共查询到20条相似文献,搜索用时 15 毫秒
1.
A simple flow-injection chemiluminescence method with synergistic enhancement has been investigated for the rapid and sensitive
determination of antipsychotic risperidone. The synergistic action was significant in the chemiluminescence system of luminol—hydrogen
peroxide with risperidone as an enhancer. The increased chemiluminescence intensity was correlated with risperidone concentration
within the range from 10 pg mL−1 to 1.0 ng mL−1 with relative standard deviations lower than 5.0 % and the detection limit of 4 pg mL−1. At a flow rate of 2.0 mL min−1, the flow-injection chemiluminescence method exhibited both a high sensitivity and excellent selectivity giving a throughput
of 120 times per hour. The proposed method was successfully applied to determine the risperidone content in human urine without
any pretreatment. It was found that the excretive amounts of risperidone reached their maximum after taking 2.0 mg of risperidone
for 1 h, with a total excretive ratio of 17.37 % in 8.5 h. 相似文献
2.
The chemiluminescence (CL) of peracetic acid (PAA) in alkaline medium is very weak but is strongly enhanced after the addition
of dihydralazine sulfate (DHZS). Based on this phenomenon, a simple, rapid and highly sensitive flow-injection CL method for
the determination of DHZS was developed. The CL emission was linearly related to the DHZS concentration in the range of 20–4000 ng mL−1 with a detection limit (3σ) of 1.2 ng mL−1. As a preliminary application, the proposed method was successfully applied to the determination of DHZS in pharmaceutical
preparations; the recovery of DHZS in human urine was between 96.5% and 102.2%. A detailed CL mechanism was proposed and singlet
molecular oxygen (1O2) was suggested to be produced in the CL reaction process. 相似文献
3.
A novel method for the determination of proteins at nanogram levels was proposed based on the decrease of resonance light
scattering (RLS) signal resulting from the interaction of dibromo-o-nitrophenylfluorone (DBONPF)-sodium lauroyl glutamate
(SLG) with proteins. At pH 2.97, the decrease RLS intensity was proportional to the concentration of proteins in the range
of nanogram levels with 3σ detection limits being 3.4 ng mL−1 for bovine serum albumin (BSA), 1.7 ng mL−1 for human serum albumin (HSA), 4.1 ng mL−1 for γ-globulin (γ-IgG), 4.4 ng mL−1 for egg albumin, 6.2 ng mL−1 for pepsin (Pep) and 3.7 ng mL−1 for α-chymotrypsin (Chy). The method is no protein-to-protein variability, simple, rapid, practical and relatively free
from interference from coexisting substance, as well as much more sensitive than most of the reported methods. The proposed
method was successfully applied to determine total protein in human serum samples. 相似文献
4.
Akhmad Sabarudin Osamu Noguchi Mitsuko Oshima Keiro Higuchi Shoji Motomizu 《Mikrochimica acta》2007,159(3-4):341-348
Chitosan resin functionalized with 3,4-dihydroxy benzoic acid (CCTS-DHBA resin) was used as a packing material for flow injection
(FI) on-line mini-column preconcentration in combination with inductively coupled plasma-atomic emission spectrometry (ICP-AES)
for the determination of trace elements such as silver, bismuth, copper, gallium, indium, molybdenum, nickel, uranium, and
vanadium in environmental waters. A 5-mL aliquot of sample (pH 5.5) was introduced to the minicolumn for the adsorption/preconcentration
of the metal ions, and the collected analytes on the mini-column were eluted with 2 M HNO3, and the eluates was subsequently transported via direct injection to the nebulizer of ICP-AES for quantification. The parameters
affecting on the sensitivity, such as sample pH, sample flow rate, eluent concentration, and eluent flow rate, were carefully
examined. Alkali and alkaline earth metal ions commonly existing in river water and seawater did not affect the analysis of
metals. Under the optimum conditions, the method allowed the determination of metal ions with detection limits of 0.08 ng mL−1 (Ag), 0.9 ng mL−1 (Bi), 0.07 ng mL−1 (Cu), 0.9 ng mL−1 (Ga), 0.9 ng mL−1 (In), 0.08 ng mL−1 (Mo), 0.09 ng mL−1 (Ni), 0.9 ng mL−1 (U), and 0.08 ng mL−1 (V). By using 5 mL of sample solution, the enrichment factor and collection efficiency were 8–12 fold and 96–102%, respectively,
whereas the sample throughput was 7 samples/hour. The method was validated by determining metal ions in certified reference
material of river water (SLRS-4) and nearshore seawater (CASS-4), and its applicability was further demonstrated to river
water and seawater samples. 相似文献
5.
