bluuebunny/crossref_metadata_2025_split huggingface dataset:
Use of high performance liquid chromatography in defining the abnormalities in the free amino acid patterns in the cerebrospinal fluid of patients with aseptic meningitis
Authors: Halawa Imad , Baig Shahid , Qureshi G. Ali 
Published: May 2005

AbstractFree amino acids were quantitatively determined in crebrospinal fluid (CSF) and plasma samples from patients with aseptic meningitis by a newly developed high performance liquid chromatographic (HPLC) method. The method of analysis was based on precolumn derivatization of orthophthalaldehyde in the presence of 2‐mercaptoethanol and detection was made at Eex = 340 nm and Eem = 450 nm. The method was sensitive and the limit for detection was < 1 pmol for most of the amino acids. It took 45 min to separate 26 amino acids with highly reproducible results, giving a coefficient of variance for retention times and integrated areas < 0.4% and 2%, respectively, after five replicate runs. The results accumulated in 10 patients were compared statistically with 11 age‐matched healthy controls. Among the amino acids almost all the neurotransmitter candidates, such as aspartic acid, glutamic acid, glutamine, glycine, tyrosine, phenylalanine and γ‐aminobutyric acid (GABA), were significantly increased in the patients' CSF, whereas arginine and threonine were low. No change was observed in plasma amino acids in patients as compared to healthy controls. The higher levels of most of the neurotransmitters, especially GABA, aspartic acid and glutamic acid, could be used diagnostically in assessing the progression and remission in aseptic meningitis.
Automated quantitative microcolumn chromatography of haemoglobin A2
Authors: Ersser R. S. , Blight Leonie , Hjelm N. M. , Chambers K. , James D. 
Published: May 2005

AbstractAutomated cation exchange microcolumn chromatography of haemoglobins has been modified for the analysis of haemoglobin A2. It provides the quantitative data of sufficient precision and specificity for the investigation of potential heterozygotes for β‐thalassaemia. Results have been compared with an established method of electrophoresis followed by densitometry of the eluted bands.
Liver high performance liquid chromatographic porphyrin profiles in experimental porphyria induced by peroxidizing herbicides
Authors: Krijt J. , Sanitrák J. , Vokurka M. , Janoušek V. 
Published: May 2005

AbstractThe effect of peroxidizing herbicides on the liver porphyrin content of experimental animals was examined. Mice treated with the herbicide oxadiazon accumulated uroporphyrin and protoporphyrin in the liver. Fomesafen‐treated mice accumulated uroporphyrin and heptacarboxylic porphyrin.
Study of the solid phase extraction of pentoxifylline and its major metabolite as a basis of their rapid low concentration gas chromatographic determination in serum
Authors: Marko Vladimír , Bauerová Katarína 
Published: May 2005

AbstractA gas—liquid chromatographic method for the determination of pentoxifylline and its secondary alcohol metabolite in serum has been developed. The method is based on the combination of solid phase extraction, capillary column separation and nitrogen—phosphorus detection of the analytes. Optimization of the solid phase extraction conditions permitted a low concentration determination, with limits of determination of 2 n/mL and 10 n/mL for pentoxifylline and its metabolite, respectively. The simplicity and rapidity of the extraction step was preserved.
Determination of 10α‐methoxy‐9,10‐dihydrolysergol, a nicergoline metabolite, in human urine by high performance liquid chromatography
Authors: Sioufi A. , Sandrenan N. , Godbillon J. 
Published: May 2005

AbstractA specific method for the determination of 10α‐methoxy‐9,10‐dihydrolysergol, a nicergoline metabolite (metabolite 2), in urine is described. Metabolite 2 was well separated from the urine components on a reversed phase column, Hypersil ODS 5 μm, using an acetonitrile: pH 3.5 phosphate buffer (40:60, v/v) as the mobile phase at a flow rate of 1 mL/min. UV detection was set up at 220 nm. After addition of a known amount of lysergamide as the internal standard, the compounds were extracted from alkalysed urine on a pre‐packed glass column (Extrelut 1) with dichloromethane. With 0.5 mL urine, concentrations down to 0.56 μmol/L could be determined.
Phosphotungstate as a useful eluent for hepatitis‐B virus surface antigen purification by heparin‐sepharose affinity chromatography
Authors: Tajima Yutaka , Nagumo Fumio , Nishimura Tadataka , Tadano Jutaro 
Published: May 2005

