Analytical Chemistry and Auto Emissions - American Chemical Society

Analytical Chemistry andAutoEmissions Dennis Schuetzle and Trescott E. Jensen Ford Motor Company Dearborn. Ml 48121

Donald Nagy and Arnold Prostak General Motors Corporation Milford, Ml 48380

Albert Hochhauser Exxon Research and Development Company Linden, NJ 07036

Although emissions from current gasoline-powered motor vehicles have been reduced significantly since the 1960s, these emissions still account for a significant fraction of the hydrocarbons (HC) and nitrogen oxides (NO^) emitted into ambient air. HC and NO^ react with sunlight to form ozone, a major component of photochemical smog (1, 2). Motor vehicles are also a source of carbon monoxide emissions and toxic air pollutants (5). Approaches to reducing vehicle emissions include the use of reformulated fuels, alternative fuels, improved catalysts, modified e n gines, and better electronic engine control strategies. Recent legislation h a s been enacted by the federal government and the state of California to require further reduction of vehicle emissions to improve air quality (4). In October 1989 the three domestic automobile companies and 14 petroleum companies established a cooperative r e search program, t h e Auto/Oil Air Quality Improvement Research Program (AQIRP). The goal of this program is to develop data regarding the potential reduction in total vehicle emissions and improvement in air quality that may result from the use of reformulated gasolines in existing vehicles, as well as the use of methanol fuel (e.g., 85% methanol/15% gasoline) in flexible-fueled (FFV) and 0003 - 2700/91 /0363 -1149A/$02.50/0 © 1991 American Chemical Society

variable-fueled (VFV) vehicles. By sharing resources, these organizations believed they would be better able to provide the technical expertise and state-of-the-art facilities to undertake such a complex research program in a short period of time. The specific research objectives of the Phase I program were to test 26 reformulated and two reference gasolines in 20 current (1989) and 14 older (1983—85) vehicles as well as two methanol blends (M10 and M85) and one industry-average fuel in 19 FFV or VFV passenger vehicles (5). These tests involved the collection and analysis of tailpipe exhaust and evaporative emissions during simulated city driving conditions. Detailed chemical speciation data were needed for modeling studies to predict the effect of fuels on air qual-

past 20 years to characterize vehicle emissions (7-12), none met the stringent requirements of this program. Analytical approach To satisfy the needs of this research program, analytical techniques must satisfy a number of requirements. They must be able to characterize the 0 , - 0 , 2 hydrocarbons and oxygenated hydrocarbons present in exhaust and evaporative emissions as well as in fuels and fuel blends. In addition, because emissions testing facilities typically used for measurement of regulated vehicle emissions (e.g., hydrocarbons, carbon monoxide, and nitrogen oxides) do not usually have the laboratory personnel or environment found in a research laboratory, t h e techniques required for this large workload need to be highly

ANALYTICAL APPROACH ity in major urban areas (such as Los Angeles, New York, and Dallas/Fort Worth). Analytical data were needed for more than 8000 samples over a nine-month period. The challenge to the analytical chemist was to develop highly automated and accurate procedures for the speciation of emissions t h a t could be carried out 24 hours a day with a high degree of reliability in vehicle testing facilities. Vehicle emissions originate from the complete and incomplete combustion of fuel, engine oil evaporation, engine oil combustion, and fuel evaporation. As a result, these emissions are composed of hundreds of gas and p a r t i c u l a t e - p h a s e o r g a n i c compounds in t h e part-per-trillion to part-per-million range (3, 6). Although numerous analytical techniques have been developed over the

automated, user friendly, and rugged enough for vehicle testing facilities. The methods used for the emissions measurements are summarized in the box on p. 1150 A. Flame ionization detection (FID), nondispersive IR, and chemiluminescence instruments have been used to measure emissions for more than 15 years. These techniques are typically accurate and reproducible to better than 10% for the measurement of emissions from current model vehicles (1989— 91). This program concentrated on the development of GC techniques for C]—C12 hydrocarbons, ethers, and alcohols, and on HPLC techniques for C,—C8 aldehydes and ketones. Several factors can influence the accuracy and reproducibility of vehicle emissions measurements. Important variables include those associ-

