bluuebunny/crossref_metadata_2025_split huggingface dataset:
A new method for the quantitation of aflatoxin M1 in urine by high performance liquid chromatography and its application to the etiologic study of hepatoma
Authors: Liu Zhong‐he , Tu Wen‐sheng , Li Dan‐rong , Li Yuan‐dong , Xie Chong‐hu , Yang Yin‐zhong , Qin Bing‐bing 
Published: May 2005

AbstractA high performance liquid chromatographic (HPLC) method for the analysis of aflotoxin M1 (AFM1) in urine is described. Urine samples were treated with saturated lead acetate and AFM1 was extracted with chloroform. After washing with water to remove impurities the compound was derivatized with trifluoracetic acid and the AFM1 derivative was analyzed quantitatively by HPLC. The sample pretreatment is simple and more selective. A good line correlation between AFM1 peak height and its concentration was obtained when AFM1 content was in the range of 50–400 pg. The ratio of recovery was 87.42%. Sensitivity is 0.01 ppb. The method is applicable to trace analysis. Results in urine of residents who live in the high/low liver cancer incidence area in Fushui county were the same as that of previous epidemiological investigation.
Chemiluminescence high performance liquid chromatography of corticosteroids using lucigenin as post‐column reagent
Authors: Takeda Motoko , Maeda Masako , Tsuji Akio 
Published: May 2005

AbstractA chemiluminescence high performance liquid chromatographic method for the determination of corticosteroids and tetrahydrocorticosteroids has been developed. Corticosteroids and their metabolites extracted from urine samples were separated using an ODS column and a mixture of methanol + water + 0.01 M sodium acetate solution (70:30:5) as eluent. The eluent from the column was mixed with the chemiluminescent solution containing lucigenin and Triton X‐100 and a 0.28 M KOH solution by pumps and monitored by a chemiluminescence detector. No interference was encountered and the method is both precise and reproducible.
Determination of individual bile acids in serum by high performance liquid chromatography
Authors: Wang Ganfeng , Stacey Neill H. , Earl John 
Published: May 2005

AbstractA high performance liquid chromatographic (HPLC) method for analysis of 4 free and 8 conjugated bile acids in submicromolar quantities in serum is described using precolumn derivatization with 4‐bromomethyl‐7‐methoxy‐coumarin (BMC) and fluorescence detection. Bile acids were extracted from serum with 0.4 M sodium bicarbonate, adsorbed onto a Sep‐Pak C18 cartridge and eluted with methanol. The extract was derivatized with BMC in acetonitrile using 18‐crown‐6 crown ether as catalyst and the BMC labelled glycine conjugates and free bile acids were analysed using acetonitrile + methanol + water gradient elution and detection at 320/385 nm.Using a novel and simple approach, taurine conjugates were isolated by extracting the dried, derivatized material with water, in contrast to previous methods which required column chromatography cleanup to isolate the taurine conjugates prior to derivatization. The isolated taurine conjugates were then hydrolysed enzymatically, extracted, derivatized and analysed as free‐bile acids.Recoveries of individual bile acids varied from 83 – 96% for free and glycine conjugates and 72 – 83% for taurine conjugates. Coefficients of variation were in the range of 5.1 – 12.5%. In addition to the simpler and shorter procedure for taurine conjugates, this method has increased sensitivity over most other procedures and improved HPLC separation for the various bile acids and conjugates with equivalent recovery and reproducibility compared with other published methods.
Gel filtration high performance liquid chromatography of envelope polypeptide variants of herpes simplex type 1 strains
Authors: Al‐Ahdal Mohammed N. , Qadri S. M. Hussain , McGarry Thomas J. 
Published: May 2005

AbstractHigh performance liquid chromatography (HPLC) with a TSK‐4000SW gel filtration column was used to compare envelope polypeptides from four strains of herpes simplex virus type 1 (HSV‐1). The chromatographic profiles demonstrated polypeptide variability among three clinical strains and the wild‐type F strain. Radioimmunoprecipitation of the HPLC fractions with polyclonal anti‐HSV‐1 followed by SDS‐polyacrylamide gel electrophoresis (PAGE) of the immunoprecipitates revealed molecular weight differences of various polypeptides in fractions from the area containing major peaks. This HPLC method could prove useful for the analysis of polypeptide polymorphism in clinical isolates of HSV‐1, as well as in other viruses.
Studies on the determination and degradation of pyrimethamine in mammals
Authors: Kumar Reena , Kaushik P. , Sharma C. B. 
Published: May 2005

