Plasma sedimentation constant

Quite apart from the X-component, certain purified plasma globulin fractions—notably some a- and j3-globulins—have sedimentation constants (s,o) near 4.5 S, and are indistinguishable in this respect from albumin. ... 

Electrophoretic component Approximate concentration in plasma, g./lOO ml. Sedimentation constant, Sio Approximate molecular weight... 

Quantitative analysis usually requires the use of standards and/or certified reference materials (CRMs), the selection of an appropriate elemental optical emission line, and, in most cases, the selection of a normalization line, used as an IS. Calibration curves are then constructed using the normalized peak area versus concentration, as previously described for calibration using an IS. When there is a dominant matrix component for which the concentration will remain approximately constant across the calibration set, it is best to use an emission line from that matrix element for normalization. This approach helps minimize effects due to changes in plasma conditions caused by shot-to-shot fluctuations in laser intensity. Alternatively, chemometric correlation analysis of the entire observed spectrum with the concentration of the analyte can be used to construct calibration curves automatically. In general, RSDs of 5%-10% are readily achievable. To improve quantitation, sample preparation methods such as pressing pellets may improve results for soils and sediments and fusion with salts to convert the sample into a glass bead can eliminate matrix effects. Fusion was discussed in Chapter 1 and is used extensively in XRF analysis (Chapter 8). 

Determinations of sedimentation and diffusion constants, and of molecular weights, of purified plasma protein fractions are presented in Part VI. 

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