L.L. Lamparski

Determination of trace phenols in water by gas chromatographic analysis of heptafluorobutyryl derivatives

Abstract An analytical procedure is described that permits the determination of phenol and substituted phenols, which do not possess inherent electron-capture sensitivity, at concentrations ⩾10 ng/ml in aqueous media by gas chromatographic analysis of the heptafluorobutyryl derivatives. Sample pre-concentration is not required, and a single benzene extraction removes phenolics from the water matrix prior to derivatization. The gas chromatographic analysis is performed on a column packing which exhibits high efficiency and low column bleed. These characteristics allow the determination of a large number of components in a single temperature-programmed electron-capture gas chromatographic analysis in less than 15 min. Recoveries of ten phenolics at the 20–200 ppb level are ca. 75% or greater.

Novel extraction device for the determination of chlorinated dibenzo-p-dioxins (CDDs) and dibenzofurans (CDFs) in matrices containing water

Abstract The efficient extraction of CDDs/CDFs from particulate matrices containing measurable amounts of water is complicated by the need to remove the water from the particles before beginning the extraction process. Traditionally, this has been done by pre-extracting the sample with a water miscible solvent such as isopropanol or by air drying for an extended period of time over various desiccants such as sulfuric acid or phosphorus pentoxide. These techniques can suffer from three possible problems: potential loss of analytes, accidental sample contamination, or an unacceptably long sample drying time. In response to these drawbacks, we have developed an extraction device that combines the simultaneous removal and measurement of water from a particulate sample with an exhaustive Soxhlet extraction of the dried particulates.

Analytical methodology of the Dow Chemical Company for the determination of selected chlorinated dibenzo-p-dioxins and dibenzofurans in stack gas effluent matrices: Part I: Full method for determination of tetra- through octa-chlorinated congener group total concentrations and “2378”-substituted isomers

Abstract This procedure permits the determination of CDDs/CDFs (chlorinated dibenzo-p-dioxins and dibenzofurans), over the range of congener groups having from four to eight chlorine substituents, in stack gas effluent samples containing both gaseous and particulate emissions. Stack gas samples are collected isokinetically from an operating process vent to the atmosphere using a United States Environmental Protection Agency (US EPA) modified Method 5 sample collection train. Analytes are recovered by subjecting the entire contents of a sampling train to extraction with benzene so as to produce a total-sample-crude-extract. An aliquot of the crude extract is fortified with [ 13 C 12 ]-labeled CDD/CDF isomer internal standards and subjected to a classical liquid-column chromatographic cleanup procedure that is designed to isolate a crude CDDs/CDFs fraction which contains all isomers having ≥4 chlorine substituents. Total congener group concentrations are determined by examination of this fraction via HRGC-LRMS (high resolution gas chromatographylow resolution mass spectrometry) techniques. When specific isomer determinations are required within congener groups bearing from 4 to 6-chlorine atoms, it is necessary to subject the remainder of the crude CDDS/CDFs fraction to further cleanup via a 2-dimensional HPLC (high performance liquid chromatography) technique which permits isolation of the desired analytes on the basis of compound specific retention indices. Final HRGC-LRMS examination of these fractions provides the necessary qualitative and quantitative data for each analyte.

Interlaboratory comparison of the determination of chlorinated dibenzo-p-dioxins and dibenzofurans according to regulatory methods EN 1948 and EPA 1613b.

Four laboratories participated in a collaborative study to determine differences in analytical results generated according to two different compliance methods, US EPA Method 1613b and European Union Method EN 1948 for the determination of chlorinated dibenzo-p-dioxins and dibenzofurans (CDD/CDFs). Various sample matrices containing the analytes at levels ranging from parts-per-quadrillion (ppq) to parts-per-billion (ppb) were used to illustrate differences and similarities between the two analytical methods. The choice of the sample matrices analyzed in this study was made to mirror many of the real-world samples that are of interest to Dow and also to test the laboratories on many different, complex matrices. For this reason, commercially available performance evaluation samples were not used. The study results indicate that the 1613b requirement for confirmation of analyte identity and concentration on a second, polar gas chromatographic column for 2378-tetrachlorodibenzofuran (TCDF) only may lead to quantitative results which are biased high compared to EN 1948 which additionally requires confirmation for all 2378-substituted tetra--through hexachlorodibenzo-p-dioxins and dibenzofurans.

