摘要:

AbstractThe peroxyoxalate chemiluminescence(CL) detection method for the evaluation of the CL intensity of malondialdehyde(MDA) condensates with seven 2‐thiobarbituric acid derivatives is described. The method consists of a flow injection technique together with a CL detection system using bis(2,4,6‐trichlorophenyl) oxalate(TCPO) and hydrogen peroxide as chemiluminogenic reagents. Linear correlations between CL intensity and concentration are obtained for pmol levels of condensates. Among the condensates, 1,3‐diethyl‐2‐thiobarbituric acid(DETBA)–MDA shows the largest CL intensity. High performance liquid chromatography (HPLC)/CL detection of DETBA–MDA and 1,3‐diphenyl‐2‐thiobarbituric acid(DPTBA)–MDA using a mixture of TCPO and hydrogen peroxide in acetonitrile as a postcolumn reagent solution is also described. The detection limits for DETBA–MDA and DPTBA–MDA are 20 and 200 fmol, respectively, per 20 μL injection at a signal‐to‐noise ratio of 2. This HPLC/CL detection system was applied to the defermination of MDA in rat brains by using DETBA as a fl

ISSN:0269-3879    

DOI:10.1002/bmc.1130060202

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractThe method for the simultaneous determination of angiotensin‐converting enzyme (ACE) inhibitor enalapril and its active metabolite enalaprilat in plasma and urine was developed by gas chromatography/mass spectrometry. Enalapril and enalaprilat in plasma and urine were extracted and cleaned up by using Sep‐Pak C18 and silica cartridges. Derivatization was carried out using diazomethane and trifluoroacetic anhydride. Detection by selected ion monitoring was selected tom/z288 (enalaprilat) and 302 (enalapril). The detection limit of enalapril and enalaprilat was 200 pg/mL in plasma and 2 ng/mL in urine. This method was applied to the pharmacokinetic analysis of enalapril and enalaprilat in body flu

ISSN:0269-3879    

DOI:10.1002/bmc.1130060203

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractThis paper describes a high performance liquid chromatographic (HPLC) method for determining 1,5‐anhydroglucitol in plasma, in which anion exchange chromatography and pulsed amperometric detection are used. Plasma samples deproteinized with trichloroacetic acid are passed through a three‐layer column packed with (1) strongly basic anion (BO 3−3form, the upper layer), (2) strongly basic anion (OH−form, the middle layer) and (3) strongly acidic cation (H+form, the lower layer) exchange resins. 1,5‐Anhydroglucitol is efficiently recovered in the flow‐through fraction and interfering substances are completely removed by the column treatment. The analytical response of the method is linear with concentration to 40 mg/L, and it is possible to detect as little as 0.1 mg 1,5‐anhydroglucitol per litre of plasma. Analytical recovery is between 96 and 103%, and there is good agreement between the results measured by our method and by a gas/liquid chromatographic method (r= 0.998). The method has been successfully used for the determination of very low 1,5‐anhydroglucitol concentrations (<1 mg/L) in the plasma of

ISSN:0269-3879    

DOI:10.1002/bmc.1130060204

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractAntibodies against gangliosides isolated from small tumour and nervous tissue specimens can be reliably detected in serum samples by the ganglioside electrotransfer technique without the need for previous purification steps. After separation by high performance thin layer chromatography gangliosides are transferred from silica gel plates to hydrophobic polyvinylidene difluoride membranes. These membranes are highly suitable for immuno‐staining. The use of a 15‐slit device allows simulataneous testing of up to 15 serum samples. Samples of serum from 39 patients with clear‐cell carcinoma of the kidney, mammary carcinoma, ovarian carcinoma and neurological disorder together with samples from healthy controls were tested for anti‐ganglioside antibodies from various

ISSN:0269-3879    

DOI:10.1002/bmc.1130060205

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractOn the basis of the heparin‐like effect of phosphotungstate (PTA), we have shown that it is useful for the purification of hepatitis‐B virus surface antigen (HBsAg) using heparin‐Sepharose affinity chromatography. HBsAg was eluted with 0.2–0.6 M NaCl. HBsAg was also eluted with PTA at approximately 1 mM, and the HBsAg fraction thus obtained contained fewer impurities than the corresponding fraction eluted with NaCl. Moreover, PTA yielded HBsAg and hepatitis‐B virus e‐antigen simultaneously. PTA may specifically reduce the affinity of HBsAg for heparin as well as simply competing with heparin for an anion‐binding site of HBsAg. Residual PTA in the eluate was easily decomposed by alkalization, which was useful for subse