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
6.
Andreas Rahm Evgeni M. Kaidashev Heidemarie Schmidt Mariana Diaconu Andreas Pöppl Rolf Böttcher Christoph Meinecke Tilman Butz Michael Lorenz Marius Grundmann 《Mikrochimica acta》2006,153(1-2):21-25
A flow injection chemiluminescence method is proposed for the determination of cobalt, based on the strong catalytic effect
of Cobalt(II) (1,10-phenanthroline)3 complex on the lucigenin-periodate reaction in alkaline medium. Under the optimum experimental conditions, the chemiluminescence
signal responded linearly to the concentration of cobalt(II) in the 1.0 × 10−9–3.0 × 10−7 g mL−1 range with a detection limit of 4.4 × 10−10 g mL−1 cobalt(II). The relative standard deviation for the determination of 5.0 × 10−8 g mL−1 of cobalt was 2.3% in eleven replicated measurements. The method was successfully applied to the determination of cobalt(II)
in pharmaceutical preparations. 相似文献
7.
A new chemiluminescence (CL) method combined with flow injection technique is described for the determination of Cr(III) and
total Cr. It is found that a strong CL signal is generated from the reaction of Cr(III), lucigenin and KIO4 in alkaline condition. The determination of total Cr is performed by pre-reduction of Cr(VI) to Cr(III) by using H2SO3. The CL intensity is linearly related to the concentration of Cr in the range 4.0 × 10−10–1.0 × 10−6 g mL−1. The detection limit (3s
b) is 1 × 10−10 g mL−1 Cr and the relative standard deviation is 1.9% (5.0 × 10−8 g mL−1 of Cr(III) solution, n = 11). The method was applied to the determination of Cr(III) and total Cr in water samples and compared satisfactorily with
the official method. 相似文献
8.
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
9.
CdTe quantum dots (QDs) were modified with thioglycolic acid (TGA) and synthesized in aqueous medium. The optimum fluorescence
intensity was found to be at pH 6.24 with a CdTe QDs concentration of 4.96 × 10−7 mol L−1. The quenched fluorescence intensity of CdTe QDs is linearly proportional to V(V) concentration from 10 to 200 ng mL−1 with correlation coefficient R = 0.9985. The limit of detection for V(V) was 2.07 ng mL−1. The proposed method was successfully applied to the analysis of trace amounts of V(V) in water samples with recovery of
96.5–101.8%, and the results were in good agreement with those of electrothermal atomic absorption spectrometry. 相似文献
10.
Development of a cloud point extraction and preconcentration method for silver prior to flame atomic absorption spectrometry 总被引:1,自引:0,他引:1
The possibility was investigated of using 2-mercaptobenzothiazole (MBT) for Ag(I) concentration by micellar extraction at
cloud point (CP) temperature and subsequent determination by flame atomic absorption spectrometry (FAAS). The method is based
on the complexation of Ag(I) with 2-mercaptobenzothiazole (MBT) in the presence of non-ionic micelles of Triton X-114. The
effect of experimental conditions such as pH, concentration of chelating agent and surfactant, equilibration temperature and
time on cloud point extraction was studied. Under the optimum conditions, the preconcentration of 10 mL of water sample in
the presence of 0.1% Triton X-114 and 2 × 10−4 mol L−1 2-mercaptobenzothiazole permitted the detection of 2.2 ng mL−1 silver. The calibration graph was linear in the range of 10–200 ng mL−1, and the recovery of more than 99% was achieved. The proposed method was used in FAAS determination of Ag(I) in water samples. 相似文献
11.
Simple and rapid fluorometric screening methods have been developed based on the competitive binding between the target and
an intercalating fluorophore dye to double-stranded-DNA (dsDNA). In this study, the long-wavelength fluorescente dye TOTO-3
was employed as the indicator. Compounds that interact with dsDNA will affect the binding of TOTO-3 to the nucleic acid thereby
changing the fluorescence intensity. The analyte concentration is indirectly determined by the decrease in fluorescence intensity.
