Applications In Environmental Analysis

Examples of environmental analysis of amines in air are shown in Table 11.15. Air pollution is a important problem for public health. For air analysis, the National Institute for Occupational Safety and Health specifies exposure limits163 for amines in industrial air (10 to 30 ng ml) and for amines in indoor air (10 to 300 pg ml). The direct SPME could be used to monitor the amounts of the amines extracted from air in the following order Carbowax divinylbenzene CAX(DAB) > poly(acrylate) PA...

Ix

(c) 2nd dimension chromatograms FIGURE 3.25 The concept of multidimensional GC.26 (a) Single heart-cut GC analysis, in which a portion of the effluent from the primary column containing analytes of interest is diverted to the second dimension column and subjected to additional separation over an extended period of time. (b) Dual heart-cut GC analysis, in which two regions with coelutions are diverted to the second dimension column, with less time to perform each separation. (c) Comprehensive...

N

(NNK) figure 12.1 Structures of some nitrosamines. reactions. The optimum pH for the nitrosation of most secondary amines is between 2.5 and 3.5, depending on the pof the amine under consideration.7 Tertiary amines react with the nitrosating agents in an acidic aqueous solution to form A -nitrosamines but, in general, only after the complete formation of dialkylamines through dealkylation. In the presence of a nucleophilic anion such as I, Br, CI, SCN, acetate or phthalate, nitrous acid can be...

Ultrasonic Extraction USE

Ultrasound-assisted extraction is a solid-liquid leaching technique done in the batch mode. Solvent is added to samples before they are placed in a sonication bath. The procedure is usually repeated two or three times for quantitative extraction. Ultrasonication produces very localized, extremely high effective temperatures that increase extraction efficiencies of solvents, yet it is inexpensive and fast. Combined extracts are centrifuged or filtered, cleaned up, and concentrated by SPE or LLE...

Soxhlet Extraction

US EPA Method 3540 is for the Soxhlet extraction of nonvolatile and semivolatile organic pollutants from environmental solids and solid wastes.141 Solid samples are mixed with anhydrous sodium sulfate and placed in an extraction thimble inside a Soxhlet extraction apparatus. The Soxhlet apparatus allows the solvent to be distilled and recycled through the system thereby introducing fresh solvent with each cycle. Concentration and solvent exchange are usually required before analysis. Surrogate...

Info

Cadaverine

Figure 9.3 Total gas chromatogram obtained from standard heterocyclic amines containing 5 ng of each amine . GC conditions-peaks 1. 2-amino-9H-pyrido 2,3-b indole AaC 2-aminodipyrido 1,2-a 3 7 -d imidazole Glu-p-2 2. Glu-P-1 3. Trp-P-1 4. 3-amino-1-methyl-5H-pyrido 3,4-b indole Trp-P-2 5. IQ 6. MelQ 7. MelQx 8. 4,8-DiMeIQx 9. PhIP 10. 4,7,8-TriMeIQx . Reproduced with permission from Kataoka, H. and Kijima, K. J. Chromatogr. A, 767, 187-194, 1997. Copyright 1997, Elsevier Science. procedure...

References

P., Gillam, A. H., Gilbert, T. D., and Tate, K. R., Comparison of structures of humic substances from aquatic and terrestrial sources by pyrolysis-gas chromatography-mass spectroscopy, Geochim. Cosmochim. Acta, 47, 497-502, 1983. 2. Gadel, F. and Bruchet, A., Application of pyrolysis-gas chromatography-mass spectroscopy to the characterization of humic substances resulting from decay of aquatic plants in sediments and waters, Water Res., 21, 1195-1206, 1987. 3....

Amines And Nitrosamines

Extensive research has been done on the determination of amines including aromatic, aliphatic, alkyl, poly, glyco, biogenic amines and nitrosamines by various chromatographic methods in which many applications are based on the derivatization procedures adopted through different detection systems. The determination of aromatic amines has been carried out by capillary zone electrophoresis CZE , High-performance Liquid chromatography HPLC , GC, or GC-mass spectrometry with selected ion monitoring...

Undergoes Violent Collapse

Microjet Cavitation

FIGURE 2.29 Development and collapse of cavitation bubbles. Reprinted from Mason, T. J., Sonochemistry, Oxford University Press, Oxford, 1999. With permission. The most significant experimental variables are119 External applied pressure The formation of cavitation bubbles decreases with increasing ultrasonic frequency. A simple qualitative explanation of this effect could be that, at very high frequency the rarefaction and compression cycle is extremely short and the formation of a cavity in...

