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Using thermal electrons and positive reactant ions from nitrogen gas, both positive and negative plasmagram patterns have been obtained for fluorobenzene, chlorobenzene, bromobenzene, and iodobenzene. The plasmagrams give characteristic qualitative data. Positive plasmagrams show protonated molecular ions containing one and two molecules; the negative plasmagrams, except for the fluorobenzene, show only a strong halogen ion peak, which provides experimental evidence for dissociative electron capture by thermal electrons. (Author)

The formation of polychlorinated dibenzofurans (PCDFs) and polychlorinated dibenzo-p-dioxins (PCDDs) in catalytic reforming, a petroleum refining process, was studied using a laboratory apparatus. Conditions in the catalyst regeneration step in catalytic reforming were simulated, and the reactions of precursor compounds for the formation of PCDFs and PCDDs were studied. No PCDFs/PCDDs were produced by the reforming catalyst and potential precursors under any conditions studied. During treatment of the coked catalyst, dibenzofuran (DBF) was found in the flue gases. Chlorination experiments with flue gas concentrates and standard solutions in the presence of FeCl[sub 3] and HCl or Cl[sub 2] in the temperature range of 220-540 [degrees]C indicated that DBF can be chlorinated to PCDFs. A precursor mixture of 1,1,1-trichloroethane (TCE) and CCl[sub 4] in hexane also produced PCDFs by de novo formation. 10 refs., 5 figs., 2 tabs.

Carcinogenic and genotoxic polycyclic aromatic hydrocarbons (PAHs) were detected in coal fly ash samples. Further analysis of these samples also revealed the presence of highly toxic polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). The amount of PCDD/PCDF detected were in the parts per trillion (ppt) levels. Although coal fly ash contains a large number of organic compounds, the levels of PCDD/PCDF detected were two to three orders of magnitudes less than what has been observed in municipal solid waste incinerator (MSWI) fly ash samples. To investigate the probable reason for low levels of PCDD/PCDF in coal fly ash samples, catalytic activity tests were conducted using C-13 pentachlorophenol as the precursor. Results indicate that the formation mechanism of PCDD on coal fly ash is analogous to that on MSWI fly ash.

There are very few studies on the mechanism of formation of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and related compounds in industrial waste incinerators (IWIs) and possible techniques to prevent their formation. It has been shown in our laboratories that fly ash from municipal solid waste incinerators (MSWIs) catalyzes the reactions leading to the formation of PCDD/PCDF at about 300 to 400°C. In the current investigation laboratory experiments were conducted to study the catalytic activity of the samples from an IWI towards the formation of PCDDs and PCDFs from precursors. Results show that IWI samples are catalytically active towards the formation of PCDDs. Several inhibitors and their mixtures such as inorganic and organic bases were tested to study their effect on the catalytic activity of the IWI samples and MSWI fly ash samples towards the prevention of formation of PCDD/PCDF from precursors.

Four different side chain liquid crystal polysiloxanes were synthesized and evaluated as stationary phases for dioxin and furan analysis, focusing on isomer specific separations and analysis of those containing substitution at positions 2,3,7 and 8. The selectivities of the stationary phases were found to vary according to their mesophase range and degree of order of the liquid crystalline lattice. Reproducibility was investigated by testing three separate batches of one of the products.

Four method for the extraction of polychlorinated dibenzo- p -dioxins and dibenzofurans in municipal solid waste (MSW) incinerator fly ash samples were examined. A Soxhlet method was found to be the most efficient. However, the time required for extraction was more than 24 h. Ultrasonic extraction (UE) proved to be an inexpensive, efficient, reliable and rapid method. Studies of the effect of extraction time and temperature in UE showed that higher temperatures, longer times of extraction and increased number of repeated extractions with fresh solvent resulted in higher extraction efficiency.

A newly developed side chain liquid crystal polysiloxane has been investigated as a stationary phase for the isomer-specific analysis of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans substituted at positions 2, 3, 7, and 8. The retention times from the chromatograms of a standard solution containing all PCDD and PCDF isomers were compared with those from solutions containing only those tetra- to octa-chlorinated compounds substituted at positions 2, 3, 7, and 8. In general, PCDDs substituted at positions 2, 3, 7, and 8 eluted later than most other isomers of the same congener group. The separations obtained on this stationary phase were compared with those obtained elsewhere using a commercially available product.