ANALYTICAL CHEMISTRY, VOL. 63, NO. 23, DECEMBER 1, 1991 • 1149 A

ANALYTICAL APPROACH ated with the test facility (vehicles, drivers, fuel consumption, dynamometers, environmental conditions, and contaminants in the background dilution air) as well as those associated with the analytical technique (losses/ reactions in the sampling system; instrument noise, detection limits, selectivity, and response time; and accuracy of reference materials and species identification). One of the objectives of the analytical development program was to perform studies that could be used to determine how these various sources of variability can influence the accuracy and precision of the speciation measurements. The testing program was designed and sized in terms of

the number of vehicles, number of tests, and the fuel matrix so t h a t valid statistical relationships could be derived between the composition of the fuel and emissions. It was necessary early in the program to establish requirements in terms of precision a n d a c c u r a c y . In a d d i t i o n , computer software was needed that could control the instrumentation, automatically identify and quantify chemical species, and compile data sets for the modeling studies. To produce reliable atmospheric modeling results, it was determined that individual species needed to be measured at the 0.05 ppm C level— approximately 1.0 mg/mi tailpipe Federal Test Procedure (FTP) com-

Methods used for emissions measurements Analyte

Method

Total hydrocarbons Carbon monoxide/carbon dioxide Methane Total nitrogen oxides 0 , - 0 , 2 hydrocarbons and ethers 0,-Ca aldehydes and ketones Alcohols

FID Nondispersive IR spectroscopy GO Chemiluminescence analysis GC LC of DNPH derivatives

GC

posite emission rate for C 3 species— with better than ±20% RSD for repetitive tests. The identified species should account for more than 85% of the total hydrocarbon mass emitted, and no more than 5% of the components at concentrations > 0.05 ppm should be misidentified. Emission sampling

The old adage in analytical chemistry that "the development of proper sampling methodologies is at least 50% of the task" is particularly true for vehicle emissions measurements because the laboratory tests must simulate real-world conditions as closely as possible. Three different testing protocols were necessary to account for all emissions. Figure 1 depicts the sampling techniques used for tailpipe, evaporative, and evaporative running loss emissions. Although one facility could be designed to accommodate all three types of tests as shown in the figure, three separate facilities were used in these studies to simplify the collection of each sample type. T a i l p i p e e m i s s i o n s . The most common vehicle exhaust emission test driving schedule used in the United States is the Environmental Protection Agency (EPA) Urban Dy-

Temperature and humidity-controlled testing enclosure

Running loss and evaporative emissions

Conditioned laboratory Exhaust

air

Tailpipe emissions

Air intake for engine

Engine-out emissions

Figure 1. Testing facility used for the sampling and analysis of exhaust, running loss, and evaporative emissions. 1150 A • ANALYTICAL CHEMISTRY, VOL. 63, NO. 23, DECEMBER 1, 1991

namometer Driving Schedule (UDDS), which is part of the FTP (13). This FTP driving schedule has three phases and was used in all of the AQIRP studies. The dynamometer shown in Figure 1 is used to simulate the load a vehicle would encounter under actual road driving conditions. The tailpipe emission samples were diluted about 15:1 or 30:1 with filtered, humiditycontrolled air for gasoline or methanol blends, respectively. Humiditycontrolled laboratory air was used to prevent condensation of water and to allow cooling. The diluted samples were collected in three Tedlar bags during the corresponding cold start, stabilized, and hot-start phases of the 31.3-min FTP schedule. Some chemical species may be lost as a result of surface adsorption (e.g., formaldehyde) and reactions of labile species (e.g., 1,3-butadiene). Contamination may enter from surfaces (e.g., silicones), and background air (e.g., fuel). Prevention of water condensation becomes more of a problem when methanol/gasoline m i x t u r e s are used, because methanol combustion produces twice as much water as that of gasoline. Water condensation was minimized by increased dilution of the exhaust sample and/or dehumidification of the diluent air. To minimize any losses in the Tedlar bags, the samples were normally analyzed within 4 h following collection. Time/stability studies demonstrated that there was negligible loss ofC i - C i o species during the first 4 h of collection. Even highly polar organic species such as methanol and formaldehyde showed good recovery (better than 90%) after storage in a Tedlar bag for up to 4 h (14). Evaporative emissions. Volatile hydrocarbons can also e v a p o r a t e from various noncombustion sources such as the fuel tank cap, fuel tank, fuel lines, carbon canister, and various fuel system seals. To measure such evaporative emissions, the vehicle was placed in an environmentally controlled chamber for prescribed periods of time and under specific environmental conditions, and the gas tank was heated as part of the testing protocol. "Grab" samples were taken at the start and end of the test using impingers or Tedlar bags. R u n n i n g loss e m i s s i o n s . Running loss emissions represent the evaporative loss of fuel during simulated driving conditions. The temperature of the fuel tank was controlled to simulate fuel t a n k temperature profiles obtained on the road, and a

