Linear programming sensitivity analysis

Although cSFC shows relatively poor figures of merit (speed, sensitivity, detection dynamic range and sample capacity) as well as a limited application area, its applications tend to be unique. These include solutes that can be solvated with pure SCCO2 and quantified with FID. Linear density programs typical in cSFC are ideal for homologous series found in surfactants, many prepolymers, etc. Selectivity in cSFC, which can be achieved by mobile phase density and temperature programming, relies on selective interactions with the stationary phase. Quantitative analysis in cSFC may be rendered difficult by small injected volumes the use of internal standards is recommended. 

Experimental work has shown that the analysis of quartz in respirable dust by Infrared spectroscopy using a Multiple Internal Reflectance Accessory is a viable technique that is sensitive, accurate and simple to perform. Linearity of a calibration curve from 0 to 200 micrograms has been demonstrated. A detection limit of approximately ten micrograms of quartz was obtained. An accuracy of + 35% at a 95% confidence level was demonstrated by data obtained from participation in the NIOSH PAT Program. 

Solute property detectors, such as spectrophotometric detectors, respond to a physical or chemical property characteristic of the solute, which is ideally independent of the mobile phase. Although this criterion is rarely met in practice, the signal discrimination is usually sufficient to permit operation with solvent changes (e.g. flow and composition programming) and to provide high sensitivity with a wide linear response range. For the analysis of complex mixtures with the modest plate numbers characteristic of... 

Fonr instrnments were deployed in unmanned sites, where they monitored VOCs in natural waters and wastewater during a period exceeding one year for each instrument The instruments were equipped with software that facilitated the automatic operation of each analysis, the identification and quantitation of VOCs from the raw mass spectra, and the transmission of the results to a remote control room via internet connection. In the remote control room, a personal computer with dedicated software displayed the results as bar graphs and was programed to activate alarms when set concentration thresholds were exceeded. Laboratory performance in terms of sensitivity, reproducibility, linearity tests, and comparison with P T/GC/MS together with field performance in terms of data output, most frequent maintenance operations and technical failures, and overall stability of the four remotely-controlled instruments are discussed. 

According to Hummel et al. [854], who described linear temperature-programmed pyrolysis of several thermo-resistant polymers (Twaron, Kapton and Py-rolin PI-2555) using FTIR with a heatable cell and LVEIMS (18 eV) for evolved gas analysis, FTIR is superior for the analysis of light fragments, whereas EIMS is more sensitive than FTIR. PyFTIR has mainly been used in the 80s and now appears to be declining. 

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