A database with the ion masses, isotopic abundances, and number of isomers of polyhalogenated (chlorinated and/or brominated) dibenzo-p-dioxins (PXDD), -furans (PXDF) and related compounds has been created with a Pascal program. This database allows the selection of ion masses for selected ion monitoring, checking for interfering ions, postulating electron impact (EI) spectra for not readily available compounds, finding the number of possible isomers or the listing of isomers with specific topological properties.

Analysis of polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF) has been performed using gas chromatography mass spectrometry (GC-MS). Analysis of the most toxic isomers, in particular, 2,3,7,8-substituted PCDD/PCDF in the presence of other isomers requires a special isomer specific capillary column or high performance liquid chromatography (HPLC) fractionation prior to GC-MS analysis. Commercially available long (>50 m) polar columns can separate 2,3,7,8-TCDD from other tetra isomers. However, those columns are not satisfactory for the analyses of total PCDD/PCDF in the environmental samples. Gas chromatography -high resolution mass spectrometry (GC-HRMS) and GC-MS/MS techniques are not helpful in the analysis of 2,3,7,8-TCDD unless it is separated from the other tetra isomers. The analysis of 2,3,7,8-TCDD and total PCDD and PCDF in a single GC-MS run can ease the laborious techniques presently used. In this study we have developed a new stationary phase for the GC capillary column. The capillary column developed using this new stationary phase showed unsurpassed selectivity for the separation of 2,3,7,8-TCDD from other tetra isomers. There are several advantages of the newly developed GC capillary column.

Several samples collected at the post-combustion zone of the Machida incinerator in Japan were analyzed for polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), polychlorinated phenols (PCPs) and polychlorinated benzenes (PCBEs). All samples show lower levels of PCDDs and PCDFs in comparison to the levels of observed in other samples from various incinerators around the world. The Machida incinerator in Japan shows ten times lower levels of PCDDs/PCDFs than the Ontario incinerator in Canada. Analyses of fly ash samples collected at different points in the post-combustion zone shows higher levels of PCDDs/ PCDFs at points near the stack, and decreasing towards the combustion zone. That trend indicates the formation of PCDs/PCDFs in the electrostatic precipitator by catalytic activity of fly ash in addition to their probable formation in the incinerator furnace. Variations in normal operating conditions have no or very little effect on the amount of PCDDs/PCDFs formed. Municipal solid waste in Japan has been separated into combustible and non-combustible materials. Only the combustible materials were incinerated in the Machida incinerator, which is fluidized bed design with CaO inject into the bed.

The use of a plasma chromatograph as a gas chromatographic (GC) detector is described. It not only duplicates the capabilities of many known detectors, but also gives low-resolution qualitative detection of chosen compounds. Detection of GC effluents comparable to the flame ionisation and electron capture detectors is demonstrated using positive and negative modes of operation of a research-oriented instrument. A tunable mobility detection of both positive and negative ions selected in the mobility spectra of given compounds provides highly sensitive, and low-resolution qualitative detection of GC effluents. The use of this technique is facilitated by the availability of a number of reference spectra of different classes of compounds previously reported. Further development of the plasma chromatographic instrumentation for multi-mode detection of GC effluents is suggested.

Airborne particulate matter was collected on high-volume glass fiber filters for analysis of the organic fraction by gas chromatography-flame ionisation detection and gas chromatography-mass spectrometry techniques. Exhaustive solvent extraction followed by concentration through condensation results in a sample suitable for gas chromatographic analysis. Although cyclohexane is the solvent most commonly used for extracting organic compounds from atmospheric particulate matter, methanol was found to be more effective for this extraction. It extracted more components in larger quantities and in less time than did cyclohexane. The methanol extraction from particulates collected on glass fiber filters appears to be effective for collections of both aliphatic and polycyclic aromatic compounds and organic acids. An inorganic precipitate which forms during the condensation of the methanol extract from 200 ml to 1 ml is removed by centrifugation.