point source method was developed for the measurement of vehicle running loss mass emissions. The technique required the design and fabrication of both the equipment to heat and cool the fuel system on the vehicle (to match the road temperature and pressure profiles for fuel in the tank) and the sample collection system for collecting vapors from specific "points" such as the charcoal canister fresh air vent, the fuel tank safety relief valve, and the fuel filler cap. The running loss test required that a test site be modified to enable the vehicle to be run on a chassis dynamometer at a test cell temperature of 95 °F. Extensive training of labor a t o r y personnel was required to match the road temperature profiles for the fuel system in the test cell environment on a precise and repeatable basis. Operational, calibration, and quality a s s u r a n c e procedures were also developed, because they were not available as part of the normal emissions certification testing protocol. Speciation of emissions

As shown in Figure 2, a variety of analytical techniques were developed for speciation of emissions. Most of the developmental work focused on the speciation of C 1 - C 1 2 hydrocarbons and ethers, C^-Cg aldehydes

and ketones, methanol, and ethanol. S p e c i a t i o n of h y d r o c a r b o n s a n d ethers. Most of the hydrocarbon mass emitted from gasoline-fueled vehicles consists of C j - C ^ hydrocarbons. When oxygen-containing fuel components, such as methyl tertbutyl ether (MTBE), ethyl fert-butyl ether (ETBE), or alcohols are used, the oxidation products of these components as well as the components themselves may also be present in emissions. Laboratory studies were undertaken to determine the detailed composition of the 26 reformulated and two reference gasolines. These fuels were found to contain about 200-300 different hydrocarbon species t h a t were present at concentrations > 0.01 wt %. A multiple-column GC approach has been used by the EPA, the California Air Resources Board (CARB), and other investigators (7-12) to adequately resolve these complex samples. However, a multiple-column approach was considered unacceptable for the Phase I program because several gas chromatographs would be required for the analysis of each sample, calibration and quality assurance procedures would be difficult to carry out, and data merging would be complex. In addition, a multitechnique approach would be too time-consuming to allow the

Hydrocarbon and ether emissions Tailpipe (Tedlar bags) Running loss GC (Tedlarbags) Evaporative (Tedlar bags) GC/MS Reference Blind validation materials standards

Data system

Qualitative/ quantitative standards

Fuel stocks/ fuel blends

Aldehyde and ketone emissions Tailpipe (impingers)

Data system

LC Reference Blind materials standards


Alcohol emissions Tailpipe (impingers) Running loss (impingers) Evaporative (impingers)

Data system

GC Reference Blind materials standards


Figure 2. Sample sources and analytical procedures for speciation of emissions. ANALYTICAL CHEMISTRY, VOL. 63, NO. 23, DECEMBER 1, 1991 • 1151 A