AbstractTreatment of pyrimethamine with blood plasma in vitro yields a metabolite which is also produced when the drug is administered through intravenous injection in the rat. A thin layer liquid chromatographic method for quantitative and qualitative determination of pyrimethamine and its metabolite in plasma and biological tissues is described.
Determination of amines, amine metabolites and some amine metabolizing enzymes by high performance liquid chromatography
Authors: Bháird Nóirín Nic a' , McCrodden John M. , Wheatley Anthony M. , Harrington Michael C. , Sullivan James P. , Tipton Keith F. 
Published: May 2005

AbstractSome useful high performance liquid chromatographic methods for the determination of amines, amine metabolites and amine metabolizing enzymes are described. These include the separation of tyramine in wines and beers, determination of tryptamine in urine, assay of monoamine oxidase and catechol‐O‐methyltransferase and analysis of amine‐aldehyde condensation products.
Enzyme degradation, high performance liquid chromatography and liquid secondary ion mass spectrometry in the analysis of glycoproteins
Authors: Smith Kevin D. , Harbin Anne‐Marie , Carruthers Robert A. , Lawson Alexander M. , Hounsell Elizabeth F. 
Published: May 2005

AbstractAnalysis of small amounts of glycoproteins by high performance liquid chromatography (HPLC) and liquid secondary ion mass spectrometry (LSIMS) together with enzyme digestion has been investigated using fetuin as a model. Preliminary data indicates that 71% of the expected peptides were detected by LSIMS analysis of 200 pmol total digest. HPLC profiles of peptides and glycopeptides were obtained from 2 nmol of digest using a reversed phase (C18) column eluted in a solvent system containing TFA, water and acetonitrile. This has provided glycopeptides for subsequent oligosaccharide analysis. Strategies are reviewed for the chromatographic characterization of oligosaccharides following their release from glycopeptides by chemical and enzymatic procedures.
A reversed phase liquid chromatographic method for the simultaneous determination of several common penicillins in human serum
Authors: Mendez‐Alvarez E. , Soto‐Otero R. , Sierra‐Paredes G. , Aguilar‐Veiga E. , Galan‐Valiente J. , Sierra‐Marcuño G. 
Published: May 2005

AbstractA rapid and sensitive high performance liquid chromatographic method is described for the simultaneous determination of benzylpenicillin, ampicillin, phenoxymethylpenicillin, cloxacillin, dicloxacillin and nafcillin in small samples of human serum. The chromatographic system involves the use of a Spherisorb ODS reversed phase column and a gradient elution with 1 mM ammonium acetate buffer/acetonitrile (from 90:10 to 75:25 in 15 min). Detection and quantification are monitored by UV absorption at 208 nm. The compounds are extracted with dichloromethane, using tetrabutylammonium hydrogen sulfate neutralized with sodium hydroxide and buffered with borate as an ion pairing reagent; β‐hydroxyethyltheophylline is added as an internal standard. Our results show that the method is accurate and reproducible, allowing quantification of serum levels of assayed penicillins (0.5–50 μg/mL) without interference from other drugs commonly used in therapy. Recoveries were generally greater than 79.4%.
Chromatographic methods for the analysis of basic neurotransmitters and their acidic metabolites
Authors: Yi Zhen , Brown Phyllis R. 
Published: May 2005

AbstractChromatographic techniques for the determination of trace amounts of neurotransmitters were reviewed. The two techniques found to be most useful were GC‐MS and the reversed‐phase mode of HPLC with an electrochemical or fluorescent detector. For structure determination or unequivocal peak identification, GC‐MS is the method of choice. In addition the limits of detection of GC‐MS were better than those obtained by HPLC. However for routine analyses, HPLC is now being used in studies of mental illness and other diseases. Good resolution, reproducibility and sensitivity can be obtained without the derivatisation steps required for GC‐MS, and catecholamines, serotonin, and their acidic metabolites can be concomitantly determined in one analysis.
High performance liquid chromatography as a tool in the definition of abnormalities in monoamine and tryptophan metabolites in cerebrospinal fluid from patients with neurological disorders
Authors: Baig S. , Halawa I. , Qureshi G. A. 
Published: May 2005

