Date of Award
Master of Science in Engineering Science- (M.S.)
Chemical Engineering and Chemistry
Joseph W. Bozzelli
Relative Responses and Calibration Factors were developed for several volatile organic (mostly chlorinated) priority pollutant species in order to use one single stable compound (e.g.Benzene) for daily instrument calibration. This would replace the procedure of using a standard mixture of target compounds (25-35). This is of particular advantage because the standard mixture may not have all species stable or may show loss of some components relative to others due to wall adsorption in the standard (compressed gas) stainless steel cylinder.
The use of a single standard species was made possible by developing "accurate" relative response and calibration factors of all target compounds relative to Benzene in this case. The response and calibration factors were obtained by injecting the targeted compounds for both vapor and liquid standards into the GC and then analysing and comparing the results for accuracy and precision.
Results from this analysis showed that this is a viable and even preferential way to standardize the GC for routine quantitative analysis of a number of organic species. Liquid injection is the most acceptable method for determining relative response factors and calibration factors of compounds with boiling temperature above 60 C. Results from gaseous mixture of species shows low accuracy for compounds with boiling temperature above 110 C. These results for high boiling point vapors were all low and probably due to a combination of wall absorption, reaction with stainless steel tubing and cylinder and incomplete transfer of compounds into the vapor standard cylinder.
When developing calibration factors we obtained a linearity for the RRF's of these compounds with positive slope showing response enhancement for chlorine substituted compounds on FI detector at standard conditions. This is in contrast with previous investigators studies which employed older detector designs. Recent engineering improvement (1970 to present) in FI detector design and geometry with optimized combustion, flow velocities, improved electrodes (for ion collection) may account for the differences.
Jabalameli, Nahid, "Calibration of flame ionization detector for chlorinated hydrocarbons" (1984). Theses. 2178.