ANALYTICAL APPROACH analysis of 8000 samples in nine months. Although GC/MS was considered as a possible s i n g l e - a n a l y s i s a p proach, such a procedure would be costly and difficult to incorporate on a routine basis in vehicle emissions testing laboratories. In addition, a quantitative procedure using GC/MS would have required that a library of response factors be developed for each component, and daily calibra tion and quality control procedures would have been more complex. An optimized single-column GC analysis technique was therefore de veloped. It was necessary to carefully assess the trade-offs between com pound selectivity, detection limits, accuracy, precision, and the effect of these parameters on the accuracy of the modeling calculations. The analytical development stud ies focused on the GC and GC/MS characterization of various test fuels and emissions to help establish an understanding of the relationship be tween fuel composition and tailpipe emissions. Exhaust emissions from vehicles, single-cylinder engines, and flame pulsators were used to help generate samples in this effort (15). A GC reference library that consisted of 141 compounds (including paraf fins, olefins, alcohols, aldehydes, ethers, and aromatic hydrocarbons) was established over a period of about six months. Validation studies conducted before the initiation of the Phase I program demonstrated that these 141 compounds accounted for ~ 95% of the hydrocarbon mass in exhaust emissions. A 60-m χ 0.32-mm i.d. (1-μπι film) DB-1 capillary GC column was found to produce the optimum resolution for this library of compounds. A GC program that used a two-step linear temperature ramp (55-min total analysis time) was devised. All GC systems were equipped with split/ splitless injection and an automated gas sampling valve with a 2.0-mL sample loop maintained at 110 °C. The split was 5:1, which resulted in a sample injection volume of 0.4 mL. This single-column gas chromatograph yielded good separations for C 2 - C 4 hydrocarbon species, which have presented co-elution problems with some other columns and tem perature programs; n e a r - b a s e l i n e resolution of the C 2 hydrocarbons was observed. It was not expected that all signif icant species would be resolved in the single-column GC analysis of these chemically complex samples. There

were three important unresolved coeluting pairs: benzene/1 -methylcyclopentene, toluene/2,3,3-trimethyl p e n t a n e , a n d m-xylene/p-xylene. Further studies were required to de termine the importance of these coelutions on the atmospheric modeling results. GC/MS characterization was u n dertaken to determine the benzene/ 1-methylcyclopentene ratio in t h e exhaust and evaporative emission samples (16). Because 1-methylcyclo pentene is much easier to combust and catalytically oxidize than ben zene, only trace quantities of 1-me thylcyclopentene were found in the exhaust emissions, compared with benzene. In addition, benzene is formed in the engine via pyrosyn thetic and free radical processes. Therefore, the contribution of 1-me thylcyclopentene to the benzene peak was considered to be negligible in the tailpipe emission samples. The benzene/methylcyclopentene ratios in the evaporative (vapor phase) sam ples were found to be similar to their relative concentrations in the fuels, which is consistent with the similar boiling points of these species. The toluene concentration was cor rected by measuring the 2,3,4-trimethylpentane (234TMP) concentration and applying a correction factor. The fuel composition data showed that the 2 , 3 , 3 - t r i m e t h y l p e n t a n e (233TMP) concentration was close to t h a t of 234TMP. Because 233TMP and 234TMP have nearly equivalent chemical reactivities, it was assumed that the ratio of 233TMP to 234TMP would remain relatively constant in the emission samples. Thus the tolu

ene concentration was determined by measuring the toluene/233TMP and 234TMP peaks and applying the ap propriate corrections. The relative concentration of the xylene isomers was nearly constant in the 26 reformulated gasolines (m-xylene/^-xylene: 2.4/1.0). This ra tio was also found to be constant in the tailpipe and evaporative emission samples. One problem encountered in this development program was the short age of suitable computer hardware and software that could be used to effectively identify and quantify the 141 hydrocarbon species with a high degree of reliability and accuracy. A H e w l e t t - P a c k a r d Model 5890 gas c h r o m a t o g r a p h w i t h a dedicated computer system represented a good starting point for further develop ment. Additional software was devel oped to facilitate calibration, species identification, quantitation, and data reporting. Species identification was based on the comparison of retention times and retention index (RI) values. RI was calculated as RI = 100 η + 1 0 0 i(tT(x)