AbstractIn this study we report the levels of 3‐methoxy‐4‐hydroxyphenylglycol, 3,4‐dihydroxyphenylacetic acid, homovallinic acid, tryptophan, 5‐hydroxyindole‐3‐acetic acid and serotonin in lumbar cerebrospinal fluid (CSF) from patients with multiple sclerosis, cerebrovascular disease and muscular tension headache the latter, as healthy controls. The separation of these substances was performed on a reversed phase column by ion pair high performance liquid chromatography and detection was made by a glassy carbon electrode set at +900 mV vs Ag+/AgCI. The whole separation was achieved within 25 min. Concentrations of all substances (10‐1000 pmole/L) were linearly proportional to areas obtained. The system is sensitive, stable and reproducible. The significance of CSF levels of these metabolites from patient groups compared with healthy controls are discussed.
Biomedical applications of chiral liquid chromatography
Authors: Camilleri Patrick 
Published: May 2005

AbstractMany drugs are recemic and therefore much effort has to be devoted towards the stereoselective synthesis of the most effective or less harmful component of a racemic mixture. High performance liquid chromatography will play an important role in the clinical analysis of racemic drugs in anticipation of regulations that are currently being discussed and are expected to be enforced by the end of this decade. In this review a number of methods for chiral resolution are outlined. These include the formation of diastereoisomers and the use of chiral stationary phases or chiral mobile phase additives.
Identification and quantification of lipids from rabbit Harderian glands by gas chromatography/mass spectrometry
Authors: Harvey D. J. 
Published: May 2005

AbstractLipids from hydrolysed extracts of Harderian glands from the rabbit were examined as trimethylsilyl, acetonide, nicotinate and picolinyl esters and shown to consist mainly of acylated glycerol ethers and acylated hydroxyglycerol ethers. Constitutents amounting to 98.8% of the recovered secretion were identified. Fatty acids were mainly normal, saturated compounds with chain legths from 12 to 24 carbon atoms; n‐16:0 and n‐18:0 accounted for about 40% of the identified acids. Small concentrations of iso‐17:0 and unsaturated acids with 18‐carbon chains were also identified. Fatty alcohols were again mainly normal‐unsaturated compounds; the chains varied from C18 to C25 with 20:0‐OH and 22:0‐OH being the most abundant. Three types of 1‐alkyl glycerols were found. The major constituents had normal, saturated chains with from 14 to 23 carbon atoms with the even carbon chains predominating. These were accompanied by hydroxylated derivatives of the 16‐ and 18‐carbon glycerol ethers with hydroxy groups in the 10, 11 and 12 positions. Branched‐chain glycerol ethers were of low concentration and contained predominently iso chains. Many of these compounds have not been reported before in this secretion. Low concentrations of the previously reported hydroxy acids with n‐C14, ‐C15 and ‐C16 chains were also found. Nicotinate derivatives were applied to the structural determination of glycerol ethers for the first time and shown to reveal the position of methyl branch points in an analogous manner to that previously shown for mono‐ and di‐hydric alcohols. Acids were identified as picolinyl esters.
Microdetermination of hyaluronic acid in human urine by high performance liquid chromatography
Authors: Akiyama Hiroshi , Toyoda Hidenao , Yamanashi Shigeyuki , Sagehashi Yoshinori , Toida Toshihiko , Imanari Toshio 
Published: May 2005

