Measurement error, preparative chromatography

Statistical process control methods are applied to preparative chromatography for the case where cut points for the effluent fractions are determined by on-line species-specific detection (e.g., analytical chromatography). A simple, practical method is developed to maximize the yield of a desired component while maintaining a required level of product purity in the presence of measurement error and external disturbances. Relations are developed for determining tuning parameters such as the regulatory system gain. 

Summary. Methods for determining the aqueous solubilities of PAHs are subject to errors associated with the preparation, extraction, and quantitative analysis of saturated solutions. There is no one method that has addressed the problems associated with each of these processes. Systematic errors associated with quantitative analyses of saturated solutions should be reduced in methods where selective analytical measurement techniques are used. Chromatographic methods allow separation of nonanalyte signals-in-time from those of the analyte. Fluorescence spectroscopy allows greater selectivity than UV spectroscopy, though less than gas or liquid chromatography. 

The sample preparation has been carried out at ambient pressure and temperature. The properties of the PEP-polymers used for the cloud-point measurements are listed in Table 8.1, for which the molecular weights have been measured with high temperature gel permeation chromatography (GPC, dynamic viscosity). The estimated relative error in the amounts of the components in the mixtures is <2% for PEP8.7, <0.1% for PEP51 and ethylene, and <0.7% for CO2. 

---