Relative volatility approximation test

Method 1 was recommended by Maddox (26,27) method 2 was recommended by Van Winkle (28), method 4 or 5 was recommended by Fair (29), Seader and Kurtyka (30), and McCormick and Roche (13), method 3 or 4 was preferred by King (9), while method 4 was preferred by a number of designers (11,31-33). Douglas (34) proposed a criterion for testing the relative volatility approximation. 

In approximate distillation column calculations, the relative volatility is sometimes assumed to be a constant (independent of composition, temperature, and pressure). Test this assumption for the ethanol-ethyl acetate system using the following data ... 

A fermented-egg product (EEP), patented as an attractive bait for synanthropic flies, has been shown to be attractive to coyotes and repeUent to deer (79). Its components are variable, with relative concentrations of 77% fatty acids, 13% bases, and 10% (primarily) neutrals composed of at least 54 volatiles such as ethyl esters, dimethyl disulfide, and 2-mercaptoethanol. Synthetic formulations have been evaluated to find a replacement for a patented fermented-egg protein product that attracts coyotes and repels deer. Ten aUphatic acids (C-2 to C-8), four amines (pentyl, hexyl, heptyl, and trimethyl), dimethyl disulfide, 2-mercaptoethanol, and 54 more volatiles (C-1 to C-5 esters of C-1 to C-8 acids) have been tested as synthetic fermented egg (SEE) (80) in approximately the same proportions that are present in EEP. Weathering was a problem that caused decreased efficacy, which suggests trials of controUed-release formulations. Eourteen repeUents have been examined against white-taU deer in Peimsylvania in choice tests when treated onto sheUed com (81). 

Respiratory Effects. Pleural effusions and alveolar infiltrations were noted in a man who had washed his hair with an unknown amount of diesel fuel (Barrientos et al. 1977). The relative contributions from inhalation and dermal exposure could not be distinguished in this case. There was no throat irritation in six volunteers following a 15-minute exposure to a concentration reported to be 140 mg/m of deodorized kerosene vapor (Carpenter et al. 1976). The authors used a hot nichrome wire for the volatilization of their test material and reported that the concentration was probably the "highest attainable concentration at which vapor analysis is representative of liquid analysis." The air saturating concentration of kerosene is considered to approximate 100 mg/m (room temperature and 760 mmHg) and is dependent on the constituents of the mixture. 

The objective was to transfer extracted volatiles from the SPME fiber to the MS in a relatively short time period, rather than waiting approximately 1 hour for a high-resolution chromatographic run. With this approach, more samples per hour can be tested. If a sample with unacceptable shelf life is discovered and more details about specific volatiles are desired, the sample can easily be retested to improve peak resolution by using a column temperature sequence that starts at a lower temperature (e.g., 50°C) and uses more gradual temperature ramps. The same analytical column can be used for both approaches, so no time is lost to column changeover and MS shutdown. 

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