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 subsequent studies.
The combination of normal phase with reversed phase high performance liquid chromatography for the analysis of asparagine‐linked neutral oligosaccharides labelled with p‐aminobenzoic ethyl ester
Authors: Matsuura Fumito , Ohta Masaya , Murakami Koichi , Hirano Kaoru , Sweeley Charles C. 
Published: May 2005

AbstractWe have developed a novel approach for the analysis of asparagine‐linked neutral oligosaccharides derived from glycoproteins. The oligosaccharides are labelled with p‐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 high sensitivity.
Membrane affinity chromatography used for the separation of trypsin inhibitor
Authors: Guo Wei , Shang Zhenhua , Yu Yinian , Guan Yafeng , Zhou Liangmo 
Published: May 2005

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 stability.
TLC separation of certain tetracycline and amino glycopeptide antibiotics
Authors: Bhushan R. , Ali Imran 
Published: May 2005

AbstractThe separation of tetracycline and amino glycopeptide antibiotics was achieved on silica gel thin layers. Tetracycline antibiotics were resolved on a Co+2 (1.0%) impregnated silica gel layer using ethanol:acetic acid: water (10:6:6, v/v/v) as the mobile phase. Amino glycopeptide antibiotics were separated on an untreated silica gel layer using the mobile phase n‐butanol: formic acid: water (6:5:7, v/v/v). The spots of these antibiotics were located by exposing the chromatoplate to iodine vapours.
An improved method for isolation and identification of Zn‐metallothionein from cadmium‐induced rat liver
Authors: Pan Aihua , Tie Feng , Ru Binggen , Li Lingyuan , Shen Tong 
Published: May 2005

AbstractZn‐metallothioneins (MT‐1 and MT‐2) were isolated and purified from Wistar rat liver induced by subcutaneous injection with cadmium chloride over a short time. Instead of Sephadex G‐50 and DEAE Sephadex A‐50, new chromatographic media produced by Pharmacia, Sephacryl S‐200, S‐100 and DEAE Sepharose Fast Flow were used in the purification of metallothioneins. The time required for purification with the new method was only 1/3 that required with the usual method and had the same purification effect and rate of recovery. The number of mercapto groups measured with modified Ellman's reagent and cysteine as standard is 20 in MT molecules. Zn and Cd concentrations in each fraction were measured by single sweep polarography rather than atomic absorption spectrophotometry. MT‐1 and MT‐2 contained 6 gram atoms of zinc, but no cadmium. Purified MT‐1 and MT‐2 were shown by high performance liquid chromatographic analysis to be highly homogeneous and had an amino acid composition similar to that of Cd‐MT.
A simple method for the quantification of famotidine in human plasma and urine by paired‐ion high performance liquid chromatography
Authors: Imai Yasuhiko , Kobayashi Shin‐Ichiro 
Published: May 2005

AbstractA new method for the quantification of famotidine consists of a simple extraction procedure and paired‐ion high performance liquid chromatography with ultraviolet detection. The method has good accuracy and precision and should be suitable for the routine measurement of plasma and urine samples for clinical studies.
Analysis of chlortetracycline by high performance liquid chromatography with postcolumn alkaline‐induced fluorescence detection
Authors: Bryan Peter D. , Hawkins Kristina R. , Stewart James T. , Capomacchia Anthony C. 
Published: May 2005

