Trace organic environmental sampling

Throughout this book the use of a number of standard analytical samples is recommended in order that practical experience may be gained on substances of known composition. In addition, standard reference materials of environmental samples for trace analysis are used for calibration standards, and pure organic compounds are employed as standard materials for elemental analysis. 

Wise SA (1993) Standard reference materials for the determination of trace organic constituents in environmental samples. In Barcelo D, ed. Environmental Analysis Techniques, Applications and Quality Assurance, pp 403-446. Elsevier Science Publishers, Amsterdam, The Netherlands. Wise SA, and Schantz MM (1997) Standard reference materials for the determination of trace organic contaminants in environmental samples. In Clement R and Siu M, eds. Reference Materials for Environmental Analysis Making and Using Them, pp 143-186. Lewis Publishers, Boca Raton, FL. 

A wide range of analytical techniques have been developed in order to identify the organic contaminants often present at trace levels in complex environmental samples such as wastewaters. These techniques mainly use gas chromatography (GC) and liquid chromatography (LC). 

Huckins, J.N. Petty, J.D. Orazio, C.E. Zajicek, J.L. Gibson, V.L. Clark, R.C. Echols, K.R. 1994, Semipermeable Membrane Device (SPMD) Sampling Rates for Trace Organic Contaminants in Air and Water. 15th Annual meeting of Society of Environmental Toxicology and Chemistry Denver, CO. Abstract MBOl. 

Friant, S.L. and Suffet, I.H. Interachve effects of temperature, salt concentration, and pH on head space analysis for isolahng volatile trace organics in aqueous environmental samples. Anal. Chem., 51(13) 2167-2172, 1979. 

High-Performance Liquid Chromatography for Determination of Trace Organic Compounds in Aqueous Environmental Samples... 

In this chapter, the current and future capabilities of HPLC for the determination of trace organic compounds in aqueous environmental samples will be assessed. This assessment will include approaches to sample cleanup or analyte isolation for those species likely to be candidates for analysis by HPLC. Column technology, as it contributes to the use of HPLC for trace organic analyses, will be surveyed. Finally, detection of the compounds eluting from the system will be examined. The ultimate detector will always adequately identify and measure the compounds of interest. 

Graham and Garrison (17) evaluated on-line trace enrichment for the determination of trace organic compounds in aqueous environmental samples. These workers were primarily interested in nonvolatile and thermally labile compounds that were not readily analyzed by GC methodology. A 2-mm i.d. X 70-mm long stainless steel precolumn was packed with 30-75 pm diameter octadecyl-derivatized silica. This precolumn was substituted for the sample loop in a conventional, high-pressure, six-port valve. Water samples, 10-100 mL, were pumped directly on the precolumn. After loading, the valve was switched to... 

In the past 5 years the frequency of reports on the use of HPLC technology for the determination of trace organic compounds in aqueous environmental samples has been steadily increasing. Many innovative approaches to sample cleanup and analyte isolation have been reported. Reversed-phase separation, with its many mobile-phase adaptations, has been and continues to be the most popular HPLC separation mode. The development of fast columns and microbore columns should provide optimal configurations for particular applications. The operating characteristics of microbore columns also make... 

An attempt has been made to survey the current status of technology in HPLC as it applies to the analysis of trace organic compounds in aqueous environmental samples. No doubt, some developments relative to this topic have been overlooked, but the overall assessment should provide a glimpse of what has been done and also of what is possible. 

Early studies using resins for isolation and analysis of trace organics, such as pesticides, PCBs, and organic acids, from small volumes of water showed excellent recovery and the potential of easy application to environmental samples. Isotherm studies in distilled water were used to define the sampling parameters for quantitative analysis of these compounds. Later, studies using resin samplers for large-volume environmental samples were extrapolated from the early low-volume resin work of Junk et al. (5,14) and Thurman et al. (27) (see Table I). 

Chemical and biological analyses of trace organic mixtures in aqueous environmental samples typically require that some type of isolation-concentration method be used prior to testing these residues the inclusion of bioassay in a testing scheme often dictates that large sample volumes (20-500 L) be processed. Discrete chemical analysis only requires demonstration that the isolation technique yields the desired compounds with known precision. However, chemical and/or toxicological characterization of the chemical continuum of molecular properties represented by the unknown mixtures of organics in environmental samples adds an extra dimension of the ideal isolation technique ... 

Zielinska, B. and Fujita, E. (1994) Organic gas sampling, in Environmental Sampling For Trace Analysis (ed. B. Markert), VCH Verlagsgesellschaft, Weinheim, Germany. 

Similarly, many xenobiotics, such as pesticides, polynuclear aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), plasticizers, phenols, and some other dmg residues, are also toxic even at trace levels present in the earth s ecosystem [5-7], Without analytical techniques capable of detecting them at nanolevels, we assume the absence of these pollutants in the environment, while these notorious pollutants accumulate in our body tissues resulting in various diseases and side effects such as carcinogenesis and failure of many vital body organs including the kidney, liver, and heart [8-11]. Under such situations, it is essential to have analytical techniques that can detect dmgs, pharmaceuticals, and xenobiotics in biological and environmental samples at very low concentrations. 

Coquart, V. and M.C. Hennion (1991). Interference removal in the organic trace-level analysis of aqueous environmental samples by online liquid chromatographic preconcentration techniques with two precolumns. J. Chromatogr., 553 329-343. 

Koh, C.H., Khim, J.S., Villeneuve, D.L., Kannan, K., Giesy, J.P., 2002. Analysis of trace organic contaminants in environmental samples from Onsan Bay, Korea. Environ. Toxicol. Chem. 21, 1796-1803. 

Stir bar sorptive extraction (SBSE), an approach theoretically similar to SPME, was recently introduced [141] for the trace enrichment of organic compounds from aqueous food, biological, and environmental samples. A stir bar is coated with a sorbent and immersed in the sample to extract the analyte from solution. To date, reported SBSE procedures were not usually operated as exhaustive extraction procedures however, SBSE has a greater capacity for quantitative extraction than SPME. The sample is typically stirred with the coated stir bar for a specified time, usually for less than 60 minutes, depending on the sample volume and the stirring speed, to approach equilibrium. SBSE improves on the low concentration capability of in-sample solid-phase microextraction (IS-SPME). 

Another example of ultrasound use is leaching of organic impurities from different kinds of samples. The main analytes of interest are PAHs, which are widespread in soil, sediment, dust, and particulate samples [55]. USE is recommended as a fast, efficient, and direct environmental sample preparation method for determination of PCBs, nitrophenols, pesticides, or polymer additives. Organometallic and biologically active compounds (such as vitamins A, D, and E) present in samples in trace quantities, can be extracted from animal and plant tissues with the aid of ultrasonic wave energy [59]. Table 6.6 presents some typical applications of USE in trace analysis of biological and environmental samples [60]. 

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