AbstractA high performance liquid chromatographic (HPLC) system is described for determination of the unsaturated disaccharide (ΔDi‐HA) derived from hyaluronic acid (HA) in human urine by digestion with hyaluronidase SD. The effects of eluents on the separation of ΔDi‐HA and ΔDi‐OS, which is derived from the reaction of chondroitin with the enzyme, have been studied. The established chromatographic conditions were as follows–column: a stainless steel tube (4 mm i.d. × 250 mm) packed with TSKgel NH2‐60; eluent: a mixture of acetonitrile and 0.1 M Tris‐HCI buffer containing 0.1 M boric acid and 10 mM sodium sulphate, pH 7.0 (64:36, v/v). The strong fluorescence of unsaturated disaccharide after the reaction with 2‐cyanoacetamide in alkaline medium was used for post‐column detection. The calibration curve for ΔDi‐HA was linear in the range 5 pmol‐5 nmol with a practical detection limit of 2 pmol. The assay coefficients of variation (n = 5) at 200 pmol for ΔDi‐HA and ΔDi‐OS were 1.7 and 1.5%, respectively. This HPLC system has been applied to the determination of HA in human urine.
Plasma B‐6 vitamer and plasma and urinary 4‐pyridoxic acid concentrations in young women as determined using high performance liquid chromatography
Authors: Driskell Judy A. , Chrisley Barbara Mc. 
Published: May 2005

AbstractPlasma B‐6 vitamer and plasma and urinary 4‐pyridoxic acid concentrations of 21 young white women, 21–27 years, having radiomonitored pyridoxal 5′‐phosphate and coenzyme stimulation of erythrocyte alanine amino‐transferase activities indicative of adequate vitamin B‐6 status were determined in an effort to establish normal ranges for plasma B‐6 vitamers. B‐6 vitamers and 4‐pyridoxic acid were quantitated using reversed phase high performance liquid chromatography with fluorometric and ultraviolet detection. Pyridoxal phosphate values obtained by radioenzymatic and chromatographic, fluorometric and ultraviolet, assays were highly correlated as were pyridoxine phosphate values determined using both detectors. The B‐6 vitamer and 4‐pyridoxic acid values of these subjects should be of use in the establishment of normal ranges of these congeners in women.
Comparative performance of ion exchange and ion‐paired reversed phase high performance liquid chromatography for the determination of nucleotides in biological samples
Authors: Perrett David , Bhusate Lekha , Patel Jayshree , Herbert Karl 
Published: May 2005

AbstractWe have compared anion exchange chromatography on APS‐Hypersil (4.6 × 100 mm) eluted with a phosphate gradient with reversed phase chromatography on ODS‐Hypersil (4.6 × 100 mm) in the presence of either tetrabutylammonium (TBA) or triethylammonium (TEA) ions with a methanol gradient. The systems have been compared both for ease of operation and for their resolving power with standard mixtures and acid extracts of both normal red cells (RBC) and ischaemic tissues. The two chromatographic modes exhibited similar separating efficiencies for standard mixtures of nucleotides but retention times were most stable using reversed phase liquid chromatography (RPLC) with TEA. Anion exchange columns slowly lost ion exchange capacity but selectivity was unchanged. RPLC in the presence of TBA gave reproducibile capacity factors only when operated isocratically due to irreversible changes to the silica surface. For RBCs the RPLC with TEA and anion exchange sysems resolved 17 and 15 peaks, respectively, and for the ischaemic samples 22 and 14 peaks, respectively. However, nucleosides and bases were also resolved by the ODS column causing chromatographic crowding and uncertain peak identification.
Rapid high voltage isoelectric focusing of proteins in rod gels
Authors: Das Joachim 
Published: May 2005

AbstractA rapid procedure of isoelectric focusing (IEF) of proteins in polyacrylamide rod gels (i.d., 1.1 mm; lenght, 7.5 cm) is described. The time required for IEF can be reduced to 0.5 h by using high voltages up to 3000 V in the presence or absence of urea in the gels. When used as the first dimension of a two‐dimensional technique for IEF sodium dodecyl sulphate electrophoresis, high voltage IEF gives smaller protein spots on the second dimension gel, associated with an increase in resolution. The method has been tested by a two‐dimensional separation of an eye sample of the goodeid fish Xenotoca eiseni.
Determination of 2‐chloro‐2′‐deoxyadenosine in human plasma
Authors: Liliemark Jan , Pettersson Birgitta , Juliusson Gunnar 
Published: May 2005