AbstractA high performance liquid chromatographic method for the analysis of chlortetracycline (CTC) using postcolumn fluorescence detection has been developed. After chromatographic separation of CTC on a polystyrenedivinylbenzene copolymer column, a highly fluorescent derivative isochlortetracycline (iso‐CTC) was formed postcolumn in an on‐line reaction coil with the addition of 25% NaOH (w/v). Chromatographic separation was achieved on a PRP‐1 column, 15 cm × 4.6 mm, with 27:73 acetonitrile:0.2% perchloric acid (v/v), at 1.0 mL/min. Fluorescence derivatization was achieved by the on‐line addition of 25% NaOH (w/v), at a flow rate of 0.2 mL/min, into the column eluant in a post‐column reaction coil. The reaction coil was 9 m of teflon (1/16 in o.d., 0.3 mm i.d.) knitted into a six‐sided coil. The fluorescent derivative was detected at λex 355 nm and λem >389 nm. Using this method after a simple sample cleanup, CTC can be detected in milk at 0.04 μg/mL, which is comparable to that obtained by microbiological assays. The detection method was linear between 0.02 μg/mL and 4 μg/mL. Because of the chromatographic separation, the method is more selective than microbiological assays and more sensitive than ultraviolet detection. With the chromatographic system described, the keto tautomeric forms of CTC and 4‐epi‐CTC are separated in a system which minimizes their formation on‐column. In acidic aqueous organic solutions, the keto tautomer of CTC is the only product formed to any significant amount.
Drug monitoring of clomipramine and desmethylclomipramine in depressed patients using a new liquid chromatographic assay
Authors: Diquet Bertrand , Thomaré Patrick , Bocquentin Muriel , Diviné Catherine 
Published: May 2005

AbstractA method has been developed for the quantitative analysis of clomipramine and its major metabolite desmethylclomipramine in plasma, using normal phase chromatography with UV detection at 254 nm. This rapid (6 min) and highly sensitive methodology (detection limits 0.5 ng/mL and 2 ng/mL for clomipramine and desmethylclomipramine, respectively; S/N = 3, 0.001 aufs) allows pharmacokinetic studies and drug monitoring of the two compounds. Using the described methodology we report an application which involved 10 depressed inpatients.
A high performance liquid chromatographic method for the determination of febantel and its major metabolites in lamb plasma
Authors: Landuyt J. , Debackere M. , Delbeke F. , McKellar Q. 
Published: May 2005

AbstractA high performance liquid chromatographic (HPLC) method for the determination of the anthelminthic pro‐benzimidazole febantel and its major metabolites in lamb plasma has been developed. Samples were extracted after addition of albendazole as internal standard, NH4OH and distilled diethyl ether. The extracted phase was dried under a stream of nitrogen redissolved in methanol and chromatographed by HPLC. Detection was by UV absorbance at 292 nm. Recovery from the plasma was 97.2, 97.1, 54.5 and 88.0% for febantel, fenbendazole, oxfendazole and oxfendazole sulphone respectively, and within‐day and between‐day coefficients of variation were 4.03, 4.69, 3.57 and 5.06% and 4.25, 3.73, 5.12 and 4.12%, respectively, for febantel, fenbendazole, oxfendazole and oxfendazole sulphone. The specificity and sensitivity of this method (limit of detection in plasma 0.025 μg/mL and ⩽0.0125 μg/mL for febantel and its metabolites, respectively) were sufficiently high to enable us to characterize the time course of the drug in the plasma after oral administration of therapeutic doses to sheep.
Rapid liquid chromatographic assay of glutathione in cultured cells
Authors: Leroy Pierre , Nicolas Alain , Thioudellet Christine , Oster Thierry , Wellman Maria , Siest Gérard 
Published: May 2005

