Tandem structure selective detection

LC-ISP-MS proved to be an attractive approach for the determination of semduramicin in chicken liver (120). Tandem MS using CID of the molecular ions could further enhance the specificity, providing structure elucidation and selective detection down to 30 ppb under SRM conditions. 

Tandem MS using the CID of the molecular ions further enhanced the specificity providing structure elucidation and selective detection down to 30 ppb. Liquid chromatography-ionspray-mass spectrometry has also been successfully applied for the assay of 21 sulfonamides in salmon flesh. Coupling of LC with either ISP-MS or ISP-MS-MS has also been investigated as an attractive alternative for the determination of erythromycin A and its metabolites in salmon tissue. The combination of these methods permitted the identification of a number of degradation products and metabolites of erythromycin at the 10-50 ppb level. Tandem MS with CID has also been... 

In experiments where a higher degree of sensitivity and selectivity is required, fluorescence and mass-selective detectors have been applied. Picomole limits of detection offered by fluorescence makes it ideal for routine analysis requiring high sensitivity. Mass spectrometry has also proven to be both a sensitive and efficient way to identify numerous chlorophyll derivatives (unitf4.s). van Breemen et al. (1991) utilized both fast atom bombardment (FAB) and tandem mass spectrometry (MS/MS) for the structural characterization and mass determination of numerous deriva-... 

The specific site of modification was established by high performance tandem MS experiments. In this technique the 12C isotope peak for the molecular ion in the first mass spectrometer is selectively introduced into an inert gas collision cell where fragmentation is induced. The fragments are separated and detected in the second mass spectrometer (22). Collisionally induced dissociation (CID) provides abundant structural information from which the amino acid sequence for the peptide (22) or, in this case, modified peptide can be deduced. 

---