A fiber optic fluorescence screening system was developed for rapid and convenient sample processing. Lambda DNA (48.5 kb)
was chosen as a suitable sensing nucleic acid material. Detection of sulfathiazole and chloramphenicol in shrimps using this
method was studied in the range of 0.5–25 ng mL−1 of sulfathiazole and of 1–50 ng mL−1 of chloramphenicol. Detection limits of 0.5 ng mL−1 of sulfathiazole and 1 ng mL−1 of chloramphenicol were achieved. This approach is useful as a routine test in the monitoring of antibiotics in the environment
or aquaculture products. The easy operation and the rapid and sensitive detection make this a potential high-throughput screening
method. 相似文献
12.
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
13.
Ning Zhang Qing-Cheng Kong Zhen-Zhen Chen Ke-Hua Xu Bo Tang 《Mikrochimica acta》2007,158(1-2):165-171
A sensitive catalytic kinetic spectrofluorimetric approach for determining ng mL−1 levels of rhodium is presented, and the possible mechanism of the catalytic reaction was investigated. The determination
is based on the catalytic property of rhodium to enhance the reaction of o-vanillin salicylhydrazone (OVSH) with potassium
bromate in a water-ethanol medium at pH 4.80 and 45 °C. The presence of β-cyclodextrin (β-CD) obviously sensitized the assay
due to its high inclusion ability towards OVSH. Under optimized experimental conditions, fluorescence measurements of the
β-CD-rhodium-KBrO3-OVSH catalytic kinetic reaction system were carried out in its fluorescent band centered at λex = 333 nm and λem = 476 nm, respectively. The calibration graph was linear over the concentration range of 0.47–100 ng mL−1 with a detection limit of 0.14 ng mL−1. The effect of interferences was discussed, and the results show that the extraction method can be used to separate rhodium
from interference species such as iridium. The proposed method, applied to several synthetic mixtures containing rhodium mixed
with varying amounts of metal salts, produced satisfactory results. 相似文献
14.
Bagheri H Aghakhani A Akbari M Ayazi Z 《Analytical and bioanalytical chemistry》2011,400(10):3607-3613
A micro-solid phase extraction technique was developed using a novel polypyrrole-polyamide nanofiber sheet, fabricated by
electrospinning method. The applicability of the new nanofiber sheet was examined as an extracting medium to isolate malathion
as a model pesticide from aqueous samples. Solvent desorption was subsequently performed in a microvial, and an aliquot of
extractant was injected into gas chromatography–mass spectrometry. Various parameters affecting the electrospinning process
including monomer concentration, polyamide content, applied voltage, and electrospinning time were examined. After fabricating
the most suitable preparation conditions, influential parameters on the extraction and desorption processes were optimized.
The developed method proved to be rather convenient and offers sufficient sensitivity and good reproducibility. The limit
of detection (S/N = 3) and limit of quantification (S/N = 10) of the method under optimized conditions were 50 and 100 ng L−1, respectively. The relative standard deviation at concentration level of 1 ng mL−1 was 2% (n = 3). The calibration curve of analyte showed linearity in the range of 0.1–1 ng mL−1 (R
2 = 0.9975). The developed method was successfully applied to tap and Zayanderood river water samples, while the relative recovery
percentages of 98% and 96% were obtained, respectively. The whole procedure showed to be conveniently applicable and quite
easy to be manipulated. 相似文献
15.
A simple flow injection chemiluminescence (CL) method was developed for the determination of atenolol using Eu3+ as the probe. It was found that the weak CL generated by the KMnO4-Na2SO3 reaction can be significantly enhanced by the atenolol-Eu3+ complex. The experimental conditions were optimized. The CL intensity was linearly related to atenolol concentration in the
range from 8.0 × 10−9 to 1.0 × 10−5 g mL−1. The detection limit (3s
b) was 3 × 10−9 g mL−1 and the relative standard deviation for 1.0 × 10−7 g mL−1 atenolol solution was 2.4% (n = 11). The method has high sensitivity, wide linear range, inexpensive instrumentation, and has been applied to the determination
of atenolol in spiked human urine and plasma samples with recoveries within the range 95.5–104.0%.
Supplementary material to this paper is available in electronic form at
Electronic supplementary material: Discussion of the reaction mechanism and additional figures are available online as electronic
supplementary material (ESM) at .
Correspondence: Jianxiu Du, Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, School of Chemistry
and Materials Science, Shaanxi Normal University, Xi’an 710062, P.R. China 相似文献
16.
