Discriminating solute property detectors

Current IPC detectors are on-stream monitors. HPLC detectors range from (1) non selective or universal (bulk property detectors such as the refractive index (RI) detector), characterized by limited sensitivity, (2) selective (discriminating solute property detectors such as UV-Vis detectors) to (3) specific (specific solute property detectors such as fluorescence detectors). Traditional detection techniques are based on analyte architecture that gives rise to high absorbance, fluorescence, or electrochemical activity. Mass spectrometry (MS) and evaporative light scattering detectors (ELSDs), can be considered universal types in their own right... 

Solute property detectors, such as spectroscopic andj electrochemical detectors, respond to a physical or chemical] property characteristic of the solute which, ideally, is] independent of the mobile phase. Althou this criterion is rarely met in practice, the signal discrimination is usually sufficient to permit operation with solvent changes (e.g., flow programming, gradient elution, etc.) and to provide high sensitivity with aj wide linear response range. Table 5.4. Solute-specific detectors complement ulk property detectors as they provide high ... 

Solute-property detectors. They critically respond to a particular physical or chemical characteristic of the solute (in question), which should be ideally and absolutely independent of the mobile-phase being used. But complete independence of the mobile-phase is hardly to be seen, however, signal discrimination is good enough to enable distinctly measurable experimental procedures with solvent changes, such as gradient-elution. 

Linearity of Response—For quantitative accuracy, detector re nse must be proportional to the mass of hydrocarbon injected, and the response of the non-normal paraffins is assumed to be equivalent to the response of the /i-paraffin with the same carbon number. In addition, sample injection technique and sample solution properties must be such that representative sample is intr uced to the gas chromatograph without discrimination. Before use, the analysis system must be shown to conform to these requirements as specified in 9.6.1. 

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