The use of dimethyl sulphoxide (DMSO) as a solvent causes difficulties in the analysis of trace organics in complex mixtures bay gas chromatography (GC) and gas chromatography—mass spectrometry (GC—MS). The high boiling point of DMSO causes problems in the concentration of trace organics. A semi-preparative high-performance liquid chromatographic (HPLC) separation procedure with gradient elution was employed to provide a means of solvent exchange for the analysis of organic mixtures in DMSO. This method was demonstrated using a DMSO solution of an extract of airborne particulate matter. After HPLC separation, a number of polynuclear aromatic hydrocarbons and their derivatives were identified by GC—MS and GC analysis.

A short-term test for human cellular response to toxic environmental chemicals using peripheral blood leukocytes and high-resolution two-dimensional electrophoresis is demonstrated to be feasible by using extracts of organic compounds from municipal incinerator fly ash and from particulates of diesel exhaust and air-borne particulates. The effect of the chemicals on the normal synthesis of about 2000 proteins by the leukocytes is observed. Three types of effects by adding increasing amounts of chemicals are found: proteins whose synthesis is blocked easily; those that are quite resistant; and the appearance of new proteins. The type of effect which predominates appears to be related to composition of the organic extract. It is anticipated that this test can directly measure the toxic, genotoxic, and mutagenic behavior of individual chemicals or mixtures on human cells. 8 figures, 1 table.

Large and variable background currents are observed in the normal operation of a five-stage radio frequency mass spectrometer. A hypothesis of resonance charge transfer collisions occurring in the mass analyzer can explain the cause of these currents. Positive ions of excess energy, generated by the partial neutralization of doubly charged ions, give rise to a positive background. Also produced in the charge transfer collisions are high energy neutral particles. Bombardment of the final grid of the mass analyzer by these neutral particles causes secondary electron emission. Detection of the secondary electrons results in a negative component of the background. By operating the instrument with an ion deflector and an offset detector, the background ions from the mass analyzer, as well as the secondary electron currents, were eliminated. However, the background problem was not entirely solved due to low energy background ions which were generated at the ion deflector. Alternative solutions to the background problem are suggested.

A Teflon block extraction apparatus for the determination of trace organic material from airborne particulate matter collected on Teflon dichotomous filters has been constructed and evaluated. The total solvent volume of 5–6 ml minimizes artifact introduction from solvents and component loss during condensation. Viton O-rings were found to be a source of artifacts and the total artifact level is reduced significantly upon replacement of the Viton O-ring with Teflon. With the use of the all-Teflon apparatus the expected minimum detectable amount is 10 pg/m 3 of air sampled.

A gradient, normal-phase high-performance liquid chromatographic (HPLC) separation procedure that effectively provides a compound class separation was applied to the analysis of extracts of flyash from municipal incinerators in Ontario, Canada and Oslo, Norway. Each fraction collected from the HPLC procedure was analysed by capillary gas chromatography and capillary gas chromatography-mass spectrometry. More than 200 organic components were identified in the canadian extract. The polychlorinated dibenzodioxins (PCDDs) were exclusively eluted in one fraction, which facilitated their quantitation. The retention indices of some environmentally important polychlorinated organic compounds were determined with an average standard deviation of 0.023. The average recovery of the PCDD compounds in the HPLC separation step was 105% with a relative standard deviation of 6.8%.

The performance of a five-stage Bennett-type mass spectrometer was investigated by computer simulation. By calculating the trajectories of ions through the mass analyzer, the behaviour of the instrument under a variety of operating conditions was studied. The resolving power of the instrument is improved when the waveform of the radio frequency (rf) potential is changed from a sine wave to a square wave. Variations in the d.c. voltages applied to the mass analyzer were found to have a greater effect on resolution in the square wave mode of operation than in the sine wave operation of the device. It was also shown that the electrode potential distribution of the mass analyzer affects the sensitivity of the instrument. When separate d.c. potentials are applied to the grid electrodes to keep ions at constant velocity, the sensitivity is uniform over a wide mass range. When the rf grids are connected to a single d.c. potential, a discrimination against light ions was predicted. The transmission of harmonic ions through the mass spectrometer was also studied. The positions of harmonic peaks in a mass spectrum were computed accurately, but the energy gain calculated for those ions differed from experimental results. Differences between observed and predicted results were attributed to the non-ideal characteristics of the actual grid system. The computer models should prove to be a useful guide in the evaluation of new instrument configurations.

