Chlorine, determination carriers

The methyl esters can be also determined by GC-FID. Using a 30 m x 0.32 mm ID x 0.25 pm (film thickness) capillary column, such as DB-1701 or equivalent, the compounds can be adequately separated and detected by FID. The recommended carrier gas (helium) flow rate is 35 cm/s, while that of the makeup gas (nitrogen) is 30 cm/min. All of the listed herbicides may be analyzed within 25 min. The oven temperature is programmed between 50 and 260°C, while the detector and injector temperatures should be 300 and 250°C, respectively. The herbicides may alternatively converted into their trimethylsilyl esters and analyzed by GC-FID under the same conditions. FID, however, gives a lower response as compared with ECD. The detection level ranges from 50 to 100 ng. For quantitation, either the external standard or the internal standard method may be applied. Any chlorinated compound stable under the above analytical conditions, which produces a sharp peak in the same RT range without coeluting with any analyte, may be used as an internal standard for GC-ECD analysis. U.S. EPA Method 8151 refers the use of 4,4,-dibromooctafluorobiphenyl and 1,4-dichlorobenzene as internal standards. The quantitation results are expressed as acid equivalent of esters. If pure chlorophenoxy acid neat compounds are esterified and used for calibration, the results would determine the actual concentrations of herbicides in the sample. Alternatively, if required, the herbicide acids can be stoichiometrically calculated as follows from the concentration of their methyl esters determined in the analysis ... 

The separation and determination of the chlorination products of alkylchlorosilanes, such as trichloroethylsilane or dichlorodimethylsilane, are effected on a column packed with PFMS-4 poly(methylphenylsiloxane) on Celite 545, with helium as carrier gas and katharometer detection401. The chlorination products of trichloromethylsilane are analysed on a column packed with SKTFT-50-siloxane rubber on TND-TS-M. 

A gas chromatographic method using a gas density balance detector has been described407 for the determination of chlorinated phenylchlorosilanes using a column packed with Celite 545 supporting 10% of Lukopren G 1000 (a silicone elastomer), with nitrogen as carrier gas. 

The amount of an evolved gas can be determined by a continuous titration method. A carrier gas removes the evolved gas from the furnace chamber and transports it to an aqueous-absorbing solution where it is continuously titrated. The titrant used will depend on the type of evolved gas to be determined. For example, ammonia is titrated with dilute hydrochloric acid, whereas water is determined by the Karl Fischer method. Compounds that can be determined include water, hydrogen chloride, ammonia, sulfur dioxide, carbon dioxide, and chlorine (80). 

Brazhnikov and Sakodynskii determined the retention time of boron trichloride on various supports and stationary phases and compared its behaviour to that of boronalkyls, Zelyaev et al used a molybdenum glass column packed with poly (methylsiloxane) on Spherchrom 1 to separate in amounts down to O.lppm of various trace impurities in boron trichloride, such as chlorine, phosgene, silicon tetrachloride, chloroform, carbon tetrachloride and dichloroethane. They used a column temperature of 60°C with nitrogen as carrier gas and employed thermionic and flame ionization detectors,... 

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