We describe a simple method for extracting 3-methoxy-4-hydroxyphenylglycol (MHPG) from plasma. The sample is applied to a 1-mL "Extrelut" column (EM Industries) and eluted 15 min later with ethyl acetate. After mixing the eluate with pentane and back-extraction into water, we inject 25 or 50 microL of the aqueous phase onto a Beckman 15 cm x 4.6 mm (i.d.) column packed with 5-micron ODS particl...

The purpose of this investigation is to develop a rapid and simple method for the assessment of organophosphorus pesticides in bovine muscle by using solid-phase extraction (SPE). After extraction with ethyl acetate (EtOAc) the homogenate is centrifuged and filtered through sodium sulfate. The fat is precipitated in methanol by cooling and the extract is diluted with water and passed through a ...

The suitability of analytical protocol for determination of sulfonamides in honey was investigated. Sulfonamides were extracted from honey with acetate buffer, and cleaned up by solid phase extraction (SPE) procedure. The liquid chromatography (LC) separation was carried out on RP C18 column and sulfonamides were monitored with fluorescence detector, after pre-column derivatisation. Recoveries ...

A novel antiherpetic agent, fattiviracin A1, was isolated from the culture broth of strain No. 2445 identified as Streptomyces microflavus. It was purified through 1-butanol extraction, column chromatographies on Diaion HP-10 and silica gel and HPLC using a reverse phase column. The structure of fattiviracin A1 was determined by several spectroscopic experiments and chemical degradations. It is...

isolated five known iridoids glycosides (scrophuloside a, harpagoside b, 5-hydroxyloganin, 8-o-acetylharpagide and 6-o-methyl,1-glucopyranosyl catalpol ),one phenyl ethanoid glycoside (verbascoside) and a phenyl ethanol amine (2-(4-chlorobenzyl amino) ethanol ) compound from the methanolic extract of aerial parts of scrophularia oxysepala using by high performance liquid chromatography based on...

a rapid and sensitive hplc method has been developed for the quantification of mirtazapine (mrz), a noradrenergic and specific serotonergic inhibitor antidepressant (nassa) and its two major metabolites n-desmethylmirtazapine (ndm) and 8-hydroxymirtazapine (8-ohm) in human plasma. the separation was achieved using chromolith c18 column and a mobile phase of acetonitrile: phosphate buffer (ph=3,...

This is a simple, rapid, sensitive method for routine quantification of the polyamine putrescine (1,4-diaminobutane) in cerebrospinal fluid. Sample preparation involves protein precipitation, acid hydrolysis for 18 h (if total putrescine is to be measured), pre-column derivatization with o-phthalaldehyde, and extraction into acetonitrile. The derivative is separated and quantified by "high-perf...

Polychlorinated biphenyls (PCBs) in waste oil are typically analyzed by GC-ECD or GC/MS after solid phase extraction (SPE) cleanup. However, not all problematic matrix components are completely removed during cleanup and are injected into the analytical system, thereby contaminating the column and the detector. In this application, a practical example of backflushing is presented using the Agil...

A quantitative HPLC – fluorescence method for the simultaneous determination of sulfamerazine (SMR) and sulfamethoxazole (SMX) in honey has been developed. Sample pretreatment included acidic hydrolysis, followed by solid phase extraction (SPE) procedure. The liquid chromatography (LC) separation was carried out on RP C 18 column and sulfonamides were detected by fluorescence detector after pre...

A new fast screening method has been developed for the analysis of organochlorine pesticides in water that takes less than 10 min to perform and has detection limits of the order of 10 ng l21. Pesticide extraction was achieved by solid-phase microextraction and the separation was performed using a micro-bore (0.1 mm) capillary column. A laboratory-built cryotrap system was used to focus the ana...