Electrospray mass spectrometry ESMS

The typical solution present in the capillary consists of a polar solvent in which electrolytes are soluble. As an example, we can use methanol as solvent and a simple salt like NaCl or BHC1, where B is an organic base, as the solute. Low electrolyte concentrations, 10-5-10 3 mol/L (M), are typically used in electrospray mass spectrometry (ESMS). For simplicity we will consider only the positive ion mode in the subsequent discussion. 

Electrospray mass spectrometry (ESMS) is a powerful tool for gaining insight into the self-assembly process itself by allowing the identification of the species present in various solutions of such complicated mixtures of self-assembling ligands and metal ions leading up to the final architecture [9.94, 9.95]. 

Electrospray mass spectrometry (ESMS) — The electrospray component of ESMS [i] provides a very soft method of transferring ions from solution to the gas phase with minimal risk of decomposition and fragmentation of ions prior to their determination by mass spectrometry. Ideally suited for the determination of charged solution species which are frequently generated in electrochemical experiments [ii]. 

Applications of electrospray mass spectrometry (ESMS) to the study of reactions mediated by transition-metal complexes are reviewed. ESMS has become increasingly popular as an analytical tool in inorganic and organometallic chemistry, in particular with regard to the identification of short-lived intermediates of catalytic cycles. Going one step further, the coupling of electrospray ionization to ion-molecule techniques in the gas phase yields detailed information about single reaction steps of catalytic cycles. This method allows the study of transient intermediates that have previously not been within reach of condensed-phase techniques on both a qualitative and quantitative level. 

Experimenters notes The refluxing acid step hydrolyzes the ester and the amide groups and decarboxylates the diacid (Fig. 1). When long alkyl chains are employed (e.g., >14 carbons), this may require longer than 24 h. The reaction should be monitored by electrospray mass spectrometry (ESMS) to ensure it is complete. Again, for long alkyl chain Laas it is imperative that a very large flask be used in the acid reflux step, and this reaction should be monitored carefully. If insufficient headspace over the reaction is allowed it can explode out of the condenser. 

Electrospray mass spectrometry (ESMS) was also used to substantiate the presence of e-N-acetyllysine in rbST and rpST. ESMS (Fig. 6) analyses of normal pi (Fig. 

Recombinant wild type hIL-ip, the K138C mutant and the K138C, R4A, L6A triple mutant (mutant 1) were isolated from the soluble fraction of E. coli lysates by ammonium sulfate fractionation and hydrophobic interaction chromatography. The purified proteins were characterized by SDS-PAGE, western blots, N-terminal sequence, size exclusion chromatography (SEC), isoelectric focusing (lEF), matrix assisted laser desorption ionization mass spectrometry (MALDI-MS), and electrospray mass spectrometry (ESMS). 

Confirmation of taxol production by H10BA2 followed the protocol established in our investigation of taxol production by T. andreanae [1]. HPLC columns were calibrated with authentic taxol to determine retention times, and appropriate fungal eluants were examined by TLC, CIEIA and mass spectrometry [1]. Comparison of fast atom bombardment (FABMS) and electrospray mass spectrometry (ESMS) of yew-derived taxol (provided by Bristol Myers Squibb) with taxol isolated from P. raistrickii using CIEIA-guided fractionation showed that these metabolites are... 

In conjunction with XAS and other techniques, such as EPR spectroscopy for the characterization of Cr(V) complexes, electrospray mass spectrometry (ESMS) is an extremely useful tool. Often the parent peak for even reactive Cr(V) and Cr(Vl) complexes dominates the spectrum and allows important structural information to be elucidated (92, 93). In water, where complex mixtures are often involved, it is a useful technique to aid in the speciation of complexes, although the redox chemistry and the extensive fragmentation that tends to occur (94) means that the results need to be interpreted with care (usually in conjunction with other independent information on the speciation) (22, 23, 34, 95). Recently, ESMS has been applied to studies of biologically relevant Cr(lll) complexes (95) and Cr -DNA interactions (96). Thus, ESMS is applicable to all oxidation states and will no doubt contribute to further the characterization of reactive Cr species of relevance to cancer, dietary supplements, and naturally occurring Cr complexes with biomolecules. 

Taylor Cone-Jets and Electrospray Mass Spectrometry (ESMS). 

Substituted iron carbonyl complexes ineluding Fe(C0)3 As(C6H40Me-/>)3)2 and Fe(C0)4 As(C6H40Me-/>)3) were examined by electrospray mass spectrometry (ESMS). Whereas the related compound Fe(CO>3(AsPh3)2 did not give an ESMS spectrum, the methoxy-substituted compounds did. This was attributed to the presence of protonatable methoxy groups. Both the monosubstituted and disubstituted compounds were observed in a crude... 

---