Derivatives decomposition

Stainless steel transfer lines leading from the effluent and of the column to the detector should not be used because they will promote derivative decomposition. Glass columns should be used instead. Tyrosine, serine, and threonine are easily decomposed on hot metal surfaces. 

Intramolecular cyclopropanation is used to advantage for the preparation of cyclopropa[h]/[c]pyridine derivatives. Decomposition of diazoacetamides 174 catalyzed by Rh2(55-MEPY)4 and Rh2(4S-MEOX)4 affords 175, the products of intramolecular carbenoid addition onto the C=C... 

Derivation Decomposition of carbonate at high temperature in presence of carbon, oxidation of barium nitrate. 

Derivation Decomposition of 1-naphthylamine-4,8-disulfonic acid by diazotization and acidifying with heat. 

Derivation Decomposition of sodium tungstate with hot sulfuric acid. 

The application of GC-MS in metabolomics is not trivial. Metabolites generally must be derivatized to form more volatile molecules. A critical point in this process is that these reactions represent ongoing processes and need time to reach a plateau. Hence, ample time should be allowed before subjecting tri-methylsilyl (TMS)-derivatized samples to GC-MS analysis (43). On the other hand, as indicated above, the stability of the derivatives themselves is also limited. Hence, it is not practical to prepare large numbers of samples in one step and then leave them in the autosampler for extended periods before analysis, as the potential risk for derivative decomposition to occur cannot easily be compensated for. 

Thermolysis of phenyl trihalomethylmercurys gives dihalocarbenes. This reaction works well when one of the halogens is bromine, or better, iodine. For the iodo derivatives, decomposition occurs at room temperature (10). The decomposition of phenyl trichloromethylmercury is best accomplished by the addition of iodide ion (11) which has a high affinity for mercury ion because both are soft. 

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