— K(n)'l(*T(n

* V ~ tv(n)>l

where tr(x) is the retention time of unknown species X, tT(n) is the reten tion time of the «-alkane eluting prior to X, tr(n + v is the retention time of the «-alkane eluting immedi ately after X, and η is the carbon number of the «-alkane with reten tion time tv(n). The qualitative accuracy of this procedure was confirmed with au thentic standards and by GC/MS

Table 1. Quality assurance protocols for exhaust emissions measurements Method

GC

LC

Analyte

Standards

Acceptance criteria

Total mass recovery with Retention index: 21 C,-C 1 2 a control limit of ±15% components (nominal 5 ppm or ±3.0 ppm compared C each; 2-4% traceability to with FID Ν 1ST) Quantitation: methane and propane primary standards (2% traceability to NIST) Quantitation: Three standards Analysis of each standard Methanol at 1.0, 5.0, and 10.0 ppm in quadruplicate with a and ethanol in water control limit of ±8% compared with leastsquares fit Quantitation: Three 12Control limits of ±10% Aldehydes at concentrations of >1.0 component mixtures in and ketones ng/mL, ±25% at 0.06-1.0 three concentration ranges μ9/ηιΙ-, and ±50% at -xylene and o-xylene. Although the concentration of each gas reference species was known within 2 - 4 % (95% confidence limits), this mixture was not used as a quantitative reference material. Instead, methane and propane (2% accuracy) were used as quantitative standards. The response factor for all hydrocarbons, except methane, was assumed to be directly proportional to the number of carbons, as verified in previous studies (7). Peak areas were used for quantitation of the hydrocarbons, and the FID response was nearly linear for the C j C, 2 hydrocarbons within the concentration range expected for this study. Recovery studies. One of the best tests for assessing the validity of an analytical technique is to "spike" a sample with the analytes of interest, carry out the analytical procedure, and determine the recovery of the "spiked" analytes. Various standards

Instrument computers

Site host computers (Ford, GM)

Instrument computers

Data collation (EDS)

Development of working data set (SAI)

Data distribution and data analysis

Figure 3. Computer protocols for the transmission, collection, and processing of emissions data.

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1154 A • ANALYTICAL CHEMISTRY, VOL. 63, NO. 23, DECEMBER 1, 1991

were injected into the exhaust or testing enclosure facility to determine the recovery of the sampling and analysis procedures. The recovery of methanol and hydrocarbons (propane) averaged from 93% to 98% for a series of experiments undertaken over several months. It was much more difficult to establish the recovery of formaldehyde because it is very polar and polymerizes easily. Injection of formaldehyde using a permeation tube or aerosolization of formaldehyde in solution gave recoveries averaging - 80%. Development of a new formaldehyde vapor injection system (18) resulted in recoveries that were consistently > 90%. Interlaboratory studies. Several interlaboratory round-robin and correlation studies were undertaken to help validate the analytical techniques. These studies were designed to distinguish differences among analytical techniques and variability among test facilities. A sample was prepared by the EPA Research Laboratory in Research Triangle Park, NC, for a hydrocarbon speciation interlaboratory roundrobin study. A small quantity of gasoline was injected into a gas cylinder filled with nitrogen and a low conc e n t r a t i o n of l i g h t h y d r o c a r b o n gases, and the tank was transferred among the Ford, GM, and EPA laboratories for analysis. The average hydrocarbon concentration as determined using a conventional total hydrocarbon FID analyzer was found to be 72.9 ppm C. The GC analyses showed that there were 95 components present at concentrations > 0.1 ppm C and that the average hydrocarbon mass accounted for was 71.2 ± 1.9 ppm C (98% recovery). The variation in quantitative results among laboratories was dependent on the concentration of the species a n d ranged from 4.7% RSD for concentrations > 3.0 ppm C to 23.1% RSD for concentrations < 0.5 ppm C. Another round-robin study was undertaken for the speciation of aldehydes and ketones. Known concentrations of these species were prepared in methanol and analyzed by Ford, GM, and EPA. The agreement between laboratories was excellent; RSDs ranged from 0.17% to 3.69%. D a t a b a s e m a n a g e m e n t . The testing program carried out during 1990 produced a very large data set that required development of a computer data strategy to facilitate data analysis. Figure 3 summarizes the computer protocols developed for

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handling these emission databases. Each analytical instrument has its own data system for control and data acquisition. The data from these systems were fed to site host computers, t h e n to Electronic D a t a Systems (EDS, a subsidiary of GM), where all the data were compiled into a common format. The d a t a were t h e n transmitted to Systems Applications Incorporated (SAI), where the working data set was converted to common units and put into a format that could be widely distributed and used. SAI also provided the three-dimensional atmospheric model calculations for determining ozone formation. All data files have been made available to the member companies, EPA, CARB, and other interested parties. Analytical results

Statistical analysis and atmospheric modeling studies have been under way since the Phase I testing prog r a m was completed in F e b r u a r y 1991. Overall, the analytical techniques have met or exceeded the program's requirements. The speciation procedures produced results with a high degree of reliability. The qualitative identification of chemical species was better t h a n 98% accurate above the 0.05 ppm (1.0 mg/mi) exhaust emission level. Although the analytical techn i q u e s could s p e c i a t e u p to 151 chemical components, only about half that number of species was quantified in any one test. Figure 4 shows the distribution of species as a function of carbon number for the paraffins, olefins, aromatics, and oxygenates for 20 1989 vehicles using one of the test fuels. Forty-four paraffins, 20 aromatics, 18 olefins, and 9 oxygenates were quantified in this set of tests. During the one-year period of the Phase I study, a Ford Aerostar and a Chrysler Dynasty were used in correlation studies to determine if there were any differences in analytical results between the GM and Ford testing facilities. These vehicles were transferred between the laboratories on a regular basis during the entire Phase I studies. For several selected hydrocarbons determined by GC, the agreement between the two laboratories was excellent, even down to the 0.1-ppm emission level. Seasonal variability was also studied by determining formaldehyde emission during winter (2/904/90), summer (6/90-8/90), and fall (9/90-11/90) periods at the Michigan

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emission of this compound during different times of the year. The correlation between the GM and the Ford labs for the Dynasty was within the reproducibility of the technique in each laboratory (±14%) at the 2.5 mg/mi emission level. As expected, the agreement between the two labs was not as good when the emissions levels approached the detection limit (~ 0.5 mg/mi). The instrumental precision of the GC analysis was also compared with the total test system precision for the measurement of individual species. GC instrument precision was determined by repeated injections of reference compounds at concentrations equivalent to the designated emission levels. Total test precision was determined from the speciation of emissions from repetitive vehicle tests using different facilities, vehicles, and instruments. Total test system precision averaged - 24%, 22%, 15%, and 14% at the 0.5-1.0, 1-2, 2 - 1 0 , and 1 0 - 4 0 mg/mi emission levels, respectively, for all vehicles (Figure 5). The GC instrumentation contributed < 25% to the total system variability above the 2 mg/mi level, and ~ 55% to the variability at the 0.5-1.0 mg/mi level. One method used to assess the quantitative recovery of hydrocarbons was a comparison of the total hydrocarbon emissions as d e t e r mined by the GC speciation and total FID hydrocarbon analyzer procedures. Recoveries below 100% would indicate hydrocarbon losses during sampling, the absence of significant

chemical species in the speciation procedures, or inaccuracies in either the FID or the GC procedures. The recoveries were calculated by summing the concentrations of all hydrocarbon and oxygenated species as det e r m i n e d by GC and HPLC and comparing these results with the total hydrocarbon values as determined by the total hydrocarbon analyzer procedure. For this analysis, the FID values were corrected for u n i t r e s p o n s e s to f o r m a l d e h y d e , methanol, methane, and MTBE. The agreement between these two methods was excellent; recoveries averaged 88.8% for the 1989 vehicles and 98.6% for the 1983-85 vehicles. T h e 151 s p e c i e s t y p i c a l l y a c counted for > 95% of the total mass of emissions. For both the current and the older fleets, the amount of unidentified material was significantly correlated with the T90 volatility level of the test fuel. For the current fleet, regression analysis showed that for fuels with high Γ 90 , the ana lytical technique identified an aver age of 4.3% less material than for fu els with low Tg0. For the older fleet, the analytical technique identified 2.3% less material for the high T90 fuels than for the low Ta0 fuels. This suggests that future improvements of the technique should include the ad dition of unidentified species to the GC library in the C10—C12 range. Future studies

