Elution

In this work, a solid phase spectrophotometric method in association with flow injection analysis for formaldehyde determination has been developed with direct measurement of light-absorption in C 18 material. The 3,5-diacetyl-1,4-dihydrolutidine produced from the reaction between ...

Correct identification of a peptide sequence from MS/MS data is still a challenging research problem, particularly in proteomic analyses of higher eukaryotes where protein databases are large. The scoring methods of search programs often generate cases where incorrect ...

Ammonium hydrogencarbonate buffer has been found to be especially useful for high-pH HPLC analysis of samples from both combinatorial and medicinal chemistry sources. Satisfactory results were obtained by the standard diode array, evaporative light-scattering ...

The aim of this work was to compare macro- and micromorphological characteristics and flavonoid composition of some Epilobium species and commercial willow-herbs for their authentication and quality control. In order to determine the flavonoid composition of extracts, the flavonol-glycosides were also hydrolised quantitatively to their aglycones. Before and after hydrolysis flavonoid fingerprints were studied by high-performance liquid chromatography using two different gradient mobile phase systems. Flavonoid composition was found to be suitable for the authentication of Epilobium species and commercial willow-herbs as an alternative to the current phytochemical study and time-consuming microscopic procedures [1]. The combined HPLC analysis of free flavonoid-aglycones and glycosides, developed in our laboratory can be used for the quality control of willow-herb samples and various commercial preparations.

There is a need to develop technologies that can remove toxic heavy metal ions found in wastewaters. Microorganisms are known to remove heavy metal ions from water. In this study the potential of the fungus Aspergillus niger to remove lead, cadmium, copper and nickel ...

Correct identification of a peptide sequence from MS/MS data is still a challenging research problem, particularly in proteomic analyses of higher eukaryotes where protein databases are large. The scoring methods of search programs often generate cases where incorrect ...

An on-line solid phase extraction (SPE) preconcentration system coupled to flame atomic absorption spectrometer (FAAS) was developed for determination of copper and cadmium at μg L −1 level. The method is based on the on-line retention of copper and cadmium on a ...

A headspace solid-phase micro-extraction (HS-SPME) method was developed and optimized for gas chromatographic separation and determination of commonly found organotin compounds in human urine after potential exposure. Butyl- and phenyltin compounds were in situ derivatized to ethylated derivatives by sodium tetraethylborate (NaBEt(4)) directly in the urine matrix. The relevant parameters affecting the yield of the SPME procedure were examined using tetrabutyltin as internal standard. The method was optimized for direct use in the analysis of undiluted human urine samples and mono-, di- and tri-substituted butyl- and phenyltin compounds could be determined after a 15-min headspace extraction time at room temperature. The selectivity of the microwave-induced plasma atomic emission detector (MIP-AED) as an element specific detector in combination with the relatively selective sample preparation technique of HS-SPME allowed the interference-free detection of the organotin compounds in a...

In this paper we describe an easy and efficient way to pack mini-columns and use them in the Biomek 1000 Automated Laboratory Workstation. These procedures allow for automated column equilibration, column washing, sample loading and elution, and utilization of commercially available components. Various resins can be packed, allowing for automation of a variety of procedures in which minicolumns are used.