Partially validated methods, availability

Availability of Either Fully or Partially Validated Methods... 

Multitarget forensic applications of HPLC for other drug classes are also available in the literature. Josefsson et al. [77] applied HPLC-MS-MS to the determination of 19 neuroleptics and their major metabolites in human tissues and body fluids. Optimal separation was achieved using a cyano column within a 9 min gradient run. Detection was curried out in SRM reaching LQDs down to the lower ng/mL level, although more than a 10-fold difference in signal response was observed between analytes. The method was subjected to partial validation only. 

An orthogonal collocation method for elliptic partial differential equations is presented and used to solve the equations resulting from a two-phase two-dimensional description of a packed bed. Comparisons are made between the computational results and experimental results obtained from earlier work. Some qualitative discrimination between rival correlations for the two-phase model parameters is possible on the basis of these comparisons. The validity of the numerical method is shown by applying it to a one-phase packed-bed model for which an analytical solution is available problems arising from a discontinuity in the wall boundary condition and from the semi-infinite domain of the differential operator are discussed. 

There are samples or crude extracts containing the analyte of interest but whose concentration has not been accurately established. For marine biotoxins, such materials may be frozen homogenates of naturally contaminated seafood, crude or partially purified extracts of such seafood, or of harmful algae. Digestive glands of contaminated shellfish are a source of concentrated toxins and their metabolites. Such materials cannot be used to calibrate methods of analysis but can serve very useful functions in method validation and quality control, especially when they contain rare toxins not readily available elsewhere (i) Retention times and spectral properties can be established on a routine basis for LC-UV, LC-FL, or LC-MS methods (ii) Partially purified extracts can be used for fortification experiments during method validation and thus establish recovery and precision data (iii) If concentrations of toxins can be established by reference to CRMs, then the materials can be used as in-house or interlaboratory reference materials for quality control. Issues such as toxin stability and homogeneity then become more important. ... 

The experimental data collected by the acoustic method with the neoprene latex provided an opportunity to check the validity of the ECAH theory when thermal losses were the dominant mechanism of the sound attenuation (see Fig. 18). In order to calculate the theoretical attenuation spectra, information is required about the particle size, thermodynamic properties of the dispersed phase, and dispersion medium materials as well as partial intrinsic attenuations. Fortunately, all of the required parameters are available in this case. The approximate thermodynamic properties of the neoprene are known from the independent investigation performed by DuPont. 

All partial digestions suffer from a lack of standardized methods and recognized reference materials that can be used to validate decomposition and analytical protocols. Where standards are available, care must be taken to follow the precise leach protocol described in the reference certificate. 

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