Hydrocarbons analysis

Apparent indicator constant 264, 267 Apparent stability constant 59 Aqua regia 111 Arc alternating current, 764 direct current, 763, 771 sensitivities of elements, (T), 766 Aromatic hydrocarbons analysis of binary mixtures, 715 Arsenates, D. of (ti) 357 Arsenic, D. of as silver arsenate, (ti) 357 as trisulphide, (g) 448 by iodine, (am) 634, (ti) 397 by molybdenum blue method, (s) 681 by potassium bromate, (ti) 406 by potassium iodate, (ti) 401 in presence of antimony, (s) 724 Arsenic(III) oxide as primary standard, 261... 

No impurity peak that has a retention time greater than Lindane will have a peak height greater than that produced by 10 pg/mL Heptachlorepoxide (ECD) and 5 pg/mL Parathion (NPD). Hydrocarbon analysis... 

Gasoline Range Condensate Hydrocarbon Analysis in Relative Percent... 

Durham RW, Oliver BG. 1983. History of Lake Ontario (Canada, USA) contamination from the Niagara river by sediment radiodating and chlorinated hydrocarbon analysis. Journal of Great Lakes Research 9(2) 160-168. 

There are two noncolumn cleanup methods, one of which uses acid partition (EPA SW-846 3650) to separate the base/neutral and acid components by adjusting pH. This method is often used before alumina column cleanup to remove acid components. The other method (EPA SW-846 3660) is used for sulfur removal and uses copper, mercury, and tetrabutylammonium sulfite as desulfurization compounds. Sulfur is a common interfering compound for petroleum hydrocarbon analysis, particularly for sediments. Sulfur-containing compounds are very common in crude oil and heavy fuel oil. Elemental sulfur is often present in anaerobically biodegraded fuels. Thus, abnormally high levels of sulfur may be... 

Furthermore, as a fuel evaporates or biodegrades, its pattern can change so radically that identification becomes difficult. Consequently, a gas chromatographic fingerprint is not a conclusive diagnostic tool. The methods used for total petroleum hydrocarbon analysis must stress calibration and quality control, whereas pattern recognition methods stress detail and comparability. 

The quality of the analysis of polynuclear aromatic hydrocarbons is often dependent on the extraction efficiency. Clay and other cohesive soils lower the ability to extract polynuclear aromatic hydrocarbons. Another potential problem with polynuclear aromatic hydrocarbon analysis is that the test kits may have different responses for different compounds. 

Hemighaus, G. 1998. In Manual on Hydrocarbon Analysis, 6th ed., A. W. Drews (Ed.). American Society for Testing and Materials, West Conshohocken, PA, Chap. 3. 

FI mass spectra are normally characterized by intense molecular ion peaks accompanied by no or at least few fragment ions. [7,11,12] Especially in case of unpolar low-mass analytes, FI-MS can serve as molecular ion mass spectrometry (Fig. 8.10). [56] This property made Fl-MS become a standard tool for hydrocarbon analysis in the petroleum industry. [6,9,10,13,26,56-58]... 

McEwen, D. J. Automobile exhaust hydrocarbon analysis by gas chromatography. Anal. Chem. 38 1047-1053, 1966. 

J. C. Edwards and P. J. Giammatteo, Detailed hydrocarbon analysis of naphtha by on-line NMR integration of real-time NMR Feed analysis with advanced process control and optimization, Presented at Eastern Analytical Symposium, Somerset, NJ, November 18-21, 2002. 

Mass Spectrometry. The use of a quadrupole mass spectrometer as a GC detector for nonmethane hydrocarbon analysis has come of age in recent years. Development of capillary columns with low carrier gas flows has greatly facilitated the interfacing of the GC and mass spectrometer (MS). The entire capillary column effluent can be dumped directly into the MS ion source to maximize system sensitivity. GC-MS detection limits are compound-specific but in most cases are similar to those of the flame ionization detector. Quantitation with a mass spectrometer as detector requires individual species calibration curves. However, the NMOC response pattern as represented by a GC-MS total ion chromatogram is usually very similar to the equivalent FID chromatogram. Consequently, the MS detector can... 

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