摘要:

An automated procedure for the determination of Fructose 2,6-bisphosphate (Fru 2,6-P2) is described. The method based on the degree of activation of the enzyme Pyrophosphate: D-fructose 6-phosphate 1-phosphotransferase from potato tuber by Fru 2,6-P2, uses a discrete-sample automatic analyzer to perform the procedure and to monitor the spectrophotometric changes. The detection limit of Fru 2,6-P2levels is 0.016 pmol (6.25 × 10−14mol ml−1). The coefficients of variation observed when assaying 0.5 nM of Fru 2,6-P2in the reaction mixture, 1.34% and 7.39% (n=10) for the automated and manual method are significantly different. Thus a 5-fold higher precision is shown by the automatic method. The same precision is observed when assaying biological samples from starved or refed animals.

ISSN:0003-2719    

DOI:10.1080/00032719508000014

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Suitability of the DNA content in urine stained material was evaluated for use in forensic analysis. High molecular weight (HMW) DNA (>20 kb, where 1kb equals 1000 base pairs) was obtained in only 9% (4 out of 44) of laboratory produced urine stains using an organic extraction method. Slot blot hybridization analysis with a human specific repeat probe (SLI332) showed that these stains contained DNA of human origin. A group of 12 urine stains from the original 44 that did not yield any DNA was subjected to Chelex resin extraction followed by PCR amplification for genotyping of the Human Leucocyte Antigen (HLA) DQA1 locus. Typing was successfull on 5 of the 12 samples. The concentrated sediment from the original liquid urine portion of the samples was similarly subjected to Chelex extraction and HLA DQA1 typing. Six out of ten samples were successfully typed. Blood specimens collected from the urine donors to serve as typing controls yielded identical genotypes in all cases. PCR based analysis of urine stains may yield useful forensic information even when the DNA content is extremely low, degraded or undetectable.

ISSN:0003-2719    

DOI:10.1080/00032719508000015

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

A method for the determination of beryllium in urine samples by Graphite Furnace Atomic Absorption Spectrophotometry (GFAAS) has been developed. The background correction problem due to the sample matrix was overcome by solvent extraction step. Urine samples were digested with a mixture of concentrated nitric and sulphuric acids. Beryllium in solution was complexed with acetylacetone, extracted in chloroform at pH 8.5 and back extracted in 2%(v/v) nitric acid for final analysis by AAS. The range of concentrations of beryllium observed in urine samples covering both occupational and control subject was 0.03–0.37 ng Be/ml.

ISSN:0003-2719    

DOI:10.1080/00032719508000016

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

A method has been designed for the quantification of 2-oxoglutarate after ion-exclusion high performance liquid chromatography of samples containing high levels of citrate plus isocitrate, which interfere in the quantification of 2-oxoglutarate. The amount of 2-oxoglutarate in a mixed chromatographic peak containing citrate plus isocitrate has been estimated using a diode array detector and calculating the extinction coefficient of these molecules at three wavelengths. The reliability of the method has been ascertained using mixtures of standard organic acids. This procedure has been applied to determine the intracellular content of 2-oxoglutarate in the cyanobacteriumPhormidium laminosum.

ISSN:0003-2719    

DOI:10.1080/00032719508000017

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Pulsed field gel electrophoresis runs were performed in small Contour Clamped Homogeneous Electric Field (miniCHEF) and Transverse Alternating Electric Field (miniTAFE) chambers. Minichambers use minigels and they could be suitable for analytical and preparative purposes. In minichambers higher electric fields and equal heat evolution were achieved with the same voltage applied to conventional chambers. Nine to tenSaccharomyces cerevisiaechromosomes were resolved in minichambers applying 13–14 V/cm and 50 s of pulse time during 3.2 - 5 h. It was found a linear relationship between the migration per pulse and the electric field (at constant pulse time). An equation relating the pulse time and the electric fields was attained. It was used to obtain isopatterns at several electric fields despite the chamber dimensions. Miniapparati use simple power supplies and cooling systems and save samples, reagents, laboratory bench space and time.

ISSN:0003-2719    

DOI:10.1080/00032719508000018

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

A direct electroanalytical method for the determination of estrogens is proposed, and a carbon paste electrode modified with oleic acid for the electrochemical oxidation of estrogens is described. A sensitive and reproducible peak is obtained by comparison with voltammetric responses at different modified electrodes (CPA, CPOSaand CPOPa). The experimental parameters and electrochemical properties of estrogens at the modified electrodes are discussed. Its oxidation current depends on the electrolyte species and the alcohol content. The carbon paste electrodes modified with oleic acid have been developed for the assay of estriol in pharmaceutical samples. A detection limit 4 × 10−7mol/l of estradiol is estimated under selected conditions by using the 1.5th order differential stripping analysis.

ISSN:0003-2719    

DOI:10.1080/00032719508000019

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

A number of metal-furazolidone complexes have been synthesized and screened for antibacterial and antifungal activity. The study reveals the remarkable efficacy of Co(II), Cu(II), Zn(II) and Cd(II) complexes against the various strains of bacteria and fungi, viz.,Pseudomonas mangiferae, Bacillus pumillus, andSalmonella typhisuggest a strong possibility of its application for the treatment of fungal skin infections. The most striking feature has been the activity of Cu-furazolidone complex, it was found to be uniformly active against all the strains of bacteria and fungi under study. Electroanalytical findings of these metal furazolidone complexes have also been performed.

ISSN:0003-2719    

DOI:10.1080/00032719508000020

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

An assay of atenolol in human serum is described using a 3 μm silica column with a 60:40 v/v 6.25 mM sodium dihydrogen phosphate pH 3.0-acetonitrile mobile phase at 1 mL/min; the ultraviolet detector was set at 254 nm. Minimum detectability of the drug was estimated to be 20 ng/mL (S/N = 2). The method is linear in the 100–1000 ng/mL range (r = 0.9992, n = 9). An ethylsilane solid phase extraction column was used for sample cleanup and recovery of atenolol from serum was 103 ± 4% (n = 3). Retention times for atenolol and metoprolol (internal standard) were 6.6 and 7.5 min, respectively, and typical theoretical plates were 17,583 and 22,680, respectively. Resolution between internal standard and atenolol peaks was calculated to be 4.5. A typical analysis was completed in less than 45 min. The good sensitivity and reproducibility of the method should render it useful for the assay of atenolol levels in serum.

ISSN:0003-2719    

DOI:10.1080/00032719508000021

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Two different types of solid-state coatings based on the phosphorescent metalloporphyrins - polymer film compositions or Langmuir-Blodgett films - were studied comparatively with respect to their application to sensing of SO2. While the polymer films were only slightly sensitive to SO2, LB-coatings appeared to be highly suitable for analyzing SO2in air in the range 0.01 - 2 % (v/v). Performance characteristics of the new phosphorescence lifetime-based sensor for SO2were studied. Interferences by a number important species on sensing of SO2in gas phase were studied.

ISSN:0003-2719    

DOI:10.1080/00032719508000022

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Compared with β-Cyclodextrin (β-CD), 2-O-[(R)-2-hydroxypropyl]-β-CD (A) is more sensitive for chiral recognition. When (A) was used as the chiral mobile phase additive, some racemic amino acids were directly separated on silica gel TLC for the first time.

ISSN:0003-2719    

DOI:10.1080/00032719508000023

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor