Detection Diesel

Mld-IR sensor systems can be used onsite for the determination of organic pollutants in soils, aquifers, and marine environments. For Instance, Sanghera et al. deployed (Fig. 7.15] a 20 m long fiber combined with a portable FTIR unit and a cone penetrometer to detect diesel fuel contamination in soils and marine sands [167]. 

The first methanol bus in the world was placed in revenue service in Auckland, New Zealand in June 1981. It was a Mercedes O 305 city bus using the M 407 hGO methanol engine. This vehicle operated in revenue service for several years with mixed results. Fuel economy on an equivalent energy basis ranged from 6 to 17% mote than diesel fuel economy. Power and torque matched the diesel engine and drivers could not detect a difference. ReHabiUty and durabihty of components was a problem. Additional demonstrations took place in Berlin, Germany and in Pretoria, South Africa, both in 1982. 

NMOR is a potent hepatocarcinogen in the rat and induces tracheal and nasal cavity tumors in the Syrian golden hamster (43, 44, 45). It is formed readily from nitrite and morpholine in vitro and administration of these precursors to rodents causes tumors indicative of NMOR formation in vivo (44, 55, 56), NMOR has been detected in crankcase emissions of diesel engines and in factories engaged in rubber and tire manufacturing (57, 58). 

Because process mixtures are complex, specialized detectors may substitute for separation efficiency. One specialized detector is the array amperometric detector, which allows selective detection of electrochemically active compounds.23 Electrochemical array detectors are discussed in greater detail in Chapter 5. Many pharmaceutical compounds are chiral, so a detector capable of determining optical purity would be extremely useful in monitoring synthetic reactions. A double-beam circular dichroism detector using a laser as the source was used for the selective detection of chiral cobalt compounds.24 The double-beam, single-source construction reduces the limitations of flicker noise. Chemiluminescence of an ozonized mixture was used as the principle for a sulfur-selective detector used to analyze pesticides, proteins, and blood thiols from rat plasma.25 Chemiluminescence using bis (2,4, 6-trichlorophenyl) oxalate was used for the selective detection of catalytically reduced nitrated polycyclic aromatic hydrocarbons from diesel exhaust.26... 

Desulfurization using purified enzymes Investigations into enzymatic desulfurization as an alternative to microbial desulfurization has revealed several enzymes capable of the initial oxidation of sulfur. A study reported use of laccase with azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) as a mediator for oxidation of DBT [181]. The rate of this reaction was compared to hydrogen peroxide-based phosphotungstic acid-catalyzed oxidation and the latter was found to be about two orders of magnitude higher. The authors also oxidized diesel oil sulfur to no detectable levels via extraction of the oxidized sulfur compounds from diesel. In Table 9, the enzymes used in oxidation of DBT to DBTO are reported. 

Nitro polycyclic aromatic hydrocarbons are environmental contaminants which have been detected in airborne particulates, coal fly ash, diesel emission and carbon black photocopier toners. These compounds are metabolized Tn vitro to genotoxic agents through ring oxidation and/or nitroreduction. The details of these metabolic pathways are considered using 4-nitrobiphenyl, 1- and 2-nitronaphthalene, 5-nitro-acenaphthene, 7-nitrobenz[a]anthracene, 6-nitro-chrysene, 1-nitropyrene, 1,3-, 1,6- and 1,8-dinitro-pyrene, and 1-, 3- and 6-nitrobenzo[a] pyrene as examples ... 

A wide variety of nitro PAHs have been isolated from different environmental sources including airborne particulates (27-34), coal fly ash (35-37), diesel emission particulates (38-41) and carbon black photocopier toners (42-43). Their presence has also been suggested in the smoke from nitrate-fortified cigarettes (44). The structures of the most commonly detected nitro PAHs are shown in Figure 1 and in each instance it is the kinetically-favored isomer that is found. 