Four cis- and trans-dimethyl ester isomers resulting from the photolysis of o-isopropenylbenzophenone with dimethyl maleate or dimethyl fumarate were separated by gas chromatography (GC) with sufficient resolution for qualitative and quantitative analysis using a glass column packed with Aue packing. Both the GC-mass spectrometry (MS) analysis and Kovats' retention indices of these compounds were obtained. Only one of the four mass spectra exhibited significant differences from the others, primarily in the intensity of the molecular and base ions. Analytical methods are described for rapid analysis of mixtures of these compounds by either GC or GC-MS.

High resolution gas chromatography—flame ionization detection (GCFID) with on-column injection was used for quantitative analysis of oxy-polycyclic aromatic hydrocarbons (oxy-PAH), nitro-PAH, and phthalate esters in the extracts of three different diesel exhaust particulate samples. Various compounds in the extracts were sorted into different compound classes by high-performance liquid chromatography fractionation and then, components were tentatively identified by GC—mass spectrometry and retention indices. Combined with the quantitative results obtained in previous studies, the comparative quantitative bar diagrams with more than one hundred polycyclic aromatic compounds were constructed for these three diesel particulate extracts. Some results of the quantitative analysis can be related to response in a toxicity test of the original extracts.

A complete separation of PDDD and PCDF from a complex sample matrix by a two-step HPLC clean-up procedure shows the feasibility of analysis of PCDD and PCDF using less expensive instruments. This is demonstrated by a comparison of quantitative results of PCDD and PCDF in a complex flyash sample analyzed using GC/FID, GC/ECD, and GC/MSD.

Fly ash-catalysed surface reactions are probably the most important mechanism in the formation of chlorinated dibenzo-p-dioxins (PCDD) and related compounds in municipal incinerators. The introduction of a suitable catalyst inhibitor should decrease the yield and change the distribution of PCDD formed on the fly ash. The addition of catalyst inhibitors containing amino- and hydroxy-functional groups to the fly ash surface greatly inhibited the catalytic activity of the fly ash. 2-aminoethanol and triethanolamine were the most effective catalyst inhibitors. The significance of these results to controlling the emissions of PCDD from municipal refuse incinerators is discussed.

It has been observed that polychlorinated dibenzo-p-dioxins (PCDD) and dibenzofurans (PCDF) can form from various precursors by catalytic activity of municipal incinerator fly ash between 200 and 400 °C. Study of the effect of temperature on PCDD formation shows that tetra- to octachlorodibenzo-p-dioxins form in greater amounts at 300°C. The catalytic activity of fly ash for formation of PCDD appears to be associated with various metals present. The catalytic reactions of fly ash to form PCDD and PCDF from various precursors at different temperatures can be inhibited using certain chemical reagents. Organic and inorganic basic compounds were tested as inhibitors in the laboratory experiments. Separation, identification and quantitation of dioxins and other compounds formed from precursors and with inhibitors on fly ash were carried out using GC-FID, GC-ECD and GC-MS techniques. Advantages and disadvantages of various inhibitors will be discussed as a technology to prevent PCDD and PCDF formation in MSW incinerators.

Obtaining accurate quantitation of 1-nitropyrene in a complex mixture is difficult because of variable decomposition occuring in the analytical system at the low 10–100 ng quantities involved. The procedure described here involves pre-separation of the extract by high-performance liquid chromatography and analysis by both capillary gas chromatography and capillary gas chromatography—mass spectrometry. A modified cool on-column injection technique and bonded phase fused silica capillary columns were used to minimize the decomposition and improve the precision for the quantitative analysis. The method is demonstrated using four different diesel particulate extracts containing 1-nitropyrene in the 10–100 ng/μl range.

Plasma chromatography as a method for ultratrace qualitative and quantitative detection of organic compounds is especially well suited for detection of gas chromatographic effluents. The optimum range of sample quantity is 10-6 to 10-12 g for detection and identification of a compound by use of its characteristic positive and negative mobility spectra. The type of reference mobility spectra produced by alkanes, aromatics, esters, halogenated compounds, nitrogenated compounds and organic acids have been previously reported. This study presents the reference mobility spectra produced for lysergic acid diethylamide (LSD), delta-9-tetrahydrocannabinol (delta-9-THC), digitoxigenin and several biochemical compounds of research significance. LSD and delat-9-THC in a mixture can be detected and identified by plasma chromatography positive mobility spectra in quantities of 10-7 g or less. All the compounds investigated in this study display strong MH-+ ions along with other ions primarily of the type (M)NO-+, (M)2H-+. None of these compounds exhibits negative mobility spectra.

