We identify protonation sites and study the competition of statistical fragmentation with localized bond cleavage after site-selective nitrogen 1s core-excitation by mass spectrometric detection gas-phase oligonucleotide cations.

The article presents the results of research aimed at developing a method for directly establishing molecular structure components liquid hydrocarbon fluids without use mass spectrometric detection.

Modifications of the ozonolysis and Schiff staining of plasma lipoproteins reduce 11 pre-spectrometric steps to 3. Picrate denaturation of the lipoproteins and absorption spectrometry directly on the wet opaque membrane increase the sensitivity; the volume of sub-specimen needed per length of application site is reduced from 0.7 to 0.1 Atl/mm. Reasonably good proportionality between the total l...

We describe an analytical protocol for characterizing the molecular structure of hemoglobin (Hb) Lepore variants by using two different mass-spectrometric approaches. The first method consists of direct examination of the chromatographically separated hybrid globins by electro-spray mass spectrometry; the variant Lepore globin is identified through the accurate determination of its molecular ma...

Phosphorylation of potassium channels affects their function and plays a major role in regulating cell physiology. Here, we review previous studies of potassium channel phosphorylation, focusing first on studies employing site-directed mutagenesis of recombinant channels expressed in heterologous cells. We then discuss recent mass spectrometric-based approaches to identify and quantify phosphor...

We describe a combined gas-chromatographic mass-spectrometric method for determination of theophylline in whole blood. With use of a probability-based matching approach, the extensive gas-chromatographic interference did not affect mass-spectrometric quantitation of theophylline. Concentrations expected and found were linearly related from 1 to 60 mg/liter; the run-to-run coefficient of variati...

Spectrometric techniques for the analysis of trace lead have developed rapidly due to the increasing need for accurate measurements at extremely low levels of this element in diverse matrices. This review covers separation and preconcentration procedures, and considers the features of the application with several spectrometric techniques. The use of an appropriate sample handling technique is a...

Spectrometric techniques for the analysis of trace lead have developed rapidly due to the increasing need for accurate measurements at extremely low levels of this element in diverse matrices. This review covers separation and preconcentration procedures, and considers the features of the application with several spectrometric techniques. The use of an appropriate sample handling technique is a...