共查询到20条相似文献,搜索用时 15 毫秒
1.
Separation of organic and inorganic arsenic species by capillary zone electrophoresis 总被引:1,自引:0,他引:1
Summary Capillary zone electrophoresis has been used to separate arsenite, arsenate, dimethylarsinic acid, and phenyl-,p-aminophenyl-, ando-aminophenylarsinic acids. Identification and quantification of the arsenic species at mg L−1 levels was possible by use of direct UV detection at 200 nm. The relative standard deviation (n=7) ranged from 0.97 to 1.52% for migration times and from 2.08 to 4.31% for peak areas. A method for rapid separation of
inorganic arsenic species was also developed; by use of this method arsenite and arsenate could be separated within 2 min.
Presented at Balaton Symposium on High-Performance Separation Methods, Siófok, Hungary, September 1–3, 1999 相似文献
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高效毛细管区带电泳法快速测定尿液中的肌酐 总被引:1,自引:0,他引:1
建立了一种快速测定尿中肌酐浓度的高效毛细管电泳方法。利用非涂层石英毛细管(64.5 cm×50μm i.d),以pH 2.5,0.1 mmol/L H3PO4作为电泳缓冲液,检测波长191 nm,用0.05 Pa压力进样4 s,在电压16 kV快速分离尿液中的肌酐,采用外标法定量。肌酐的迁移时间约为5.5 min,肌酐浓度在34.5~8840μmol/L范围内呈良好的线性(r2=0.999)。平均日内精密度为2.5%,日间精密度为3.0%。回收率94.1%~99.0%。与全自动生化分析仪碱性苦味酸速率法相比有良好的相关性(r=0.990,n=56)。高效毛细管电泳法测定尿肌酐可应用于临床样品的检测。 相似文献
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Summary A novel method of separating and detecting trace aluminum by capillary zone electrophoresis is described. Aluminum is reacted with lumogallion [4-chloro-3-(2,4-dihydroxyphenylazo)-2-hydroxybenzen-1-sulphonic acid] so that the complex can be selectively and sensitively detected by a laser-induced fluorescence detector after capillary electrophoretic separation. Using the proposed method, limits of detection in the sub parts per billion range are achieved. The technique is applied to the determination of aluminum in human serum. 相似文献
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A method of quickly determining ascorbic acid and sorbic acid by capillary zone electrophoresis with ultraviolet detection was developed. The choice of background electrolyte, wavelength, injection time and applied voltage were discussed. Ascorbic acid and sorbic acid were well separated in 80 mmol L−1 boric acid-5 mmol L−1borax (pH = 8.0) in 5 min at the detecting wavelength of 270 nm. Under the optimum condition, the method has linear ranges of 2.54-352.00 mg L−1 for ascorbic acid and 1.08-336.39 mg L−1 for sorbic acid with the detection limit of 1.70 mg L−1 for ascorbic acid and 0.54 mg L−1 for sorbic acid, respectively. Other organic acids in fruit juices have no effect on the detection. This method is very feasible and simple and can be used to detect ascorbic acid and sorbic acid in fruit juices. 相似文献
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Separation of flavonoids and phenolic acids from propolis by capillary zone electrophoresis 总被引:3,自引:0,他引:3
Volpi N 《Electrophoresis》2004,25(12):1872-1878
The simultaneous determination of twelve different flavonoids, pinocembrin, acacetin, chrysin, rutin, catechin, naringenin, galangin, luteolin, kaempferol, apigenin, myricetin, and quercetin, two phenolic acids, cinnamic acid and caffeic acid, and one stilbene derivative, resveratrol, in propolis extracts used in medicine has been investigated by capillary zone electrophoresis (CZE). With a buffer constituted by sodium tetraborate 30 mM, pH 9.0, and 15 kV applied voltage, the 15 polyphenols were separated on an uncoated fused-silica capillary within 40 min using normal polarity. Under the experimental conditions used, a linear relationship was calculated between the CZE migration times and the molecular weight of polyphenols' expression of the increasing amount of their hydroxyl groups and polarity. Regression equations revealed a linear relationship (correlation coefficients > 0.97) between the peak area of each polyphenol species and their concentration, from 6 to 120 ng. The levels of analytes in three different propolis extracts, ethanolic, aqueous-ethanolic and aqueous-glycolic, used to prepare various commercial medicinal products, were determined. The aqueous-ethanolic propolis extract showed a great percentage of caffeic acid, galangin, quercetin, and chrysin, whilst the ethanolic preparation was composed of a great amount of resveratrol, chrysin, and caffeic acid. On the contrary, the aqueous-glycolic propolis preparation was composed of approx. 11% of caffeic acid and a low amount of the other identified flavonoids due to the presence of approx. 85% of nonidentified compounds. CZE represents a valuable method for the qualitative and quantitative assay of the most relevant polyphenol components of propolis, representing an alternative to obtain typical fingerprints of propolis and a reliable identification of a large number of propolis polyphenolic species. 相似文献