AbstractA rapid, sensitive and selective method for the assay of glutathione in cultured cells has been developed using ion‐pair reversed phase rapid high performance liquid chromatography. The use of a 4 μm particle, 5 cm long column (Superspher 100 RP 18 end‐capped) allowed complete analysis of glutathione within 3 min. A postcolumn derivatization reaction with o‐phthaladehyde and fluorometric detection made the assay fully selective with regard to other endogenous thiols and sensitive (the detection limit was 0.5 ng of glutathione injected). The linearity range was between 0.1 and 2.0 μg/mL with good repeatability (relative standard deviation less than 5% for the lowest concentration quantitated). Recoveries of GSH from cultured cell samples were above 98%. The rapid analysis enabled the processing of a large number of samples in a short time (up to 20 per hour). The method was applied to the measurement of the intracellular glutathione amount in V79 fibroblasts along cell growth in culture.
Purification and characterization of hedgehog liver metallothioneins
Authors: Pan Aihua , Tie Feng , Duan Zhenwen , Ma Hongbao , Li Liangyuan , Ru Binggen 
Published: May 2005

AbstractTwo forms of liver metallothioneins (MTs) were purified from hedgehog exposed to zinc, using gel filtration on Sephacryl S‐100 and DEAE Sepharose Fast Flow chromatography. The peptide chain weight of both MT‐1 and MT‐2 was found to be about 10,000, as determined by high performance liquid chromatography. This value was higher than that calculated from amino acid analysis. The amino acid composition of hedgehog liver MT‐1 and MT‐2 resembles that of liver to MTs from rabbit and other species. Their distinctive features include an extremely high cysteine content, about 33% of all the amino acid residues, and an absence of aromatic amino acids and histidine. In addition, a rapid method for the determination of MTs during animal tissue purification has been established. The samples were directly added in an ammoniacal solution of a Co(II) salt for recording linear sweep polarograms. By comparison with the commonly used metal determination method, our method is direct, rapid, credible and suitable for all the MTs or MT‐like samples.
Micropreparative ion exchange high performance liquid chromatography: Applications to microsequence analysis
Authors: Nice E. C. , Fabri L. , Hammacher A. , Andersson K. , Hellman U. 
Published: May 2005

AbstractData on the characterization of anion and cation micropreparative (50X1.6 mm i.d.) HPLC columns is presented. It is shown how subnanomole quantities of protein can be efficiently recovered from such columns, rendering them compatible for use in multidimensional chromatographic strategies for the purification of trace biological samples. By selection of appropriate solvent systems (e.g., buffer‐free sodium chloride solutions), the small eluant peak volumes can be loaded directly onto the gas phase sequencer, and N‐terminal sequence data obtained. The potential of the technique is illustrated for the purification of a GTPase activating protein (GAP‐3).
High performance liquid chromatographic analyses of compounds related to nucleic acids by 3‐(1‐naphthoylamino)‐ and 3‐(1‐anthroylamino)‐propyl‐modified silica gel packing materials
Authors: Akiyama Shuzo , Nakashima Kenichiro , Yamada Kyoko , Kuroda Naotaka 
Published: May 2005

AbstractThe development of column packing materials was tried as a contribution to studies related to the further modification of 3‐aminopropyl‐modified silica gel. Consequently, we prepared two types of gel, 3‐(1‐naphthoylamino)‐ and 3‐(1‐anthroylamino)‐propyl‐modified silica gels (NAPS and AAPS). Since NAPS and AAPS, each having an aromatic ring, were expected to behave in a separation mode by a π‐π or hydrophobic interaction, their application to the analyses of the compounds related to nucleic acids was carried out. Adenosine nucleotides were consequently separated by the gels in a single analysis by a single buffer elution with UV detection. NAPS could be also successfully used for the measurement of ATPase activity in fish meat (Sillago japonica). The mobile phase consistently used in the analysis was an aqueous phosphate buffer.
High performance liquid chromatography of penicillins with penicillin‐enhanced luminol chemiluminescence detection
Authors: Nakashima Kenichiro , Kawaguchi Shinki , Akiyama Shuzo , Schulman Stephen G. 
Published: May 2005