AbstractThe first high performance liquid chromatographic method for determination of the plasma concentration of 2‐chloro‐2′‐deoxyadenosine (CdA) in patients, which is significantly more sensitive than the previously used RIA method, is presented. CdA is a purine analogue with useful clinical activity against lymphoproliferative disorders and it has recently been found to be the single most active agent in the treatment of hairy cell leukaemia. Guaneran (6‐nitroimidazol‐6‐thioguanine) was added to 1 mL plasma as the internal standard and CdA was extracted using ethyl acetate. A Perkin‐Elmer C18, 3 μ, 8 cm column was used for the separation of CdA and the internal standard from endogenous compounds in the sample with a mixture of sodium phosphate buffer 10 mM, methanol and acetonitrile (85:10:5, pH = 3.0) as the mobile phase. The sensitivity of the method (1 nM) allows the determination of CdA in plasma 24 h after the administration of 0.14 m/kg as a 2 h infusion.
Reversed phase high performance liquid chromatographic separation of hydroxy steroidal unsaturated esters and their hemisuccinates
Authors: Drašar Pavel , Pouzar Vladimir , Černỳ Ivan , Procházka Miroskav 
Published: May 2005

AbstractThe high performance liquid chromatographic (HPLC) separation and identification of 12 isomeric and/or highly chemically related steroids with an unsaturated ester moiety at position 17β has been achieved. The main stereochemical features of the steroid skelton cover 3α/β or Δ, and 20 E/Z, bearing the alcohol or hemisuccinate group at the 3 position. The isocratic reversed phase C18 HPLC separation employed ethanol, methanol and its mixtures with water or 0.01 M phosphoric acid as the mobile phase. The best separaton of the respective alcohols from their hemiscuccinates has been achieved with 20% of aqueous phase content. The best separation among isomeric or related steroids has been achieved with methanol: water 8:2 and 85:15 and similar systems containing phosphoric acid.
Determination of the level of the core of 2′,5′‐oligoadenylates by high performance liquid chromatography
Authors: Suzuki H. , Buonamassa D. Tornese 
Published: May 2005

AbstractA simple and rapid method for analysis of the core of 2′,5′‐oligoadenylates, mainly based on the use of high performance liquid chromatography (HPLC), is described. Perchloric acid extracts of tissues or cells were first treated with nuclease P1. Portions of the extracts were then digested with alkaline phosphatase. HPLC analysis of the extracts was performed on a column system composed of an Ultrasphere ODS precolumn (4.6 × 45 mm) and an Ultrasphere Octyl column (4.6 × 250 mm) by stepwise elution using a 50 mM ammonium phosphate buffer, pH7, containing 3.5 and 7% methanol. Three species of the core of 2′,5′‐oligoadenylates (dimer, trimer and tetramer) from a number of samples were eluted separately with 7% methanol, and the concentration of each core was directly estimated using constant values calculated with the standard core. The level of the core of 2′,5′‐oligoadenylates in tissues and cells determined by our method is similar to that reported by other authors who used biological, radiobinding or radioimmunological assays.
Favourable biospecific reactivity of blood group B antigenic trisaccharide chemically attached to poly‐N‐(2‐hydroxyethyl)acrylamide‐coated porous glass
Authors: Ivanov Alexander E. , Bovin Nickolay V. , Korchagina Elena Yu. , Zubov Vitaly P. 
Published: May 2005

AbstractBlood group B antigenic trisaccharide‐β‐aminopropyl glycoside (B‐TSAP) covalently attached to poly‐N‐(2‐hydroxyethyl)acrylamide‐coated porous glass interacts with anti‐B monoclonal antibodies faster than the ligand coupled to CNBr‐activated Sepharose 4B and Affi‐Gel 10. Rates of hydrophobic adsorption of antibodies on the butyl derivatives of the same supports were measured to evaluate the diffusion input to overall kinetics. The lowest average affinity adsorption time [t1(aff) = 250 s] observed for polymer‐coated glass probably arises because of the flexibility of the extended segments of chemisorbed N‐substituted polyacrylamide acting as effective spacer arms.
Peroxyoxalate chemiluminescence detection of condensates of malondialdehyde with thiobarbituric acids using a flow system
Authors: Nakashima Kenichiro , Nagata Masahiko , Takahashi Masakatsu , Akiyama Shuzo 
Published: May 2005

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 fluorescent derivatizing reagent.
Combined application of analytical high performance thin layer chromatography and electroblotting for the detection of anti‐ganglioside antibodies in human sera
Authors: Ritter K. , Schaade L. , Thomssen R. , Grunow E. 
Published: May 2005

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 tissues.