Phase II studies will be continued over the next two years. Such studies will be undertaken to determine the

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Tailpipe emission level (mg/mi) GC instrument

Total test system 1989 vehicles Total test system 1983-85 vehicles

Figure 5. Comparison of gas chromatograph instrument precision with total test system precision.

1158 A • ANALYTICAL CHEMISTRY, VOL. 63, NO. 23, DECEMBER 1, 1991

durability of emission control sys tems using reformulated gasolines. Other alternative fuels (e.g., com pressed n a t u r a l gas) will also be tested. Testing of emissions from ad vanced systems is scheduled to in clude low-emission vehicles and im proved FFVs. Other efforts will be undertaken to determine the effect of catalysts on the reduction of individ ual hydrocarbons as well as the effect of reformulated fuels on specific ve hicle components (e.g., oxygen sen sors). New and improved analytical tech niques will be needed to support the Phase II programs. The Phase I GC method is being modified to improve detection limits by a factor of 10. This increased sensitivity is needed to measure the lower levels of emis sions produced by advanced technol ogy vehicles. A procedure is being developed for the simultaneous preand postcatalyst sampling of emis sions while a vehicle is operating under cyclic conditions. A method is also being developed for the collec tion and analysis of particle emis sions from reformulated and alter nate-fueled vehicles.

Program, approved by the California Air Resources Board, September 1990. (5) Burns, V. R.; Benson, J. D.; Hoch hauser, A. M.; Koehl, W. J.; Kreucher, W. M.; Reuter, R. M. Presented at the Fuels and Lubricants Meeting of the So ciety of Automotive Engineers, Toronto, Ontario, Oct. 1991; paper 912320. (6) Schuetzle, D. Health Perspectives J. 1983, 47, 65-80. (7) Lipari, F. /. Chromatogr. 1990,503, 51. (8) Sigsby, J. E.; Tejada, S. B.; Ray, W.; Lang, J. M.; Duncan, J. W. Environ. Sci. Technol. 1987, 21, 466-75. (9) Pelz, N.; Dempster, Ν. Μ.; Shore, P. R. /. Chromatogr. Sci. 1990, 28, 23035. (10) Rieger, P.; McMahone, W. Proceed ings of the 84th Annual Meeting of the Air and Waste Management Associa tion, Vancouver, British Columbia, June 1991; paper 91-107.3. (11) Warner-Selph, M. A. "Assessment of Unregulated Emissions from Gasoline Oxygenated Blends"; Southwest Re search Institute Technical Report, July 1990. (12) Horn, J. C; Hoekman, S. Κ Proceed ings of the Air and Waste Management Association Meeting, Anaheim, CA, June 1989; paper 89-9.3. (13) Code of Federal Regulations, No. 40, "Protection of Environment," Parts 86-99 (July 1, 1989). (14) Andino, J. M.; Butler, J. Environ. Sci. Technol. 1991, 25, 1644. (15) Kaiser, E. W.; Siegl, W. O.; Henig, Y. I.; Anderson, R. W.; Trinker, F. H. Environ. Sci. Technol., in press. (16) Rasmussen, R. Α.; Schuetzle, D.; Siegl, W. O., unpublished work. (17) Pahl, R. H.; McNally, M.J. Pre sented at the Fuels and Lubricants Meeting of the Society of Automotive Engineers, Tulsa, OK, Oct. 1990; paper 902098. (18) Schlenker, A. Chrysler Proving Ground, unpublished work.

