 1, and 5 μg kg−1 for water; 5, 10, and 100 μg kg−1 for soil and wheat). The overall average recoveries for this method in water, soil, wheat plants, and seeds at three levels
ranged from 75.4% to 106.0%, with relative standard deviations in the range of 2.1–12.5% (n = 5) for all analytes. 相似文献
14.
The worldwide contamination of winery by-products by mycotoxins may present a serious hazard to human and animal health. Mycotoxins
are secondary metabolites of fungi with possible adverse effects on humans, animals, and crops that result in illnesses and
economic losses. Mycotoxins are under continuous survey in Europe, but the regulatory aspects still need to be set up for
winery by-products, which may be used in animal feed. The aim of this study was to implement a simple but reliable analytical
methodology for ochratoxin A (OTA) quantification in grape pomaces in order to perform a survey of samples from the Douro
Demarcated Region, Portugal. The method involved a unique preparation step, solvent extraction, followed by high-performance
liquid chromatography (HPLC) with fluorescence (FL) detection. A comparative study was performed with two extraction solvents
(ethyl acetate and methanol) as well as using extraction on an immunoaffinity column. The linearity range for OTA analysis
was 0.05–23.5 μg L−1 with a detection limit of 0.05 μg L−1 and a precision (expressed by the coefficient of variation under repeatability conditions) of 0.4–14.7%. The percentage of
recovery was on average 23.5 ± 3.6% (extraction with ethyl acetate) or 70.1 ± 2.5% (extraction with 70% methanol). Accounting
for the recovery factor and the chromatographic detection limit, as well as the preconcentration factor, the limit of detection
in grape pomaces is 0.04 μg kg−1 (ethyl acetate extraction) and 0.33 μg kg−1 (methanol extraction). Samples from 12 out of 13 sites in the Douro Demarcated Region showed OTA presence with concentrations
not exceeding 0.4 μg kg−1. Both developed methods for evaluation of OTA in grape pomace are simple but efficient.
Figure Extraction of ochratoxin A (OTA) from grape pomaces allows simple but efficient quantification of OTA in winery by-products
by HPLC-FL 相似文献
15.
Cooper EM Covaci A van Nuijs AL Webster TF Stapleton HM 《Analytical and bioanalytical chemistry》2011,401(7):2123-2132
Organophosphate triesters tris(1,3-dichloro-2-propyl) phosphate (TDCPP) and triphenyl phosphate are widely used flame retardants
(FRs) present in many products common to human environments, yet understanding of human exposure and health effects of these
compounds is limited. Monitoring urinary metabolites as biomarkers of exposure can be a valuable aid for improving this understanding;
however, no previously published method exists for the analysis of the primary TDCPP metabolite, bis(1,3-dichloro-2-propyl)
phosphate (BDCPP), in human urine. Here, we present a method to extract the metabolites BDCPP and diphenyl phosphate (DPP)
in human urine using mixed-mode anion exchange solid phase extraction and mass-labeled internal standards with analysis by
atmospheric pressure chemical ionization liquid chromatography tandem mass spectrometry. The method detection limit was 8 pg mL−1 urine for BDCPP and 204 pg mL−1 for DPP. Recoveries of analytes spiked into urine ranged from 82 ± 10% to 91 ± 4% for BDCPP and from 72 ± 12% to 76 ± 8%
for DPP. Analysis of a small number of urine samples (n = 9) randomly collected from non-occupationally exposed adults revealed the presence of both BDCPP and DPP in all samples.
Non-normalized urinary concentrations ranged from 46–1,662 pg BDCPP mL−1 to 287–7,443 pg DPP mL−1, with geometric means of 147 pg BDCPP mL−1 and 1,074 pg DPP mL−1. Levels of DPP were higher than those of BDCPP in 89% of samples. The presented method is simple and sufficiently sensitive
to detect these FR metabolites in humans and may be applied to future studies to increase our understanding of exposure to
and potential health effects from FRs. 相似文献
16.
