Identifying Future Drinking Water Contaminants (1999) / Chapter Skim
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7 New and Emerging Analytical Techniques for the Detection of Organic Contaminants in Water
7 New and Emerging Analytical Techniques for the Detection of Organic Contaminants in Water
Pages 120-135
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From page 120... ...
Even though good mass spectra are obtained from a majority of the contaminants that are detected, most remain unidentified and/or unquantified because of a lack of reference spectra and/or reference compounds. The information that can be deduced from the mass spectra maY be sufficient to oronose structures using spectral determinations.
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From page 121... ...
The lowest MCLs are in the tow nanogram per liter range, and it is evident that target concentrations for detailed characterizations of individual compounds should be in the low nanogram per liter range as well. This paper reviews new and emerging analytical approaches for the analysis of aqueous environmental samples.
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From page 122... ...
polyethoxylates, octyland nonylphenol ethoxycarboxylates, linear alkyl benzene sulfonates Aromatic sulfonates, chelating agents, amino carboxylic acids Xylenes, aldehydes, disulfides, chlorophenol Dialkyl ether, alcohol, methyl tertiary butyl ether Trihalomethanes, haloacetic acids and/or improve identification or detection. Because reference compounds for most contaminants are not available, synthesis is often necessary for structure verification and the development of rapid detection and quantification procedures.
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From page 123... ...
is an important analytical factor since it influences the stability of Me complex and its spectroscopic properties. New and Emerging Analytical Techniques for the Detection' of Organic Contaminants in Water 123
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From page 124... ...
As this method has been shown to be successful in retaining a substantial fraction of the larger organic molecules present, retention of smaller organic molecules as well as inorganic components is dependent on membrane pore size and charge. A tradeoff emerges, with smaller pore sizes increasing the fraction of organic matter isolated corresponds to increasing inorganics retention.
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From page 125... ...
or small molecules with multiple functional groups. The derivatization chemistry utilizes an agent that reacts selectively with the functional group to form a stable product that can be separated from the water matrix by extraction or sorption, from other analyses by chromatography, detected by chromatographic detectors, or identified by mass spectrometry.
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From page 126... ...
~19961. INSTRUMENTAL ANALYSIS Fractionation and Separation Conventional fractionation and separation involve preparative column chromatography, followed by GC or high-performance liquid chromatography.
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The analyses progressed in New and Emerging Analytical Techniques for the Detection of Organic Contaminants in Water 127
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From page 128... ...
The extracts were analyzed using a GC/MS system in the multiple ion detection mode. Concentrations of clofibric acid artificially recharged 128 Identifying Future Drinking Water Contaminants
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From page 129... ...
(1997) reported that 45 pesticides, representing 15 compound classes and possessing a wide range of polarity, were quantif~ed using SPE followed by LC/ESP/MS.
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From page 130... ...
Mangiapan and co-workers (1997) report quantification of arachlor and its degradation products by using SPE followed by GC/MS.
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From page 131... ...
These compounds were initially captured by utilizing cartridge SPE and then separated and quantified using liquid chromatography. Industrial Additives and Chelating Agents This compound class includes chemically diverse compounds that are used as additives in plastic or concrete, foundry mold, as tanning agents.
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From page 132... ...
The target concentrations for trace organics are being pushed from the microgram to the nanograms per liter range. The trend to lower detection limits is driven by the low MCEs and the potency of some endocrin disruptors.
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1997. Simultaneous determination of neutral and acidic pesticides in natural water at the low nanogram per liter range.
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From page 134... ...
1997. Monitoring long-chain intermediate products from the degradation of linear alkylbenzene sulfonates in the marine environment by solid-phase extraction followed by liquid chromatography/ionspray mass spectrometry 31 :504-510.
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1997. Drugs in water: Analysis at the part-perbillion level using direct supercritical fluid extraction of aqueous samples coupled on-line with ultraviolet-visible diode-array liquid chromatography-mass spectrometry.
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