1-Nitropyrene was found to decompose during gas chromatographic-mass spectrometric (GC-MS) analysis. Decomposition was observed both on the column and after the column. The decomposition product was tentatively identified as aminopyrene. Extracts of an air particulate sample and an electrostatically precipitated flyash sample from a municipal incinerator were examined for the presence of 1-nitropyrene. The compound was identified in the air particulate extract at the low ppm level, but was not detected in the fly-ash sample. A stable isotope standard was employed to compensate for the lability of the 1-nitropyrene in the GC-MS system to assure positive identification and quantification of the low levels present in air particulates.

Polychlorinated dibenzo-p-dioxins (PCDDS) are a group of compounds consisting of 75 isomers which are difficult to quantitate because of the lack of sufficient reference standards. A method of quantitation is developed which uses relative response factors for each isomeric group. Variations in gas chromatographic—mass spectrometric parameters do not bias the quantitation method for PCDDS. Testing the method using an environmental sample gives consistent data that can be used to study PCDD content in a number of samples.

Concentrated methanol extracts of airborne particulate matter (APM) collected on glass fiber filters were examined by gas chromatography to document sample composition changes during storage. A major component of the chromatographic profile was observed to decrease in abundance with time while another compound was increasing. These compounds were identified by Gas Chromatography-Mass Spectrometry as myristic acid and methyl myristate, respectively. Although methanol is a common extracting solvent for these samples, this is the first study to document the in-situ esterification of acids from APM during storage of the methanol extracts.

Three Amberlite polymeric resins, XAD-2, XAD-4 and XAD-7, were evaluated for extraction efficiency from aqueous media of several organic compounds representing pesticides, polyaromatic hydrocarbons, phenols and phthalate esters. The three resins exhibited different extraction characteristics. The extraction efficiency of the resins was found to be dependent on pH conditions and, on the average, was best at pH7. At this pH the XAD-2 and XAD-4 resins yielded quantitative recoveries in the 90–100% range for most compounds at the 20–200ppb level. Recoveries by XAD-7 resins were lower for several compounds. The recovery of aldrin and o, p DDT under all conditions was relatively low (>68%) and showed a higher degree of variability than that obtained for the other compounds. Alkaline pH conditions were generally unfavourable for the extraction of phenolic compounds but acidification to pH2 was not found to be a necessary step for the quantitative extraction of the phenolic compounds. Acidification to pH...

A plasma chromatograph functions as a very sensitive qualitative detector for a gas chromatograph. Compounds in a gas chromatographic peak are detected in nanogram or less quantities and identified by their characteristic positive and negative mobility spectra. General relationships observed indicate that all compounds show simple positive mobility spectra similar to those obtained in chemical ionization mass spectrometry, giving prominent molecular-type ions, occasionally associated with fragment ions. The simple negative mobility spectra which consist of molecular and dissociative ions are produced only by those compounds that undergo electron attachment. Reference mobility spectra for the different compound classes of n -alkanes, alcohols, ketones, halogenated aromatics, substituted nitrobenzenes, polychlorinated biphenyls, alkyl halides and 1-nitropropane are given.

A plasma chromatograph can function as a very sensitive, qualitative detector for a gas chromatograph. Sample components in a gas chromatographic peak can be detected in quantities of 106 to 1012 g and be identified by their characteristic positive and negative mobility spectra. The types of reference mobility spectra produced by alkanes, aromatics, esters, halogenated and nitrated compounds have been previously reported. This study presents the reference mobility spectra produced for benzoic and isomeric phthalic acids and some of their esters. All these compounds display strong positive mobility spectr containing abundant ions of the MH . (M :H2O)H-(M)NO and (M R)H type. Benzoic acid, benzaldehyde and terephthalic acid give no negative mobility spectra, while the other compounds and esters show negative mobility spectra whose prominent ions are of the M or (M H2O) type.

