Quality control relative ratios

From a natural products standardization perspective, the HPLC profiles of three different batches of Nicosan are illustrated in Figure 3. Here, the HPLC patterns of the three batches are nearly identical as needed. The presence and/or absence and relative ratio and total content of selected targeted compounds are used in the standardization and quality control process. Some of the compounds present in the extract have been identified and are discussed more below. 

The use of ion ratios can also be useful for monitoring the quantity of unusual peaks relative to other peaks or standards. One example is EDTA, which is detectable in an AC profile. Calculation of a concentration for this marker is meaningless but an ion ratio to a standard could serve as a means to detect a significant concentration of this anticoagulant. Another use of an ion ratio is a quality control marker. For example the mass for an underivatized AC standard, that is, palmi-toylcarnitine, could be monitored relative to other AC standards. An ion ratio above a certain threshold could alert the user of a poor derivatization and reject a plate or specimen. 

Factor analysis had previously been used by Culler et al. [100] for quality control monitoring of a polymeric composite system of y-aminopropyl-triethoxysilane (j/-APS) coupling agent on an E-glass mat substrate. In this system, factor analysis successfully indicated the number of pure components, extracted the spectra of the pure components, indicated the relative concentrations of spectra, and improved the S/N ratio in the extracted spectra. The construction of a calibration curve allowed factor analysis to be used as a QC monitor of the amount of coupling agent on the E-glass mats. 

Sodium Adsorption Ratio. Because of the swelling effects of Na+, the relative amount of sodium (sodicity) in the water quality especially in the irrigation water quality is an important measurement in soil science. Decreased permeability can interfer with the drainage required for normal salinity control and with the normal water supply and aeration required for plant growth. The relative sodium status of irrigation waters and soil solutions is often expressed by the sodium adsorption ratio (SAR)... 

---