Selected targeted compound analysis

In target-compound analysis, a particular compound, usually present in a complex matrix and at trace levels, needs to be quantified. Here, selectivity and... 

Flavor chemists have traditionally relied on mass spectrometry in conjunction with gas chromatography (GC/MS) to identify the structures of volatile flavor components in heated food systems. Mass spectrometry provides the molecular weights of fragment ions, which are useful for deducing-molecular structure. The MS detection limit is on the order of 1CT g, however detection limits for target compound analysis or chemical class detection via selected ion monitoring can be much lower. Extensive libraries of mass spectra are available even so, many new flavor compounds can often not be identified from MS data alone. 

In this paper some important aspects of LC/MS in bioanalysis are discussed. In order to achieve best performance in thermospray LC/MS optimization of the various experimental parameters is necessary. As a result of systematic studies on the influence of the various parameters an optimization strategy is developed, which will be discussed. Two recent bioanalytical applications are discussed. The applications are concerned with confirmation and identification of compounds in biological matrices (qualitative aspects) and with target-compound analysis. The examples have been selected in order... 

High selectivity and low detection limits can be achieved by using direct ionisation of resonant analytes with a Nd YAG laser in an MPI-FTMS experiment. Multiphoton ionisation in combination with FTMS [237,238] has been used for both surface analysis [239] and as an efficient and selective ionisation source for GC-FTMS [240]. The rugged design of REMPI-ToFMS devices allows application for target-compound analysis under industrial... 

In routine analysis this evaluation is carried out for target compound analysis by the data system. If the information on the retention time of an analyte, the mass spectrum, the selective quantifying mass and a valid calibration are supplied, a chromatogram can be evaluated in a very short time for a large number of components (Figure 3.5, see also Section 3.3). 

Tam et al. [37-47] developed an impressive generalized method for the determination of ionization constants and molar absorptivity curves of individual species, using diode-array UV spectrophotometry, coupled to an automated pH titrator. Species selection was effected by target factor analysis. Multiprotic compounds with overlapping pK s have been investigated binary mixtures of ionizable compounds have been considered assessment of inicroconstants have been reported. 

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