The success of this collaborative effort was the result of valuable input from many scientists and engineers from supporting organizations, regulatory agencies, and other firms. Special thanks are given to R. Bisaro, R. Brown, S. Cadle, E. Chladek, D. Chock, R. Gorse, C. Kizlauskas, W. Kreucher, F. Lipari, J. Loo, J. McLeod, R. Muntz, M. Salata, J. Richert, A. Schlenker, W. Siegl, and S. Swarin from the auto industry; C. Burton, W. Clark, F. DiSanzo, H. Doherty, M. Levon, K. Hoekman, G. Musser, R. Pauls, L. Rapp, R. Reuter, and A. Schubert from the oil industry; P. Rieger and J. Shikiya from CARB; K. Knapp, J. Sigsby, S. Tejada, and F. Black from EPA, Research Triangle Park; A. Lloyd from the South Coast Air Quality Management District; W. Crowley, R. Denyszyn, and S. Miller of Scott Specialty Gases; P. Shore of Ricardo Consulting Engineers; L. Smith and M. Warner-Selph of Southwest Research Institute; and J. Pitts of Air Pollution Associates. In,addi tion, the authors appreciate the valuable com ments on this manuscript from J. Benson, D. Brooks, V. Burns, W. Koehl, D. Lawrence, D. Dennis Schuetzle (left), manager of the Meyer, and R. Pahl. Analytical Sciences Laboratory at Ford Motor Company, received his B.S. degree from California State University (San References Jose) in 1965. He received a Master's de gree from Stanford and the University of (1) Finlayson-Pitts, B. J.; Pitts, J. N., Jr. Atmospheric Chemistry: Fundamentals and California-Berkeley while working at the Experimental Techniques; John Wiley and Stanford Research Institute in 1968 and Sons: New York, 1986. (2) Seinfeld, J. H. Atmospheric Chemistry an interdisciplinary Ph.D. in analytical and Physics of Air Pollution; John Wiley chemistry and environmental engineering and Sons: New York, 1986. from the University of Washington in (3) Schuetzle, D.; Daisey, J. M. "Identifi 1972. He has edited three books, published cation of Genotoxic Agents in Complex more than 80 papers, and given more Mixtures of Air Pollutants" in Genetic Toxicology of Complex Mixtures; Waters, than 150 presentations on analytical and M. D. et al., Eds.; Plenum Press: New environmental chemistry. York, 1990. (4) "Federal Clean Air Act," Title II, Pub Trescott E. Jensen (right), principal re lic Law 101-549, amended 1990 and The Low Emissions Vehicle/Clean Fuels search scientist in the Analytical Sciences

Laboratory at Ford, received a Ph.D. in physical analytical chemistry from Brigham Young University in 1977 and worked as a postdoctoral research fellow associate at Indiana University before joining Ford. His research interests in clude development of analytical methods for complex environmental mixtures and vehicle emissions.

Donald Nagy (left), manager of the test technology group at the General Motors Ve hicle Emission Laboratory, received a B.S.E. degree in electrical engineering in 1973 and an M.S.E. degreein electrical en gineering in 1975 from the University of Michigan. He spent eight years as a project engineer designing large-scale automated vehicle emission test instrumentation. Prior to joining GM in 1976, he designed and de veloped space shuttle computer and elec tronics systems for the aerospace industry. Arnold Prostak (right), project engineer at the General Motors Vehicle Emission Laboratory, received a B.S. degree from the College of William and Mary in 1950; an M.A. degree from the Johns Hopkins University in 1955; and an M.S. degree in physics in 1960 and a Ph.D. in analytical chemistry in 1969 from the University of Michigan. He is primarily involved in de veloping instrumentation for measuring automotive emissions.

Albert Hochhauser, a regulatory and envi ronmental affairs adviser in the Products Research Division of Exxon Research and Engineering Company, received a B.E. de gree from Cooper Union in 1969, an M.E. degree from New York University in 1971, and a Ph.D. in chemical engineering from Carnegie-Mellon University in 1974. He is chairman of the Data Analysis and Report Writing Subcommittee of the Auto/Oil Air Quality Improvement Research Program. His current research focuses on gasoline properties and automotive emissions.


Analytical Chemistry and Auto Emissions - American Chemical Society

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