Oh

Figure 8.2 a Polysaccharides Predominant pyrolysis fragments from polysaccharides include furan and pyran derived structures. Other common pyrolysis products also include pyranosides and cyclopentenes and alkyl derivatives. b Proteins and nucleic acids Predominant pyrolysis fragments characteristic of proteins and nucleic acids include the nitrogen containing aromatic products such as pyrroles and pyridines and their alkyl derivatives. c Lipids Lipids undergo thermally catalyzed cyclization...

Ammonia

Ammonia is principally manufactured by direct synthesis from nitrogen and hydrogen using promoted iron catalysts, although it is also obtained commercially cheaply as a byproduct in the manufacture of coke and gas from coal. Ammonia is largely used in agriculture as fertilizer e.g., ammonia and solutions, ammonium nitrate, ammonium sulfate, ammonium phosphates, urea , in the production of nitric acid by oxidation of anhydrous NH3 , in the lead chamber process for manufacturing sulfuric acid, in...

Experimental Conditions Required for NO2 or NO Analysis

Porapak Hydrogen Nitrogen

Fluropak-80, 10 SF-96 at 250 Carrier Scavenger Pulse internal Detector temperature Sample size Retention time 0.5 ml, 5.0 ml 02, 1.6 min NO, 1.6 min NO2, 2.3 min Reproduced with permission from Chromatography of Environmental Hazards. Copyright 1973, Elsevier Science. column, or preferentially by direct injection of NO2. Tables 9.4 and 9.5 give the experimental conditions required for NO and NOX analysis. Phillips and Coyne108 separated NO and NO2 in a variety of nitrogen...

Iii

Figure 10.10 GC-NICI-MS and GC-EI-MS ion currents SIM mode for components with molecular mass of 258 and corresponding sulfur-selective GC-AED chromatogram. From Becker, G., Nilsson, U., Colmsjo, A., and Ostman, C., J. Chromatogr. A, 825, 57-66, 1998. figure 10.10 GC-NICI-MS and GC-EI-MS ion currents SIM mode for components with molecular mass of 258 and corresponding sulfur-selective GC-AED chromatogram. From Becker, G., Nilsson, U., Colmsjo, A., and Ostman, C., J. Chromatogr. A, 825, 57-66,...

Sample Preparation

There are basically two methods used for the analysis of A -nitrosamines in water samples. Those are liquid-liquid extraction using an organic solvent, and adsorption onto a sorbent material. The most popular solvent is the dichloromethane DCM for two reasons the volatile nitrosamines are highly soluble in this solvent, and the boiling point of the DCM is low, hence preventing the volatilization or the degradation of nitrosamines through a subsequent concentration step. In this extraction...

Electrospray ESI Figure 415

Esi Taylor

The electrospray process is initiated by applying an electrical potential of several kV to a liquid in a narrow bore capillary or electrospray needle. There are three major processes in ES-MS i Production of charged droplets at the ES capillary tip. A voltage of 2 to 3 kV is applied to the metal capillary. When the capillary is the positive electrode, source positive ions in the liquid will drift toward the liquid surface and some negative ions drift away from it until the imposed field inside...

Liu H Dasgupta P 1996 Analytical Chem 68 1817-1821

Valc rcel, M., Principios de Qu mica Anal tica, chaps. 4 and 7, Springer-Verlag Iberica, Berlin, pp. 175-239 and 337-365, 1999. 2. Grasselli, J. G., Undergraduate education in analytical chemistry level in the US-industrial needs 200, In Euroanalysis VII. Reviews on Analytical Chemistry, Malissa, H., Ed., Springer Verlag, Berlin, 1991. 3. Grasselli, J. G., The Analytical Approach, American Chemical Society, Washington, 1983. 4. Liu, H. and Dasgupta, P. K., Analytical chemistry in a drop....

Refrigerant

Focussed Microwave Assisted Extraction

FIGURE 2.27 Focused microwave-assisted Soxhlet extractor. Reprinted fromLuque-Garcia, J. L. and Luque de Castro, M. D., Trends Anal. Chem., 22, 90-98, 2003. With permission from Elsevier. FIGURE 2.27 Focused microwave-assisted Soxhlet extractor. Reprinted fromLuque-Garcia, J. L. and Luque de Castro, M. D., Trends Anal. Chem., 22, 90-98, 2003. With permission from Elsevier. includes an orifice atbottom of the irradiation zone enabling connection of the cartridge compartment to the distillation...