Sulfur hexafluoride sensitivity

Sulfur hexafluoride may be analyzed chromatographicaHy using a molecular sieve or a Porapak QS column. Using an electron-capture detector, a sensitivity of 10 to lO " ppb is possible (51—53). 

The flame ionization detector Is the most popular of the flame-based detectors. Apart from a reduction in sensitivity compared to expectations based on gas chromatographic response factors [138] and incompatibility with the high flow rates of conventional bore columns (4-5 mm I. 0.), the flame ionization detector is every bit as easy to use in SFC as it is in gas chromatography [148,149]. It shows virtually no response to carbon dioxide, nitrous oxide and sulfur hexafluoride mobile phases but is generally incompatible with other mobile phases and mixed mobile phases containing organic modifiers except for water and formic acid, other gas chromatographic detectors that have been used in SFC include the thermionic ionization detector (148,150], ... 

For a coulometric response, an ideal compound, sulfur hexafluoride, has remarkable sensitivity (10-1 g/sec). Again it should be emphasized that this value will be unique for a particular compound and depends on the species affinity for electron capture. 

Gas chromatography with ECD has also been used to detect carbon disulfide in air (Johnson and Bates 1993). In this system, carbon disulfide is separated by chromatography, converted to sulfur hexafluoride (SF6), and then detected by ECD. The ECD detector is 10-100 times more sensitive than the FPD detector and requires smaller sample volumes (Johnson and Bates 1993). 

In the use of an electronic leak detector method, a 2% mixture of sulfur hexafluoride in air is used as the test gas. Detector sensitivity is approximately the same as the detector mbe method of test. The presence of the radiation source in this detector, however, requires a special... 

The reaction rate, k, of liquid lithium with a number of gaseous oxidizers including sulfur hexafluoride, SFis and several halocarbons has been investigated in Ref. [7]. For perfluorocyclobutane, C4F8 k is sensitive to both temperature and pressure and is depicted below in Figure 5.2. The onset of the reaction is at 360 °C which... 

For amine regenerator reboilers, at Amoco Oil we used a commercially available leak detector kit. Sulfur hexafluoride was injected into the reboiler steam and the reboiler vapor outlet was then monitored for SF. The detector is sensitive to 1 ppb (billion). The commercially available unit I m familiar with is sold under the trademark of Huortracer Analyzer. Both the analyzer and a SF dispenser are needed. 

URANIUM HEXAFLUORIDE (7783-81-5) FjU Radioactive. Violent reaction with water, steam, ethanol, producing hydrogen fluoride gas. Violent reaction with alcohols, aromatic hydrocarbons (benzene, toluene, xylenes, etc.), bromine trifluoride. Aqueous solution increases the explosive sensitivity of nitromethane and is incompatible with sulfuric acid, alkalis, alcohols, ammonia, aliphatic amines, alkanolamines, alkylene oxides, amides, epichlorohydrin, ethers. 

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