Journal of chromatography最新文献_第8页

Recognition and separation of isoenzymes by metal chelates. Immobilized metal ion affinity partitioning of lactate dehydrogenase isoenzymes. 金属螯合物对同工酶的识别与分离。乳酸脱氢酶同工酶的固定化金属离子亲和分配。

Journal of chromatography Pub Date : 1993-07-30 DOI: 10.1016/0021-9673(93)80116-p

A Otto, G Birkenmeier

{"title":"Recognition and separation of isoenzymes by metal chelates. Immobilized metal ion affinity partitioning of lactate dehydrogenase isoenzymes.","authors":"A Otto, G Birkenmeier","doi":"10.1016/0021-9673(93)80116-p","DOIUrl":"https://doi.org/10.1016/0021-9673(93)80116-p","url":null,"abstract":"Poly(ethylene glycol) (PEG)-bound chelated metal ions partition preferentially into the top, PEG-rich, phase of a PEG-salt or PEG-dextran aqueous two-phase system. Extraction by this soluble affinity ligand of proteins is due to a selective interaction of the chelated metal ion with accessible histidine residues on the protein surface. Using Cu-iminodiacetate-PEG (Cu-IDA-PEG) the surface of lactate dehydrogenase (LDH) isoenzymes from different species was probed for the presence of metal chelate binding sites. It was demonstrated that the homotetramers (LDH-1)(H4) from rabbit, bovine and pig displayed weak binding to chelated copper whereas the M4-type isoenzymes (LDH-5) bound strongly to this ligand. The binding of the different heterotetramers increases as the number of M-type subunits increases. In contrast, the human isoenzymes are bound to chelated copper in a reversed sequence. The comparison of the affinity partitioning effect of Cu-IDA-PEG in PEG-salt and PEG-dextran systems revealed that the discriminatory effect of copper is promoted by high salt concentrations. Resolution of isoenzymes by multiple extraction using counter-current distribution provides valuable data on the partitioning of enzymes relative to that of the bulk proteins. The efficacy of metal chelate affinity partitioning for the purification of LDH from tissue samples by batchwise extraction was also demonstrated.","PeriodicalId":15508,"journal":{"name":"Journal of chromatography","volume":"644 1","pages":"25-33"},"PeriodicalIF":0.0,"publicationDate":"1993-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0021-9673(93)80116-p","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"18694736","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 24

Molecular mass determination of low-molecular-mass heparins. Application of wide collection angle measurements of light scattering using a high-performance gel permeation chromatographic system equipped with a low-angle laser light-scattering photometer. 低分子质量肝素的分子质量测定。基于低角度激光光散射光度计的高效凝胶渗透色谱系统在大采集角光散射测量中的应用。

Journal of chromatography Pub Date : 1993-07-30 DOI: 10.1016/0021-9673(93)80115-o

H Komatsu, K Yoshii, S Ishimitsu, S Okada, T Takahata

{"title":"Molecular mass determination of low-molecular-mass heparins. Application of wide collection angle measurements of light scattering using a high-performance gel permeation chromatographic system equipped with a low-angle laser light-scattering photometer.","authors":"H Komatsu, K Yoshii, S Ishimitsu, S Okada, T Takahata","doi":"10.1016/0021-9673(93)80115-o","DOIUrl":"https://doi.org/10.1016/0021-9673(93)80115-o","url":null,"abstract":"A high-performance gel permeation chromatographic system with on-line low-angle laser light-scattering detection (HPGPC-LALLS) was used to determine molecular masses of low-molecular-mass heparins (LMMHs). Measurements at wide and narrow collection angles were compared and the application of the HPGPC-LALLS method to small molecules, with molecular masses in the range 1000-10,000, was assessed. The molecular mass averages of fractionated heparins and commercially available LMMHs were also determined by ordinary HPGPC analysis using an LMMH molecular-mass calibrant, supplied by the National Institute for Biological Standards and Control for the calibration of columns. The LALLS intensity at the routinely used narrow collection angle (theta col = 1 degree) about doubled at the wide collection angle (theta col = 2 degrees) and the signal-to-noise ratio was improved. The present study thus indicates that wide collection angle measurement of light scattering allows the application of the HPGPC-LALLS method to very small biopolymers of molecular mass < 10,000.","PeriodicalId":15508,"journal":{"name":"Journal of chromatography","volume":"644 1","pages":"17-24"},"PeriodicalIF":0.0,"publicationDate":"1993-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0021-9673(93)80115-o","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19381269","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 22