AbstractA high performance liquid chromatographic method with chemiluminescence detection for the determination of penicillin G and ampicillin is reported. The method is based on the enhancement of the luminol chemiluminescence with β‐lactam antibiotics. The linear relationship was obtained between the peak height and the concentration of penicillin G or ampicillin up to 15 nmol per 20 μL injection. Detection limits were 1 nmol for penicillin G and 0.5 nmol for ampicillin with a signal‐to‐noise ratio of 2. Relative standard deviations for five replicate measurements of 4 nmol/injection each of penicillin G and ampicillin were 2.1 and 2.3%, respectively.
A rapid and sensitive determination of salmon calcitonin in solutions containing bovine serum albumin or gelatin
Authors: Fukuda Terumi , Yun Arifuku , Imai Kazuhiro 
Published: May 2005

AbstractA sensitive and selective reversed phase high performance liquid chromatographic method was introduced for the determination of salmon calcitonin (sCT) in solutions containing bovine serum albumin or gelatin. The method was based on the sensitive fluorescence detection of sCT by postcolumn derivatization with o‐phthal(di)aldehyde. The sample was loaded onto a reversed phase column, purified by column switching and separated with linear gradient elution using the ion pair technique. A linear relationship was obtained between the peak height and the amount injected in the concentration range 1–40 ng. The detection limit was 10 ng/mL (S/N = 3) at a sample injection volume of 100 μL.
Resolution of enantiomers of amino acids by HPLC
Authors: Bhushan R. , Joshi Shalini 
Published: May 2005

AbstractApplication of HPLC as a prime tool in the area of enantiomeric resolution has opened doors of success and varied interest. Use of chiral reagents either indirectly (as derivatization reagent) or directly (added to stationary or mobile phase) has led to achieve resolution of a wide range of compounds. Amino acids, being important molecules with simple structure and easy availability, have been extensively studied. A bibliographic survey on HPLC resolution of amino acids and derivatives along with a brief discussion on general methods of enantiomeric separation has been presented.
Quantitation and identification of two cholecystokinin peptides, CCK‐4 and CCK‐8s, in rat brain by HPLC and fast atom bombardment mass spectrometry
Authors: Qureshi G. Ali , Bednar Ivan , Min Qian , Södersten Per , Silberring Jerzy , Nyberg Fred , Thörnwall Madeleine 
Published: May 2005

AbstractA sensitive HPLC method has been described for quantitation of two cholecystokinin (CCK) peptides in discrete rat brain regions. Separation and quantitation was performed by the reversed‐phase HPLC combined with electrochemical detection. Analytical recoveries of the tetrapeptide (CCK‐4) and octapeptide‐sulphate (CCK‐8s) were 96% and 94%, respectively. The between assay coefficient of variation (CV) was less than 3% for both peptides. The within‐assay CV was 4% and 6% for CCK‐4 and CCK‐8s and the detection limit was 2 and 10 pmol/mL, respectively.For identification of structures, the peptides were fractionated by semi‐preparative HPLC using a novel SMART system for micropurification. The fractions were analysed by fast atom bombardment mass spectrometry (FAB MS) which confirmed the presence of both CCK‐4 and CCK‐8s in the rat brain tissue.
Isolation and purification of amyloglucosidase from Halobacterium sodomense
Authors: Chaga Grigoriy , Porath Jerker , Illéni Tibor 
Published: May 2005

AbstractAmyloglucosidase from Halobacterium sodomense was purified by a combination of hydrophobic interaction chromatography and immobilized metal ion affinity chromatography at analytical and preparative scale with 75% recovery. The enzyme was found to be a dimer of two different subunits with molecular weights of 72,000 and 82,000 D, respectively, combining in a 175,000 D native protein. The specific activity, KM, and amino acid composition of the enzyme was determined.
A simple method for plasma cannabinoid separation and quantification
Authors: Alemany G. , Gamundí A. , Nicolau M. C. , Saro D. 
Published: May 2005

AbstractA sensitive (up to nanogram level) method for resolving a cannabinoid mixture in plasma is described. Cannabinoids were extracted with a C‐18 Sep Pak cartridge and derivatized with dansylchloride. Then the derivatives were resolved on thin layer HPTLC silica plates which were developed and quantified by fluorescence densitometry at 340 nm.