Mass-integration approach

Because of the complexity of these questions, the solution approach will be presented in stages. A systematic method for in-plant interception using MSAs is presented in the next section. Later, interception will be integrated with the other mass-integration strategies. 

Wilson et al. [662-665] have described various prototype systems for total organic analysis devices. It has proved technically feasible to obtain UV, IR, NMR and MS spectra (together with atomic composition based on accurate mass determination) following RPLC separation. The fully integrated approach offers the benefit that one chromatographic run is required, thus ensuring that all of the spectrometers observe the same separation. Such multiple hyphenations might favour the analysis of complex mixtures for both confirmation of identity and structure determination (should this represent a cost-effective approach). Table 7.72 illustrates the main features of on-flow multiple LC hyphenation. 

Jewell, D.M., Ruberto, R.G., Seshadri, K.S., "Transferable Hydrogen in Coal Liquids An Integrated Approach", presented at the 26th Annual Conference on Mass Spectrometry and Allied Topics", A.S.M.S., St. Louis, M0., May 28, 1978. 

Rindgen, D., Cox, K., Clarke, N. and Korfmacher, W., An Integrated Approach to Metabolite Identification for the Drug Discovery Compound SCH 123 using the Triple Quadrupole, Ion Trap and Q-TOF Instruments, American Society for Mass Spectrometry 2000 Conference Abstract, Long Beach, CA, USA, 2000. 

Ball, G., Mian, S., Holding, R, Allibone, R.O., Lowe, J., Ali, S., Li, G., McCardle, S., Ellis, I.O., Creaser, C., and Rees, R.C., An integrated approach utilizing neural networks and SELDI mass spectrometry for classification of human tumours and rapid identification of potential biomarkers. Bioinformatics, 18, 395 04, 2002. 

Separation of dibenzothiophene derivatives from petroleum oil fractions has been achieved by integrated approaches in which fractionating processes such as isothermal distillation, vacuum fractionation, and molecular distillation have been combined with spectroscopic methods including mass spectrometry and NMR spectroscopy. " Dibenzothiophenes have also been concentrated in sharp chromatographic fractions obtained, for example, by, alumina gel percolation, and have been detected by gas chromatography. Gas chromatography has also been used to... 

The LTQ-FT mass spectrometer was introduced in late 2003 and, as expected, the main application discussed in the literature is for the analysis of proteins and peptides (Johnson et al., 2004 Syka et al., 2004). A recent book chapter (van der Greef et al., 2004) and a review article (Brown et al., 2005) discussed the application of the LTQ-FT to metabolomics. FTMS applications to dmg metabolism are still very new and dmg discovery research laboratories which have recently purchased the instmment are still in the process of developing and validating methods and approaches. A recent publication describes the depth and flexibility of the experimental setup utilizing accurate mass data-dependent exclusion MS" measurements with a LTQ-FT (Tozuka et al., 2005). We have reported several integrated approaches for determination of metabolic stability, characterization of metabolites and metabolic... 

The reactor system of Zech et al. [35] is a good example of an integrated approach as it combines devices from different suppliers into a complex screening system. The reactor was manufactured at IMM (Fig. 4.4) and the sampling device delivered by AMTEC in Chemnitz. The catalyst preparation method was developed at the TU Chemnitz. The latter consists of an x/y-positioning robot supervised by a CCD camera. The sampling capillary was connected to a quadmpole mass spectrometer. This set-up has been used to screen up to 35 catalysts a day. 

Due to the frequently observed chemical memory of a working catalyst, reproducible synthesis of the active mass with respect to all synthetic steps is a basic requirement. Moreover, an integrated approach requires the consideration of a catalyst as a hierarchical system taking into account mass transport and thermal conduction properties, as well as mechanical stability in the early stages of the development of synthetic concepts closing the cycle of rational catalyst design. 

Relations expressing the conservation of mass, momentum, and energy at an interface may be derived by writing equations (l)-(4) in integral form and then passing to the limit in which the volume of integration approaches a surface. 

In this chapter, emphasis is placed on the former approach of pinch technology. It is noteworthy that the mass integration concept incorporates the use of both approaches. Also, a notable work that combines the three approaches of hierarchical design via process simulation using the Aspen Plus commercial simulator, pinch technology, and mathematical programming is that of Dantus and High. ° ... 

Such phenomena dictated two major philosophies for our work with pyrethroids (a) a mass balance approach was taken to account for all losses in the experiments (b) as long as the pyrethroids maintained their chemical integrity (did not hydrolyse or otherwise degrade) then use of radiolabelled analytes was desirable. This allowed the low concentrations of the pyrethroids in the aqueous phase to be accurately and reproducibly determined and the mass balance to be computed. The chemical integrity of the radiochemicals was determined by radio-chromatographic techniques (radio-TLC and radio-HPLC). 

Ranasinghe, A. et al., Integrated approach to API quantitation and rapid in-vivo metabolic profiling in early discovery PK assays, in Proceedings of the 57th ASMS Conference on Mass Spectrometry and Allied Topics, ASMS, Philadelphia, PA, 2009. 

---