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Summary A capillary zone electrophoresis method is proposed for the separation of five antidepressants. Optimum conditions for the
separation were investigated. A background electrolyte solution consisting of 40 mM phosphate buffer adjusted to pH 2.5, hydrodynamic
injection, and a 28 kV separation voltage were used. Relative standard deviations (RSD) were <0.9% and <1.7% for migration
time and corrected peak area (n=21), respectively. The detection limits for the five antidepressants ranged from 0.3 to 0.7 mg L−1. The stability of the solutions, linearity, accuracy, and precision were examined during validation of the method. The method
is rapid and sensitive, when it was tested for the analysis of pharmaceutical formulations the recoveries obtained were between
98 and 103% of the nominal content. 相似文献
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Summary A capillary zone electrophoresis method for identification and determination of aesculin and aesculetin has been established
using borate-phosphate buffer containing 30% ethanol with on-column UV detection. A detailed investigation of the influence
of changes in borate concentration, pH, applied voltage, temperature and organic modifier was then carried out. For both aesculin
and aesculetin, a linear plot of migration time (MT) against borate concentration was obtained, and ln[measured peak area
(MA)] and lnMT both gave linear plots against ln(applied voltage) with correlation coefficient r>0.999, which also resulted
in a linear correlation between MA and MT (r≥0.9998) under varied voltage. Ethanol as organic modifier to the background electrolytes
helped in separating aesculin and aesculetin from other components in ash barks. The reproducibility with relative standard
deviation in MT and in normalized peak area(NA) and linearity based on NA against concentration were evaluated. Finally, the
method was successfully applied to monitor the quality of different ash barks and to compare the effect of sample preparation
on content of bioactive components in ash bark. Results indicate that CZE promises to be applicable to quality control of
traditional Chinese medicines containing aesculin and aesculetin. 相似文献
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Separation and determination of coumarins from Cacalia tangutica by capillary zone electrophoresis 总被引:2,自引:0,他引:2
Capillary zone electrophoresis (CZE), using a 20 mmol/L borate buffer at pH 10.5, was developed for the identification and determination of three coumarins--7-hydroxy-coumarin (HC), 7-hydroxy-8-methoxy-coumarin (HMC) and 7-O-beta-D-glucosyl-coumarin (GC)--in the extracts of the flower of Cacalia tangutica. Regression equations revealed linear relationships (correlation coefficient 0.9986-0.9990) between the corrected peak area (the ratio of peak area to migration time) of each constituent and its concentration. The relative standard deviations (RSD) of the migration time and peak area were 1.45-1.52 and 2.60-3.84% (intra-day), and 1.75-2.22 and 2.90-4.04% (inter-day), respectively. The recoveries of three constituents ranged between 94.5 and 105.6%. The effects of pH value, buffer concentration and applied voltage on the migration behavior of HC, HMC and GC were investigated. The contents of the three active constituents in the flower of Cacalia tangutica were successfully determined within 6 min under the optimum conditions chosen. Moreover, the dissociation constants for three coumarins were also determined by CE. 相似文献
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Hiroyuki Nishi 《Journal of separation science》1995,18(10):659-664
The capillary electrophoretic (CE) separation of the enantiomers of three binaphthyl compounds is investigated. Several CE modes such as cyclodextrin (CD) modified capillary zone electrophoresis (CZE) (CD-CZE), micellar electrokinetic chromatography (MEKC), cyclodextrin electrokinetic chromatography (CD-EKC), etc. are employed for the simultaneous enantiomer separation of the three solutes. The successful separation was achieved by combining two modes, in other words by using more than two chiral selectors. A development of the CE enantiomer separation is demonstrated for the binaphthyl compounds. The enantioselectivity of binaphthyl compounds is alo briefly discussed. 相似文献