Polychlorinated dibenzo-p-dioxins (PCDDs) and other organic compounds are solvent extracted from 10- to 20-g samples of fly ash from municipal incinerators with 200 mL of benzene using ultrasonic agitation for 1 h. A convenient filtering device is used to separate fly ash and solvent which is then concentrated to 100 ..mu..L using a rotary evaporator. Extracts are analyzed directly by gas chromatography/mass spectrometry, including selected ion monitoring for PCDDs. Results from five replicate analyses of a fly ash sample yielded averages and standard deviations (ng/g) for the tetra-to octachlorinated dibenzo-p-dioxins of 8.6 +- 2.2, 15.0 +- 4.0, 13.0 +- 3.4, 3.2 +- 1.0, and 0.4 +- 0.1, respectively. 2 tables, 3 figures.

A mixture containing polyethylene, polystyrene, and polyvinyl chloride was subjected to oxidative thermal degradation at temperatures of 800–950°C. Breakdown products were collected on glass wool or in cold traps for analysis by capillary gas chromatography and gas chromatography—mass spectrometry. Combustion products included alkyl benzenes, hydrocarbons, alkenes, biphenyls, and polycyclic aromatic hydrocarbons containing from two through six rings.

Two different samples of fly-ash have been separated into different size fractions by manual sieving using standard screens. Both samples showed the same trends of relative distribution of organic compounds on fractions. Average particle sizes for the various fractions were: 30 μm, 80 μm, 125 μm, 200 μm, 550 μm and particles > 850 μm. Each fraction was extracted with benzene by ultrasonic agitation, and the concentrated extracts analyzed by gas chromatography and gas chromatography—mass spectrometry for total organic compounds, n -alkanes, phthalates, selected polynuclear aromatic hydrocarbons and polychlorinated dibenzo- p -dioxins. The largest concentrations of tetra- and pentachlorodibenzo- p -dioxins occured on the larger (550 μm) particles while the 30-μm particles had greater relative concentrations of octachlorodibenzo- P -dioxin. The largest(> 850 μm) sized fraction consisted of two distinctly different types of particles. One of these types was lights, black-ash particles such as are obtained from the combustion of newsprint. These light ash particles had high concentrations of total organic compounds and tetrachlorinated dioxins, relative to the other size fractions. Printed words could still be discerned on some of these ash particles, indicating that these particles escaped complete combustion.

Four sorbent materials, Tenax-GC, Chromosorb 101, Florisil, and Carbopack C HT were characterized using elution analysis by gas chromatography for chlorinated benzenes, chlorianted phenols, Aldrin and Aroclor 1242. Plots of log Vn versus °K−1 were linear with correlation coefficients of 0.992–1.000. Chlorinated phenols, Aldrin and Aroclor 1242 were not eluted on a Florisil column at temperatures as high as 325–375°C. Specific retention volumes, which were calculated for 20°C using results from linear regression analysis, generally followed the order: Tenax-GC > Chromosorb 101 > Carbopack C HT. At 250°C, measured specific retention volumes generally followed the order: Chromosorb 101 > Carbopack C HT > Tenax-GC. These results show that analytical procedures based on thermal desorption techniques may be developed for the determination of these chlorinated organic compounds. Tenax-GC is the best sorbent material based on retention properties.

The preparation and use of large-bore open-tubular (LBOT) and porous-layer open-tubular (PLOT) columns are described. A simple yet versatile coiling apparatus has been devised that is useful for capillary as well as 1 8 -in. tubing of any length. Several types of frames for long LBOT columns can be employed. A rigorous cleaning method for stainless-steel tubing is also detailed, and an apparatus for reproducibly coating LBOT or PLOT columns is presented. These two types of columns yield comparable efficiencies, but the LBOT columns could be prepared more easily and reproducibly.

Methodology is developed for the isolation and identification of organic constituents present in inorganic water treatment chemicals. Solid and liquid samples are analyzed by gas chromatography—mass spectrometry using two complementary ionization techniques, electron impact and positive ion chemical ionization. Actual samles representative of the most commonly employed water treatment chemicals were obtained from a variety of sources. The majority of the organic contaminants found to be present in these samples contain only carbon, hydrogen, oxygen, and in some cases nitrogen. In the twenty-four samples analyzed only a total of three chlorinated species were identified. The total ortanic content of the various chemicals studied was found to range from 0.01 to 300 ppm, however, most samples contained less than 10 ppm.