ISSN:0269-3879    

DOI:10.1002/bmc.1130060206

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractWe have developed a novel approach for the analysis of asparagine‐linked neutral oligosaccharides derived from glycoproteins. The oligosaccharides are labelled withp‐aminobenzoic ethyl ester and the derivatives are separated on two high performance liquid chromatographic columns, one containing amide‐silica and the other containing octadecyl‐silica. The elution positions of 39 different ABEE‐oligosaccharides on the two columns were plotted on a two‐dimensional map. Unique non‐overlapping positions of these oligosaccharides demonstrate that this technology would be useful for the identification of Asn‐linked oligosaccharides at h

ISSN:0269-3879    

DOI:10.1002/bmc.1130060207

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractA universal peroxyoxalate–chemiluminescence detection system for high performance liquid chromatography, available for a variety of mobile phases, has been developed. The system consisted of a dual‐head short‐stroke pump and a chemiluminescence detector. The standard conditions using bis(2,4,6‐trichlorophenyl) oxalate (TCPO) as aryl oxalate were as follows. The first postcolumn solution was the mixture of 0.5 M imidazole–nitric acid (pH 7.5) and acetonitrile (1:4, v/v). The second was acetonitrile containing TCPO–hydrogen peroxide. These two solutions were delivered by the two pump‐heads. After the pH of the column eluate was adjusted to the optimum range (6.5–7.5) by the first postcolumn solution, the solution was mixed with the second postcolumn solution. After flowing through a reaction coil, the chemiluminescence of the mixture was monitored. Using this system, a high sensitivity (fmol level) was obtained for perylene as an analyte with mobile phases having different pH values (2.0–8.0). Polycyclic aromatic hydrocarbons became detectable to a high sensitivity even after the column separation using an acidic mobile phase. The detection sensitivity of nitrated pyrenes after on‐line electrochemical reduction using an acidic mobile phase was also increased. This system might be available for other aryl oxalates by some modifications of the p

ISSN:0269-3879    

DOI:10.1002/bmc.1130060208

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractCapillary supercritical fluid chromatographic (SFC) method has been developed for the determination of panaxadiol and panaxatriol in ginseng and its preparations. 0.1 g ginseng or an appropriate amount of its preparations was hydrolysed by 15% H2SO4in an ethanol: water (1:1 v/v) solution for 4 h followed by 15% NaOH for 0.5 h. The mixture was extracted by cyclohexane. The cyclohexane extracts were purified by a partition column and concentrated by an adsorption column and then analysed by SFC. Methyltestosterone was used as the internal standard.

ISSN:0269-3879    

DOI:10.1002/bmc.1130060209

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractThe use of capillary electrophoresis for simultaneous separation and detection of the two bipyridylium herbicides, paraquat and diquat, was investigated. Both herbicides were extracted from fortified sera with disposable ODS‐silica cartridges. Separation was carried out using a capillary tube (50 μm i.d., 750 mm) of fused silica containing 10 mM glycine–HCl buffer (pH 3.0), 40 mM NaCl and 20% methanol as the carrier. Paraquat and diquat were completely separated in 10 min at an applied potential of 20 kV. On‐column UV monitoring allowed detection of both herbicides simultaneously. The assay sensitivity was 0.05 μg/mL (signal‐to‐noise ratio, 2:1), which probably increases with increase in the sample volume of serum. Analytical recovery of both herbicides added to serum was about 97% at concentrations of 0.

ISSN:0269-3879    

DOI:10.1002/bmc.1130060210

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractPolysulphone (PS) was chemically modified by acrylation–amination and by chloromethylation‐amination, respectively. An ultrafiltration membrane of chemically modified polysulphone (CMPS) was prepared by the phase inversion method. Trypsin was then covalently bonded onto the CMPS membrane by diazotization. The activity of immobilized trypsin reaches up to 10200 U/g; 15 mg trypsin was immobilized on 1 g CMPS membrane. Separation of soybean trypsin inhibitor was carried out on the affinity membrane, yielding 6.5 mg pure trypsin inhibitor in one run. The enzyme membrane has good activity and stabil

ISSN:0269-3879    

DOI:10.1002/bmc.1130060211

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY