Particulate extract

Multidimensional chromatography has also been applied for the analysis of industrial chemicals and related samples. Industrial samples which have been analyzed by multidimensional chromatography include coal tar, antiknock additives in gasoline (3), light hydrocarbons (4, 5), trihaloalkanes and trihaloalkenes in industrial solvents (6-8), soot and particulate extracts, and various industrial chemicals that might be present in gasoline and oil samples. 

One example of normal-phase liquid chromatography coupled to gas chromatography is the determination of alkylated, oxygenated and nitrated polycyclic aromatic compounds (PACs) in urban air particulate extracts (97). Since such extracts are very complex, LC-GC is the best possible separation technique. A quartz microfibre filter retains the particulate material and supercritical fluid extraction (SPE) with CO2 and a toluene modifier extracts the organic components from the dust particles. The final extract is then dissolved in -hexane and analysed by NPLC. The transfer at 100 p.1 min of different fractions to the GC system by an on-column interface enabled many PACs to be detected by an ion-trap detector. A flame ionization detector (PID) and a 350 p.1 loop interface was used to quantify the identified compounds. The experimental conditions employed are shown in Table 13.2. 

Direct Reverted-Phase LC Analysis of Air Particulate Extract... 

Nishioka MG, CC Howard, DA Conros, LM Ball (1988) Detection of hydroxylated nitro aromatic and hydroxy-lated nitro polycyclic aromatic compounds in ambient air particulate extract using bioassay-directed fractionation. Environ Sci Technol 22 908-915. 

Diesel Particulate Extract PAHs (8) PAH (23) Nitro-PAHs (18)... 

May WE, and Wise SA (1984) Liquid chromatographic determination of polycyclic aromatic hydrocarbons in air particulate extracts. Anal Ghem 56 225-232. 

Beef muscle Homogenize, dilute with distilled water, centrifuge and filter to remove water-insoluble particulates extract onto solid-phase sorbents ITMS 50-100 ppb 20-50% Buchanan et al. 1995... 

Arey, J., W. P. Harger, D. Helmig, and R. Atkinson, Bioassay-Directed Fractionation of Mutagenic PAH Atmospheric Photooxidation Products and Ambient Particulate Extracts, Mutat. Res., 281, 67-76 (1992). 

Crebelli, R., S. Fuselli, G. Conti, L. Conti, and A. Carere, Mutagenicity Spectra in Bacterial Strains of Airborne and Engine Exhaust Particulate Extracts, Mutat. Res., 261, 237-248 (1991). 

Nishioka, M. G., C. C. Howard, D. A. Contos, L. M. Ball, and J. Lewtas, Detection of Hydroxylated Nitro Aromatic and Hy-droxylated Nitro Polycyclic Aromatic Compounds in an Ambient Air Particulate Extract Using Bioassay-Directed Fractionation, Environ. Sci. Technol., 22, 908-915 (1988). 

Paputa-Peck, M. C., R. S. Marano, D. Schuetzle, T. L. Riley, C. V. Hampton, T. J. Prater, L. M. Skewes, T. E. Jensen, P. H. Ruehle, L. C. Bosch, and W. P. Duncan, Determination of Nitrated Polynuclear Aromatic Hydrocarbons in Particulate Extracts by Capillary Column Gas Chromatography with Nitrogen Selective Detection, Anal. Chem., 55, 1946-1954(1983). 

Robbat, A., Jr., N. P. Corso, P. J. Doherty, and M. H. Wolf, Gas Chromatographic Chemiluminescent Detection and Evaluation of Predictive Models for Identifying Nitrated Polycyclic Aromatic Hydrocarbons in a Diesel Fuel Particulate Extract, Anal. Chem., 58, 2078-2084 (1986). 

Zinbo, M., D. Schuetzle, D. P. H. Hsieh, N. Y. Kado, J. M. Dasiey, and L. A. Gundel, An Improved Fractionation Procedure for the Bioassay-Directed Chemical Analysis of Ambient Air Particulate Extracts, Anal. Sci., 8, 461-468 (1992). 

Clark, C.R. and Vigil, C.L. (1980). Influence of rat lung and liver homogenates on the mutagenicity of diesel exhaust particulate extracts, Ihxicol. AppL Pharmacol. 56,110. 

Figure 2. Gas chromatogram of A, PAH fraction of diesel particulate extract (Sl-C2) and By its HPLC subfraction C (S1-C2). GC conditions 45- X 0.35-mm id SE54 glass capillary column flame ionization detector temperature, 110°C for 2 min, programmed to 170°C at 10°/min, to 212°C at 3°/min, to 278°C at 8°/min. Peak identities 1, phenanthrene 2, anthracene 3-6, methylanthracene/-phenan-threne 7, 2-phenylnaphthalene 8-10, dimethylanthracene/-phenanthrene 11, fluoranthene 12, aceanthrylene/acephenanthrylene 13, pyrene 14-15, trimethylan-thracene/-phenanthrene 16, benzo [ghi]fluoranthene 17, benzo[a/anthracene 18, triphenylene 19, chrysene 20, benzo[b]fluoranthene 21, benzo[]]fluoranthene ...

Figure 13.16 LC separation of urban air particulate extract (a), along with the GC/FID chromatogram (b) of an oxy-PAC fraction (transferred via a loop-type interface). Reprinted from Environmental Science and Technology, 29, A. C. Lewis et al., On-line coupled LC-GC-ITD/MS for the identification of alkylated, oxygenated and nitrated polycychc aromatic compounds in urban air particulate extracts , pp. 1977-1981, copyright 1995, with permission from the American Chemical Society.

Ion chromatography has also been used in air pollution studies to measure anions and cations in an air impinger solution and air particulate extracts. 

A final example of totally automated HPLC (although it isn t for pesticides) will demonstrate how many different unit operations can be done in a single system to take the tedium out of repetitive analyses. The drug analyzer depicted in Figure 14 was designed to determine therapeutic levels of theophylline in human serum (8). The sampler (in the center) aspirates 50 uL of serum into the analytical cartridge, then to the EDM, and finally to the LC module. The following series of operations takes place at the rate of 20 samples per hour without operator intervention unmeasured, untreated sample is aspirated, diluted with buffer, and mixed with an internal standard the system then precipitates the protein, removes the particulates, extracts the analyte (and internal standard) into... 

Assemble a glass funnel filled approximately onehalf full with sodium sulfate such that the funnel will drain into the K-D concentrator or round bottom flask from Paragraph 9.6.4.1 containing the concentrated methylene chloride extract of the filtrate (You may use the same funnel from Paragraph 9.5.2 or 9.5.3). Pour the concentrated toluene extract of the particulates through the sodium sulfate into the K-D concentrator or round bottom flask. Rinse the flask from the particulate extract with three 15-20 mL volumes of hexane and pour each rinse through the sodium sulfate into the K-D concentrator or round bottom flask. 

Kelly GW, Bartle KD, Clifford AA, et al. 1993. Identification and quantitation of polycyclic aromatic compounds in air particulate and diesel exhaust particulate extracts by LC-GC. J Chromatogr Sci 31(3) 73-76. 

Naikwadi KP, Charbonneau GM, Karasek FW, et al. 1987. Separation and identification of organic compounds in air particulate extracts by high-performance liquid chromatography and gas chromatography-mass spectrometry. J Chromatogr 398 227-238. 

Figure 1. Chromatograms of airborne particulate extracts (A) and NPAHs standard (B)...

Figure 7.14. HPLC analysis of polynuclear aromatic hydrocarbons (PAHs) in an air particulate extract sample collected from the Long Island Expressway, New York, using programmed fluorescence detection. Reprinted with permission from reference 26.

Schuetzle D, Lee FSC, Prater TJ (1981) The identification of polynuclear aromatic hydrocarbon (PAH) derivatives in mutagenic fractions of diesel particulate extracts. Intern JEnviron Anal Chem 9, 93-144. 

From these data it appears that through the action of specific inositol phosphatases both IP3 and IP4 are sequentially dephosphorylated to free inositol (cf. Fig. 2). The dephosphorylation of IP3 requires Mg2+ and physiological concentrations of Ca +. The inositol phosphate phosphomonoesterase is inhibited by Li+, but the IP3 5 -phosphomonoesterase is not inhibited (Carsten and Miller, 1990). Interestingly, soluble and particulate extracts from porcine skeletal muscle also metabolize IP3 and IP4 to inositol in a stepwise fashion (Foster et al., 1994). Apparently, smooth and skeletal muscles have the same set of inositol polyphosphate phosphatases, although their functional role in skeletal muscle is not known. 

One of the earliest works using HPLC-DAD for the identification of the large PAHs involved the analysis of a diesel particulate extract [16-18]. About a dozen LPAHs were found. The identifications made were later correlated to the observed mutagenicity of this diesel particulate. A carbon-black extract, obtained from the same carbon black was examined by HPLC-DAD. The DAD, as well as a much larger collection of standard compounds, allowed the identification of around 20 more LPAHs than in earlier studies of this same material. 

Each particulate extract was separated into four chemical compound classes using open-bed silica gel column chromatography (1) aliphatic hydrocarbons—hexane elution, (2) polycyclic aromatic hydrocarbons—hexane benzene (1 1 v/v) elution,... 

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