Development of an HRGC-HRGC-LRMS system: Instrument design and performance data

Abstract Analytical Controls, Inc., can supply a Hewlett Packard Model 5890 high resolution gas chromatograph that is appropriately configured to accomplish fully automated, single-oven, 2-dimensional gas chromatography. As a portion of an extended research program dedicated to improving the capabilities of conventional instrumentation, we have developed and assembled the necessary components to permit the linkage of such a unit to a Hewlett Packard Model 5987A high resolution gas chromatograph-low resolution mass spectrometer (HRGC-LRMS). The results of this project have produced an instrument that can routinely conduct fully automated, dual-oven, 2-dimensional HRGC separations in conjunction with LRMS identification and detection for solutes eluting from the secondary analytical gas chromatograph. In this paper we will endeavor to describe this new analytical instrument and the techniques required to assemble it from commercially available resources. Preliminary evaluation and testing of the operational characteristics of the unit indicate that it may be a valuable tool for measuring compounds at trace concentrations in extremely complex matrices.

Micro-scale bromination procedure for synthesis of “2,3,7,8-substituted” brominated dibenzo-p-dioxins and dibenzofurans from [13C]-labeled precursors

Abstract Brominated dibenzo-p-dioxin and dibenzofuran (BDD/BDF) isomers, specifically having from one to three halogens located in the 2,3,7,8-substituent positions, that are [13C]-labeled for use as analytical internal standards in mass spectrometric methods are not yet commercially available. Based upon the current availability of [13C]-labeled dibenzo-p-dioxin and dibenzofuran (DD/DF) precursors, we have developed a simple and efficient synthetic procedure which produces brominated congeners that are predominantly substituted in the 2,3,7, and 8-positions. The gas/solid reaction of vaporized precursor and surface-supported iron (III) bromide occurs rapidly (seconds) at temperatures ≥ 240°C and can provide total product yields in the range of ∼30 to 50 mole % for initial precursor amounts between ∼1 μg and 10 mg. In this paper we shall describe the utility of this approach to produce ∼5 μg quantities of [13C12]-2,7-dibromodibenzo-p-dioxin (27-DBDD) and [13C12]-2,8-dibromodibenzo-p-dioxin (28-DBDD).

The determination of 2,3,7,8-tetrachlorodibenzo-p-dioxin in treated wastewater

Abstract A procedure has been developed for the determination of low levels (parts-per-trillion) of 2,3,7,8-tetrachlorodibenzo- p -dioxin in treated wastewater. A combination of cleanup steps on silica, alumina, and reactant modified adsorbents yields a relatively interference-free residue when examined by gas chromatography/mass spectrometry in the selected ion monitor (SIM) mode of operation.

Analytical methodology of the Dow Chemical Company for the determination of selected chlorinated dibenzo-p-dioxins and dibenzofurans in stack gas effluent matrices: Part II: Isomer method for determination of tetra- through octa-chlorinated congener group “2378”-substituted isomer concentrations

Abstract This procedure is a modification of the analytical method presented in Part I. It permits the determination of “2378”-substituted CDD and CDF isomers (chlorinated dibenzo-p-dioxins and dibenzofurans), over the range of congener groups having from four to eight chlorine substituents, in stack gas effluent samples containing both gaseous and particulate emissions. Stack gas samples are collected isokinetically from an operating process vent to the atmosphere using a United States Environmental Protection Agency (US EPA) modified Method 5 sample collection train. Analytes are recovered by subjecting the entire contents of a sampling train to extraction with benzene so as to produce a total-sample-crude-extract. An aliquot of the crude extract is fortified with [ 13 C 12 ]-labeled CDD/CDF isomer internal standards and subjected to a 2-dimensional HPLC (high performance liquid chromatography) cleanup procedure that is designed to isolate the seven “2378”-CDD and ten “2378”-CDF isomers into separate fractions from a single analysis aliquot. Final HRGC-LRMS (high resolution gas chromatography - low resolution mass spectrometry) examination of these fractions provides the necessary qualitative and quantitative data for each analyte.

Procedure and initial results for the determination of low part per quadrillion levels of 2,3,7,8-tetrachlorodibenzo-p-dioxin and 2,3,7,8-tetrachlorodibenzofuran in polyethylene

Abstract The Dow Chemical Company has undertaken the development of analytical methodology capable of detecting the presence of 2,3,7,8-tetrachlorodibenzo-p-dioxin (2378-TCDD) and 2,3,7,8-tetrachlorodibenzofuran (2378-TCDF) in low density polyethylene matrices at concentrations between the range of ∼50 to 100 parts per quadrillion (PPQ). Such detection capabilities are anticipated to permit reliable analyte quantitation at levels ranging from ∼200 to 400 PPQ. Recent progress has led to the emergence of an analytical procedure that appears capable of accomplishing the desired measurements. The qualitative identification and quantitative measurement of the analytes relies upon high resolution gas chromatography-low resolution mass spectrometry (HRGC-LRMS). This paper describes the current state of the analytical procedure and presents preliminary data for its application to low density polyethylene believed to be typical of that produced by Dow Chemical.