Distilled-in-glass and pesticide grade solvents commonly used in analyses of environmental samples for organic compounds at trace concentration levels were condensed 2000 fold and analyzed by gas chromatography, gas chromatography- mass spectrometry and selected ion monitoring. Cyclohexane, methylene chloride and methanol solvents each contained an estimated total of 1–150 ng of organic impurities per ml of uncondensed solvent. Impurities identified by mass spectra included phthalate esters, n -hydrocarbons and chrlorinated ydrocarbons; however no solvent contained all of these impurities. Pesticide grade solvents contained up to 21 components with maximum concentrations per single component of 30–50 ng/ml in the uncondensed solvent. Distilled-in-glass grade solvents had fewer and lesser amounts of similar impurities, and were found to be the most suitable for trace organic analysis.

The quantitative response factors (RF) of fourteen long-chain normal alkanes were determined for gas chromatography—mass spectrometry with electron-impact (GC—EIMS) and chemical ionization (GC—CIMS). IN GC—EIMS analysis, the compounds tested gave very similar RF/unit weight (RF/W) to the total ion current (TIC) and to the mass chromatograms of some characteristics fragment ions. In the GC—CIMS analysis, the alkanes showed similar RF/mol (RF/M) to TIC. However, an average RF/M for the quantitation of a large number of compounds using GC—CIMS could not be developed because of the considerable variations involved.

A cleanup method employing two HPLC fractionations was devised for the determination of 2,3,7,8-TCDD in fish tissue. Initial fractionation on silica normal phase HPLC separates 2,3,7,8-TCDD from the bulk of the sample matrix. A second HPLC cleanup using an alumina column isolates the 2,3,7,8-TCDD from polychlorinated pollutants such as PCBs.

All incinerators burning municipal waste produce chlorinated dioxins. The mechanism by which these compounds are formed is unknown. Experiments were performed that show these compounds can be produced from known precursors by surface catalysed reactions on the flyash particulates present in the incineration process. A full range of the tetra- through octachlorinated dibenzo-p-dioxins were produced from 13C-labelled pentachlorophenol and two trichlorophenols on the surface of flyash from an Ontario municipal incinerator that had been previously freed from organic material. A simple flow-tube apparatus at 300 degrees C under a 10-ml/min nitrogen flow was used for the experiments. The use of 13C-labelled pentachlorophenol gave a direct measure of the extent of the catalytic reactivity of the flyash surface. Much lower amounts of chlorinated dioxins were produced in similar experiments with flyash from a modern Japanese incinerator whose effluents are normally extremely low in these compounds. Only small amounts of octachlorodioxin, the thermal condensation product expected, were formed using ground firebrick or an empty flow-tube for the reactive surface. These results indicate that the flyash surface has constituents and properties that promote the production of chlorinated dioxins from chlorinated phenols and support the catalyzed surface reaction mechanism previously proposed.

A high-performance liquid chromatography (HPLC) method has been developed for the separation of aromatic compounds from the saturated hydrocarbons in lubricating oil base stocks and the further separation of polycyclic aromatic hydrocarbons (PAHs) into fractions based on the number of fused rings. Aromatic compounds were separated from the saturated hydrocarbons by HPLC using a silica column. The aromatic compounds were then backflushed onto an amine derivatized silica column using a six-port two-position switching valve. The PAHs were separated according to the differing number of fused rings. Further analysis by high-resolution gas chromatography—low-resolution mass spectrometry with a fused-silica DB-5 capillary column showed the presence of various parent and alkylated PAHs in the lubricating oil base stocks and 10W30 oil at the part per billion (10°) level.

Automatic calculation and plots of Kovat' retention indices (RI) from gas chromatographic (GC) analysis of environment samples is provided by a calculator- controlled GC—mas spectrometric (MS) system. The retention indices framework of carbon numbers is set up using a standard sample containing all the desired n -hydrocarbons which are automatically identified in a GC—MS run by the presene of the m/e 85.1 C 6 H 13 + ion and the molecular ion. These standard retention data are used to automatically calculate RI values for samples extracted from airborne particulate matter run under identical GC conditions. n -Hydrocarbons present in a sample can be employed as internal standards but an editing subroutine may be necessary to remove ambiguities. Standard deviation of a test of the external standard method is 2.4 RI units, of the internal standard method 1.5 RI units.