A. Mancha de Llanos M. M. De Zan M. J. Culzoni A. Espinosa-Mansilla F. Cañada-Cañada A. Muñoz de la Peña H. C. Goicoechea 《Analytical and bioanalytical chemistry》2011,399(6):2123-2135
A liquid chromatographic method has been developed, in combination with the multivariate curve resolution-alternating least
squares algorithm (MCR-ALS), for the simultaneous determination of marker pteridines in urine samples. A central composite
design has been applied to optimize the factors influencing the separation (buffer concentration, buffer pH, flow rate, oven
temperature, mobile-phase composition). A set of 15 calibration samples were randomly prepared, in a concentration range of
0.5–10.5 ng mL−1 for neopterin, biopterin, and pterin; 4.0–8.0 ng mL−1 for xanthopterin; and 0.5–4.5 ng mL−1 for isoxanthopterin. The validation was carried out with fortified urine samples from healthy adults. The optimized conditions
were a mobile-phase composition of 10 mM citric buffer at pH 5.44 and acetonitrile (94.5/5.5, v/v), a flow rate of 1.0 mL min−1, and an oven temperature of 25 °C. The detection system consisted of a fast-scanning spectrofluorimeter, which allows obtaining
of second-order data matrices containing the fluorescence intensity as a function of retention time and emission wavelength.
In this work, MCR-ALS was used to cope with coeluting interferences, on account of the second-order advantage inherent to
this algorithm which, in addition, is able to handle data sets deviating from trilinearity, like the high-performance liquid
chromatography data analyzed in the present report. The developed approach enabled us to determine five pteridines, some of
them with overlapped profiles, reducing the experimental time and reagent consumption. Ratio values for pteridines/creatinine
in urine, for infected children with different pathologies, are reported in this work. 相似文献
17.
A simple and selective method using ammonium pyrrolidinedithiocarbamate modified activated carbon (APDC-AC) as solid phase
extractant has been developed for speciation of As(III) in water samples. At pH 1.8–3.0, As(III) could be adsorbed quantitatively
by APDC-AC, and then eluted completely with 2.0 mL of 0.1 mol L−1 HNO3, while As(V) could almost not be retained at pH 1–7. Effects of acidity, sample flow rate, concentration of elution solution
and interfering ions on the recovery of As(III) have been systematically investigated. Under the optimal conditions, the adsorption
capacity of APDC-AC for As(III) is 7.3 mg g−1. The detection limit (3σ) of As(III) is 0.05 ng mL−1 for graphite furnace atomic absorption spectrometry (GFAAS) with enrichment factor of 50, and the relative standard deviation
(RSD) is 4.1% (n = 9, C = 5 ng mL−1). The method has been applied to the determination of trace As(III) in water, and the recoveries of As(III) are 100 ± 10%.
Correspondence: Yiwei Wu, Department of Chemistry and Environmental Engineering, Hubei Normal University, Huangshi 435002,
P.R. China 相似文献
18.
A new method of direct single-drop microextraction combined with electrothermal atomic absorption spectrometry (ETAAS) is
presented for the determination of trace Cd and Pb with dithizone (H2DZ) as chelating reagent. Factors influencing the microextraction efficiency and determination, such as pH, microdrop volume,
stirring rate, extraction time were evaluated. Under the optimized experimental conditions, the detection limits of the method
are 2 and 90 pg mL−1 for Cd and Pb, and the relative standards deviations for 0.5 ng mL−1 Cd and 10 ng mL−1 Pb are 11 and 12.8%. After 10 min of extraction, the enrichment factors for Cd and Pb are 118 and 90, respectively. The results
for the determination of Cd and Pb in tap water, spring water, river water, pond water, lake water and spiked water samples
demonstrate the accuracy, recovery and applicability of the method. An environmental water certified reference material (GSBZ
50009-88) was analyzed, and the determined values are in a good agreement with the certified values.
Correspondence: Bin Hu, Department of Chemistry, Wuhan University, Wuhan 430072, P.R. China 相似文献
19.
Silica gel was prepared by the sol–gel method, modified with nanometer-sized zirconium oxide, and this material was characterized
by X-ray diffraction. A micro-column packed with silica gel modified with nanometer zirconium oxide as sorbent has been developed
for the quantitative separation and preconcentration of trace amounts of chromium(III) prior to their determination by electrothermal
atomic absorption spectrometry. Total chromium was determined after the reduction of chromium(VI) to chromium(III) by 10%
(m/v) of aqueous ascorbic acid as reducing reagent. The adsorption capacity for chromium(III) was found to be 2.36 mg g−1. The detection limit for chromium(III) was 15 ng L−1 with an enrichment factor of 100. The relative standard deviation was 3.2% (n = 7, c = 2.0 ng mL−1). 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