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A simple capillary zone electrophoresis (CZE) method has been developed for analyzing seven nonsteroidal anti-inflammatory drugs (NSAIDs)—sulindac (SU), ketoprofen (KE), indomethacin (IN), piroxicam (PI), nimesulide (NI), ibuprofen (IB), and naproxen (NA). The separation was run using borate buffer (60 mmol L–1, pH 8.5) containing 13% (v/v) methanol at 20 kV, and detected at 200 nm. Several conditions were studied, including concentration and pH of borate buffer, methanol percentage, and separation voltage. In method validation, the calibration plots were linear over the range 40.0–500.0 mol L–1. In intra-day and inter-day analysis, relative standard deviations (RSD) and relative errors (RE) were all less than 5%. The limits of detection were 10 mol L–1 for SU, IN, PI, and 20 mol L–1 for KE, NI, IB, NA (S/N = 3, sampling 6 s by pressure). All recoveries were greater than 95%. This method was applied to the quality control of six NSAIDs in pharmaceuticals using NI as internal standard (IS). The assay results were within the labeled amount required by USP 25. 相似文献
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Balthasar Jung Jitka Caslavska Wolfgang Thormann 《Journal of separation science》2009,32(20):3497-3506
Ethyl glucuronide (EtG) is a marker of recent alcohol consumption. For the optimization of the analysis of EtG by CZE with indirect absorbance detection, the use of capillaries with permanent and dynamic wall coatings, the composition of the BGE, and various sample preparation procedures, including dilution with water, ultrafiltration, protein precipitation, and SPE, were investigated. Two validated screening assays for the determination of EtG in human serum, a CZE‐based approach and an enzyme immunoassay (EIA), are described. The CZE assay uses a coated capillary, 2,4‐dimethylglutaric acid as an internal standard, and a pH 4.65 BGE comprising 9 mM nicotinic acid, ε‐aminocaproic acid and 10% v/v ACN. Proteins are removed via precipitation with ACN prior to analysis and the LOQ is 0.50 mg/L. The EIA is based upon commercial reagents which are promoted for the determination of urinary EtG. Krebs–Ringer solution containing 5% BSA is used as a calibration matrix. All samples are ultrafiltered prior to analysis of the ultrafiltrate on a Mira Plus analyzer. Assay calibration ranged between 0 and 2 mg/L and the upper reference limit was determined to be 0.05 mg/L. Both assays proved to be suitable for the analysis of samples from different individuals. For EtG levels above 0.50 mg/L, good agreement was observed for the comparison of the results of the two methods. 相似文献
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A sensitive method based on quantum dot (QD)-enhanced capillary electrophoresis-chemiluminescence (CE-CL) detection was developed for simultaneous determination of dopamine (DA) and epinephrine (E). In this work, CdTe QD was added into the running buffer of CE to catalyze the post-column CL reaction between luminol and hydrogen peroxide, achieving higher CL emission. Negative peaks were produced due to the inhibitory effects on CL emission from DA and E eluted from the electrophoretic capillary. The decrease in CL intensity was proportional to the concentration of DA and E in the range of 8.0 × 10−8-5.0 × 10−6 M and 4.0 × 10−8-5.0 × 10−6 M, respectively. Detection limits for DA and E were 2.3 × 10−8 M and 9.3 × 10−9 M, respectively. Using this method, the levels of DA and E in human urine from healthy donors were determined. 相似文献
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Simultaneous determination of flavonoids in chrysanthemum by capillary zone electrophoresis with running buffer modifiers 总被引:1,自引:0,他引:1
Despite the separation efficiency of capillary electrophoresis (CE) is much higher than other chromatographic methods, it is sometimes difficult to perfectly separate the complex ingredients in biological samples. One possible and simple way to develop the separation effect in CE is to add some modifiers in the running buffer. In this paper, the suitable running buffer modifiers were explored to simultaneously separate and detect six typical flavonoids (apigenin, luteolin, kaempferol, quercetin, (+)-catechin and (−)-epicatechin) which are the main active ingredients in chrysanthemum by capillary zone electrophoresis with amperometric detection (CZE-AD). It was found that when β-cyclodextrin (β-CD) and the mixture of methanol and ethanol were used as running buffer modifiers, a baseline separation of the six analytes could be accomplished in less than 20 min and the detection limits were as low as 10−7 or 10−8 g ml−1. Other factors affecting the CZE separation, such as working potential, pH value and ionic strength of running buffer, separation voltage and sample injection time were extensively investigated. Under the optimum conditions, a successful practical application on the determination of chrysanthemum samples confirmed the validity and practicability of this method. 相似文献