Selection of on-site analytical techniques involves evaluation of many factors including the specific objectives of this work. Numerous instrumental techniques, GC, GC-MS, GC-MS-TEA, HPLC, HPLC-MS-MS, IR, FTIR, Raman, GC-FTIR, NMR, IMS, HPLC-UV-IMS, TOF, IC, CE, etc., have been employed for their laboratory-based determination. Most, however, do not meet on-site analysis criteria, (i.e., are not transportable or truly field portable, are incapable of analyzing the entire suite of analytes, cannot detect multiple analytes compounded with environmental constituents, or have low selectivity and sensitivity). Therefore, there exists no single technique that can detect all the compounds and there are only a few techniques exist that can be fielded. The most favored, portable, hand-held instrumental technique is ion mobility spectrometry (IMS), but limitations in that only a small subset of compounds, the inherent difficulty with numerous false positives (e.g., diesel fumes, etc.), and the length of time it takes to clear the IMS back to background are just two of its many drawbacks. 

The total petroleum hydrocarbons represents a summation of all the hydrocarbon compounds that may be present (and detected) in a soil sample. Because of differences in product composition between, for example, gasoline and diesel, or fresh versus weathered fuels, the types of compounds present at one site may be completely different from those present at another. 

Source Componnds detected in major formulations and products are included, e.g., benzene detected in air, water, or soil samples may be related or have originated from various types of petroleum spills such as gasoline or diesel fuel. In some instances, the compound of concern may be an impurity in the material released to the enviromnent or it may be naturally present in various types of vegetation. 

Source Detected in groundwater beneath a former coal gasification plant in Seattle, WA at a concentration of 180 g/L (ASTR, 1995). Acenaphthene is present in tobacco smoke, asphalt, combustion of aromatic fuels containing pyridine (quoted, Verschueren, 1983). Acenaphthene was detected in asphalt fumes at an average concentration of 18.65 ng/m (Wang et al., 2001). Present in diesel fuel and corresponding aqueous phase (distilled water) at concentrations of 100 to 600 mg/L and 4 to 14 g/L, respectively (Lee et al, 1992). 

Acenaphthene was detected in a diesel-powered medium duty truck exhaust at an emission rate of 19.3 pg/km (Schauer et ah, 1999) and is a component in cigarette smoke. Acenaphthene was detected In soot generated from underventilated combustion of natural gas doped with 3 mole % toluene (Tolocka and Miller, 1995). 

Acetone was detected in diesel fuel at a concentration of 22,000 pg/g (Schauer et al., 1999). Identified as an oxidative degradation product in the headspace of a used engine oil (10-30W) after 4,080 miles (Levermore et al., 2001). Acetone also was detected in automobile exhaust at concentrations ranging from 0.09 to 4.50 mg/m (Grimaldi et al, 1996) and in cigarette smoke at concentrations ranging from 498 to 869 mg/m (Euler et al., 1996). 

Source Concentrations in 8 diesel fuels ranged from 0.026 to 40 mg/L with a mean value of 6.275 mg/L (Westerholm and Li, 1994). Lee et al. (1992) reported concentration ranges of 100-300 mg/L and 0.04-2 pg/L in diesel fuel and corresponding aqueous phase (distilled water), respectively. Schauer et al. (1999) reported anthracene in diesel fuel at a concentration of 5 pg/g and in a diesel-powered medium-duty truck exhaust at an emission rate of 12.5 pg/km. Anthracene was detected in a distilled water-soluble fraction of used motor oil at concentrations ranging from 1.1 to 1.3 pg/L (Chen et al., 1994). 

Source Detected in distilled water-soluble fractions of 87 octane gasoline (24.0 mg/L), 94 octane gasoline (80.7 mg/L), Gasohol (32.3 mg/L), No. 2 fuel oil (0.50 mg/L), jet fuel A (0.23 mg/L), diesel fuel (0.28 mg/L), militaryjet fuel JP-4 (17.6 mg/L) (Potter, 1996), new motor oil (0.37-0.40 jg/L), and used motor oil (195-198 Jg/L) (Chen et ah, 1994). Diesel fuel obtained from a service station in Schlieren, Switzerland contained benzene at a concentration of 76 mg/L (Schluep et al, 2001). The average volume percent and estimated mole fraction in American Petroleum Institute PS-6 gasoline were 2.082 and 0.2969, respectively (Poulsen et al, 1992). Schauer et al. (1999) reported benzene in a diesel-powered medium-duty truck exhaust at an emission rate of 2,740 pg/km. 

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