Rapid isolation of polychlorinated biphenyls from milk by a combination of supercritical-fluid extraction and supercritical-fluid chromatography. 超临界流体萃取与超临界流体色谱相结合快速分离牛奶中的多氯联苯。

Journal of chromatography Pub Date : 1993-07-23 DOI: 10.1016/0021-9673(93)80577-u

A G Mills, T M Jefferies

{"title":"Rapid isolation of polychlorinated biphenyls from milk by a combination of supercritical-fluid extraction and supercritical-fluid chromatography.","authors":"A G Mills, T M Jefferies","doi":"10.1016/0021-9673(93)80577-u","DOIUrl":"https://doi.org/10.1016/0021-9673(93)80577-u","url":null,"abstract":"The extraction and isolation of polychlorinated biphenyls (PCBs) from sample matrices such as freeze-dried milk is a lengthy and expensive process that conventionally requires the isolation of microgram amounts of PCBs from large volumes of flammable organic solvents used in the extraction and chromatographic stages. Supercritical-fluid extraction (SFE) and chromatography (SFC) using carbon dioxide has been investigated as a replacement procedure using a Simplex optimisation approach to optimise the working conditions. The SFE conditions required to extract PCBs and milk fat from freeze-dried milk were investigated, and it was found that although extraction was rapid (10 min), the conditions required were identical so that there was no separation of PCBs and fat. However, SFC conditions have been developed that permit the resolution of PCBs from milk fat in 15 min. Thus, a combination of SFE and SFC have the potential to replace the existing methods of extraction and isolation with procedures that are quicker, cheaper, and avoid the use of flammable organic solvents.","PeriodicalId":15508,"journal":{"name":"Journal of chromatography","volume":"643 1-2","pages":"409-18"},"PeriodicalIF":0.0,"publicationDate":"1993-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0021-9673(93)80577-u","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19347372","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 10

Chromatographic methods in the determination of herbicide residues in crops, food and environmental samples. 作物、食品和环境样品中除草剂残留量的色谱测定方法。

Journal of chromatography Pub Date : 1993-07-23 DOI: 10.1016/0021-9673(93)80562-m

J Tekel, J Kovacicová

引用次数: 61

Organic micropollutants in Swiss sewage sludge. 瑞士污水污泥中的有机微污染物。

Journal of chromatography Pub Date : 1993-07-23 DOI: 10.1016/0021-9673(93)80574-r

P Frost, R Camenzind, A Mägert, R Bonjour, G Karlaganis

引用次数: 41

High-performance liquid chromatographic analysis of carbofuran residues in tomatoes grown in hydroponics. 水培番茄中呋喃残留量的高效液相色谱分析。

Journal of chromatography Pub Date : 1993-07-23 DOI: 10.1016/0021-9673(93)80570-x

C F Ling, G P Melian, F Jiminez-Conde, E Revilla

引用次数: 5

Environmental analysis of polychlorinated terphenyls: distribution in shellfish from the Ebro Delta (Mediterranean). 多氯联苯的环境分析:埃布罗三角洲(地中海)贝类的分布。

Journal of chromatography Pub Date : 1993-07-23 DOI: 10.1016/0021-9673(93)80576-t

M T Galceran, F J Santos, J Caixach, F Ventura, J Rivera

引用次数: 16

Assessment of ambient volatile hydrocarbons from tobacco smoke and from vehicle emissions. 评估烟草烟雾和车辆排放的环境挥发性碳氢化合物。

Journal of chromatography Pub Date : 1993-07-23 DOI: 10.1016/0021-9673(93)80542-g

G Barrefors, G Petersson

引用次数: 54

Detection of airborne cocaine and heroin by high-throughput liquid-absorption preconcentration and liquid chromatography-electrochemical detection. 高通量液吸收预富集-液相色谱-电化学检测空气中可卡因和海洛因。

Journal of chromatography Pub Date : 1993-07-23 DOI: 10.1016/0021-9673(93)80545-j

S Zaromb, J Alcaraz, D Lawson, C S Woo

引用次数: 12

Liquid chromatographic analysis of antibacterial drug residues in food products of animal origin. 动物源性食品中抗菌药物残留的液相色谱分析。

Journal of chromatography Pub Date : 1993-07-23 DOI: 10.1016/0021-9673(93)80573-q

B Shaikh, W A Moats

引用次数: 73