共查询到20条相似文献,搜索用时 15 毫秒
1.
Summary A reversed-phase high-performance liquid chromatographic (HPLC) method has been developed for the sensitive and highly selective
determination of histamine in plasma. This method includes selective extraction of histamine from plasma, pre-column derivatisation
in aqueous phase with o-phthaldialdehyde (OPA) and HPLC analysis. The fluorescence of the histamine-OPA-complex was monitored
at wavelengths of 350nm excitation and 450nm emission, after isocratic eluation with a mixture of 0.2 M NaCl and methanol.
The reproducibility of this method including extraction, derivatisation and detection of histamine was >95% in a range of
0.35–17.6 pmol. The HPLC precision was 99±1% at 4 pmol of histamine. The lower limit of detection was 88fmol. A significantly
increased concentration of plasma histamine was detected in patients (n=46) with various liver diseases (0.3–5.2 ng/ml). In
comparison the plasma histamine levels of healthy blood donors were in the range of 0.0–0.4 ng/ml (p<0.01). 相似文献
2.
A new procedure for the assay of D-amino acid oxidase activity has been developed. alpha-Ketoisovaleric acid, derived from D-valine, was estimated by high-performance liquid chromatography after reaction with o-phenylenediamine to give the corresponding quinoxalinol derivative. alpha-Ketovaleric acid was used as an internal standard to ensure the reproducibility of the method. As an example of application, kidney cortex homogenates were analyzed for their D-amino acid oxidase activity. The advantages of the presented procedure for the determination of the enzymatic activity in biological samples compared with previously reported procedures are discussed. 相似文献
3.
4.
Protein glycation has been implicated in the development of diabetic complications and other health disorders, which mainly arise from accumulation of advanced glycation endproducts (AGEs) in vivo. Methylglyoxal (MGO), a typical reactive intermediate carbonyl formed in early glycation process, can react non-enzymatically with N-terminal amino groups on proteins, leading to their inactivation and generation of detrimental AGEs. Recently, it was reported that activity of creatine kinase (CK, EC 2.7.3.2) could be reduced or even eliminated completely after incubation with MGO in vitro. CK activity is usually determined by conventional colorimetric assays. However, these methods are not appropriate for monitoring the influence of MGO on CK activity since MGO can also directly react with creatine, a substrate of CK. In this study, an efficient and much more accurate HPLC approach was established to investigate the effect of MGO on CK activity. Aminoguanidine was utilized to eliminate interference from the undesirable reaction between residual MGO and creatine. It was found that higher concentrations of MGO and longer incubation time for CK and MGO caused more pronounced reduction in CK activity. This HPLC method greatly facilitates acquisition of kinetic data about CK reaction and through further improvement it may be adopted to rapidly screen potential inhibitors of MGO-induced glycation. 相似文献
5.
G T Hill 《Journal of chromatography. A》1979,176(3):407-412
A high-performance liquid chromatographic method for the analysis of prostacyclin using a laboratory prepared reversed-phase column packing is described. A relative standard deviation of less than 1% was obtained for ten replicate injections. The system resolves prostacyclin from its hydrolysis product, 6-oxo-prostaglandin F1 alpha and from other prostaglandins present as impurities. These can be estimated to levels of approximately 0.5%. The separation of other unrelated prostaglandins by this method is briefly reported. 相似文献
6.
A fast, selective, and precise liquid chromatographic method for simultaneous, independent determination of kanamycins A and B is described. Sample components are separated on a pellicular cation exchanger and monitored by fluorescence using post-column on-line derivatization. Less than 0.35 mug of kanamycin B can be detected in as much as 7 mug kanamycin A injected. The detection limit for kanamycin A is less than 20 ng injected. Reproducibility of the entire chromatographic system is about 1% (2 theta) based upon repeated injections of standards. Precision of repeated process sample preparation is about 6% (2 theta). Chromatographic analysis time is less than 15 min per sample. 相似文献
7.
A rapid and specific ion-pair reversed-phase high-performance liquid chromatographic method was developed for the determination of bleomycins. The use of 5-microns particles of less adsorptive reversed-phase packings and sodium perchlorate as ion-pairing reagent permitted a short analysis time and the transferability of the separations on different batches of the reversed-phase materials. The detection sensitivity and precision of the method demonstrated that the system is suitable for routine analysis. 相似文献
8.
9.
10.
Summary Busulfan (Myleran; 1,4-bis-(methanesulfonyloxy) butane; BU) is a bifunctional alkylating agent used in clinical practice since
1959. It is currently included at high doses in conditioning regimens for bone marrow transplantation, usually in combination
with cyclo-phosphamide. A high-performance liquid chromatographic method has been developed for the determination of BU in
plasma. The basis of the assay is a derivatization with sodium diethyldithiocarbamate at 32°C in the presence of 1-bromo-1-deoxy-3,6-anhydrogalactitol
as internal standard. Analysis is performed on a cyano column with heptane-isopropanol-glacial acetic acid as mobile phase
and UV detection at 280 nm. The calibration graph was linear in the concentration range 0.18–46.40 μM BU in plasma. The limit
of detection was 0.1 μM. The precision and accuracy were between the limits required by good laboratory practice.
Presented at Balaton Symposium on High-Performance Separation Methods, Siófok, Hungary, september 1–3, 1999 相似文献
11.
12.
13.
Lyle D. Bighley Dale E. Wurster Diana Cruden-Loeb Robert V. Smith 《Journal of chromatography. A》1975,110(2):375-380
A sensitive analysis of pentaerythritol in plasma has been devised, based on the formation or its tetra-p-methoxybenzoate derivative and high-performance liquid chromatography employing an ultraviolet photometric detector. The method permits analysis of pentaerythritol in the ppm range. 相似文献
14.
15.
16.
17.
18.
Sánchez-Machado DI López-Hernández J Paseiro-Losada P 《Journal of chromatography. A》2002,976(1-2):277-284
A high-performance liquid chromatographic (HPLC) method for the microscale determination of alpha-tocopherol in macroalgae is reported. The method includes microscale saponification and extraction with n-hexane. The presence of alpha-tocopherol in macroalgae samples was confirmed by HPLC-MS. Alpha-tocopherol levels as determined in samples by HPLC with UV and fluorescence detection did not differ significantly; however, fluorescence detection has a higher sensitivity (detection limit 10.4 ng/ml, vs. 104 ng/ml with UV detection), as well as good precision (relative standard deviation 1.81%) and recovery (94.3%). Fluorescence detection is also faster. We used this method to determine the alpha-tocopherol contents of four commercial macroalgae products from northwest Spain as part of nutritional studies in dehydrated Himanthalia elongata and Laminaria ochroleuca, and also in canned Himanthalia elongata and Saccorhiza polychides. 相似文献
19.
20.