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nbsp; The quantitative evaluation of seven duplicate analyses is shown in Table 5.   Table� 5.� Reproducibility of the Quantitative Analysis by Peak Area Normalization of a Five Component Synthetic Mixture (Isocratic High Speed Separation) Compound �������� Normalized Peak Area������� Mean Mean s s % p-Xylene 9.8 9.8 9.6 9.8 9.8 9.6 9.7 0.10 1.1   Anisole 11.9 11.9 12.2 12.2 11.9 12.0 12.0 0.17 1.4   Nitrobenzene

are inappropriate or impractical. This type of detector does, however, have one particular area of application for which its characteristics make it particularly suitable and that is for monitoring the separation of polymers. This is because for those polymers containing more than six monomer units, the refractive index is proportional to polymer concentration and independent of its molecular weight. Consequently, quantitative estimation of each polymer mixture can be obtained by simple normalization of peak areas and no individual response factors are required. RI detectors have sensitivities of about 1 x 10-6 g/ml, a linear dynamic range of about 200 and a response index (r) lying between 0.97 and 1.03

, for one reason or another, all other detectors are inappropriate or impractical. However, the detector has one particular and unique area of application and that is in the separation and analysis of polymers. For those polymers that contain more than ten monomer units, the refractive index is directly proportional to the concentration of the polymer and is practically independent of the molecular weight. A quantitative analysis of a polymer mixture can, therefore, be obtained by the simple normalization of the peak areas in the chromatogram (there being no need for the use of individual response factors). Some typical specifications for the refractive index detector are as follows:- Typical Specifications for a Refractive Index� Detector ��� �� Sensitivity (benzene) 1x 10-6 g/ml Linear Dynamic Range 1 x 10-6 to 1 x 10-4 g/ml Response Index 0.97 - 1.03 A typical application of the RI detector is for