Larivière D Tremblay M Durand-Jézéquel M Tolmachev S 《Analytical and bioanalytical chemistry》2012,403(2):409-418
This article describes a robust methodology using the combination of instrumental design (high matrix interface—HMI), sample
dilution and internal standardization for the quantification of beryllium (Be) in various digested autopsy tissues using inductively
coupled plasma mass spectrometry. The applicability of rhodium as a proper internal standard for Be was demonstrated in three
types of biological matrices (i.e., femur, hair, lung tissues). Using HMI, it was possible to achieve instrumental detection
limits and sensitivity of 0.6 ng L−1 and 157 cps L ng−1, respectively. Resilience to high salt matrices of the HMI setup was also highlighted using bone mimicking solution ([Ca2+] = 26 to 1,400 mg L−1), providing a 14-fold increase in tolerance and a 2.7-fold decrease in method detection limit compared to optimized experimental
conditions obtained without the HMI configuration. Precision of the methodology to detect low levels of Be in autopsy samples
was demonstrated using hair and blood certified reference materials. Be concentration ranging from 0.015 to 255 μg kg−1 in autopsy samples obtained from the U.S. Transuranium and Uranium Registries were measured using the methodology presented. 相似文献
17.
Yan Liang Jie Sun Lin Xie An Kang Yuan Xie Wei-Dong Chen Hua Lv Guang-Ji Wang 《Chromatographia》2007,66(3-4):165-170
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 C18 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
18.
A sensitive catalytic method is developed for the spectrophotometric determination of oxalic acid. It is based on the catalytic
action of oxalic acid on a new indicator reaction – the oxidation of Bromophenol Blue by dichromate in dilute sulfuric acid
medium. The reaction rate is monitored spectrophotometrically by measuring the absorbance at 600 nm after quenching the reaction
with sodium hydroxide. A calibration graph from 0.1 to 8.0 μg mL−1 of oxalic acid and a detection limit of 0.04 μg mL−1 was obtained. The applicability of this method was demonstrated by the determination of oxalic acid in water extracts from
vegetables such as spinach, mushrooms and fresh kidney beans.
Received October 18, 1999. Revision June 14, 2000. 相似文献
19.
Hong WK Rairakhwada D Seo PS Park SY Hur BK Kim CH Seo JW 《Applied biochemistry and biotechnology》2011,164(8):1468-1480
In the present study, a novel oleaginous Thraustochytrid containing a high content of docosahexaenoic acid (DHA) was isolated
from a mangrove ecosystem in Malaysia. The strain identified as an Aurantiochytrium sp. by 18S rRNA sequencing and named KRS101 used various carbon and nitrogen sources, indicating metabolic versatility. Optimal
culture conditions, thus maximizing cell growth, and high levels of lipid and DHA production, were attained using glucose
(60 g l−1) as carbon source, corn steep solid (10 g l−1) as nitrogen source, and sea salt (15 g l−1). The highest biomass, lipid, and DHA production of KRS101 upon fed-batch fermentation were 50.2 g l−1 (16.7 g l−1 day−1), 21.8 g l−1 (44% DCW), and 8.8 g l−1 (40% TFA), respectively. Similar values were obtained when a cheap substrate like molasses, rather than glucose, was used
as the carbon source (DCW of 52.44 g l−1, lipid and DHA levels of 20.2 and 8.83 g l−1, respectively), indicating that production of microbial oils containing high levels of DHA can be produced economically when
the novel strain is used. 相似文献
20.
A rapid, ultra high-performance liquid chromatographic (UHPLC) method has been developed and validated for simultaneous identification
and analysis of the isoflavones genistein, daidzein, glycitin, puerarin, and biochanin A, and the flavonoids (±)-catechin,
(−)-epicatechin, rutin, hesperidin, neohesperidin, quercitrin, and hesperetin in human urine. Urine samples were incubated
with β-glucuronidase/sulfatase. UHPLC was performed with a Hypersil Gold (50 × 2.1 mm, 1.9 μm) analytical column. Elution
was with a gradient prepared from aqueous trifluoroacetic acid (0.05%) and acetonitrile. UV detection was performed at 254
and 280 nm. The calibration curves were indicative of good linearity (r
2 ≥ 0.9992) in the range of interest for each analyte. LODs ranged between 15.4 and 107.0 ng mL−1 and 3.9 and 20.4 ng mL−1 for flavonoids and isoflavones, respectively. Intra-day and inter-day precision (C.V., %) was less than 3.9% and 3.8%, respectively,
and accuracy was between 0.03% and 5.0%. Recovery was 70.35–96.58%. The method is very rapid, simple, and reliable, and suitable
for pharmacokinetic analysis. It can be routinely used for simultaneous determination of these five isoflavones and seven
flavonoids in human urine. The method can also be applied to studies after administration of pharmaceutical preparations containing
isoflavones and flavonoids to humans. 相似文献