A1 Spmdwater Partition Coefficients

Literature values of SPMD-water partition coefficients (Ksws) should be used with caution. Different units of Ksw are generated when the concentrations in SPMD and water are expressed on a mass basis (e.g., ng g-1) or a volume basis (e.g., ng mL-1). Depending on the choice of concentration units, Ksw values will have units of g g-1, mL mL-1, or mL g-1 ,or Ksw values are given as dimensionless numbers in the former two cases. Care should be taken to distinguish between the different versions of...

Appendix B Spmd Bibliography

Over the last decade, the growth in SPMD research and applications has been remarkable. Reports on this work have been in the form of graduate degree (masters and Ph.D.) theses, abstracts from presentations, laboratory reports, journal articles and book chapters. Herein, we provide the reader with a list of SPMD related peer-reviewed journal articles and book chapters. However, we do not claim that this list is complete and apologize in advance to authors of articles not included. In light of...

Uptake Models

In this section we focus on solute exchange between SPMDs and water, but the general scheme can be easily extended to vapor exchange between SPMDs and air. Before going into details on the mathematical formulation of the exchange kinetics between SPMDs and the sample medium, it is instructive to have a look at the successive transport resistances that dissolved contaminants must overcome to be absorbed by exposed SPMDs. A few mm from the SPMD surface, all transport is dominated by eddy...

Mass Transfer Coefficient MTC Model

The second type of model is a mass-transfer coefficient (MTC) model, which is based on a mathematical description of solute-mass transfer through sequential but distinct physical environments (phases or regions). In the case of SPMD exposures, these environments include the WBL, the biofilm (not always present), the membrane, and the triolein. The MTC (k) can be viewed as the velocity (e.g., cm s-1) of a solute moving through a region, and k is equivalent to D 8, where D is the diffusion...

Similarity of Uptake Rate Constants

Meadows et al. (1998) conducted a 28 d exposure of brown trout (Salmo trutta), standard SPMDs and hexane filled dialysis bags (Sodergren, 1987) to spring water (total organic carbon < 1 mg L-1) contaminated with PCBs. Trout were not fed during the exposure, and temperature and flow conditions remained constant throughout the exposure. A good correlation (r2 0.89) was found between the uptake rate constants (ku Fs) for whole body trout and the uptake rate constants Figure 7.3 Comparison of...

Air Sampling Rates

In a number of field studies, sampling rates were obtained by parallel deployment of SPMDs and high-volume active air samplers (HiVols) for PCBs (Petty et al., 1993 Prest et al., 1995 Ockenden et al., 1998 Shoeib and Harner, 2002), and polychlorinated naphthalenes (Shoeib and Harner, 2002). Lohman et al. (2001) reported sampling rates of PAHs and PCDDs PCDFs that were based on SPMD and HiVol data obtained during different periods of the year. Laboratory-derived sampling rates have been reported...

Study Considerations

Before deploying SPMDs, it is important that users are aware of a number of study considerations and quality control (QC) issues. Some of the QC issues apply to environmental sampling in general, whereas some are specifically related to SPMDs and to a few other passive samplers. For example, SPMDs generally have relatively large surface areas (e.g., 460 cm2 cm-3 of triolein) to enhance uptake rates of solutes or vapor phase chemicals. Thus, special care must be used to prevent contamination of...

Dissipation Of Performance Reference Compounds PRCs

In order to assess an analyte's in situ SPMD-water exchange kinetics, performance reference compounds (PRCs as described in Chapter 1) are added to SPMD triolein prior to an exposure (Ellis et al., 1995 Booij et al., 1998 Ockenden et al., 2001 Huckins et al., 2002a). To use this approach, the investigator must be sure that the PRCs do not occur in the environment (e.g., certain non-labeled or native compounds such as PCB congeners 14, 29, 50, and a variety of compounds labeled with deuterium,...

References

Giesy, J.P. Jones, P.D. Verbrugge, D.A. 1991, Bioassay-derived 2,3,7,8-tetrahlorodibenzo-p-dioxin equivalents in the flesh and eggs of Lake Michigan Chinook Salmon and possible implications for reproduction. Can. J. Fish. Aquat. Sci. 48 1685-1690. Bailey, R.E. 1957, The effect of estradiol on serum calcium, phosphorus, and protein of goldfish. J. Exp. Zool. 136 455-469. Beauvais, S.J. 1997, Factors Affecting Cholinesterase in Aquatic Animals. Ph.D. Thesis, Iowa State...

Active Sampling Methods for Water and

Active sampling techniques represent the most widely used approach for the collection and extraction or trapping of contaminant residues in water. Active sampling refers to those methods that require physical intervention or external energy input for sample collection and or residue extraction or trapping. Often, samples are excised or removed (i.e., grab sampling) from the exposure medium before residues are extracted. Traditionally, grab samples of water were nearly always extracted with...

SPMDProcess Blanks

This type of QC blank consists of a subset of SPMDs, made just prior to initiation of the analysis of an SPMD sample set. Operationally, the only difference between SPMD-process blanks and SPMD-fabrication blanks is the time of preparation and that the SPMD-process blanks are not subjected to storage, but are immediately processed and analyzed along with the environmentally exposed SPMDs. Use of this type of blank is generally limited to laboratories that assemble SPMDs. If the numbers of...

Potential Effects Of Dissolved Organic Carbon Doc On Spmd Calibration Data

Mass Dissolved And Temperature

Because SPMD sampling rates are independent of chemical concentration, the attenuation of dissolved phase concentrations by DOC including colloids or particulate organic carbon POC particle size gt 0.45 m should have no measurable effect on actual analyte Rs values. In practice, the fractional amount of chemical sorbed to DOC can affect the accuracy of SPMD calibration experiments, which in turn can affect SPMD-derived estimates of dissolved environmental concentrations. Even in the laboratory,...

Passive Sampler Fundamentals And Terminology

Until the advent of SPMDs and solid phase microextraction SPME fibers, passive sampling devices were generally limited to integrative diffusion or permeation samplers Fowler, 1982 , with engineered barriers that control uptake rates. The engineered rate-limiting barriers of these classical samplers consist of a structural feature with stagnant air or water diffusional samplers or a nonporous polymeric membrane permeation samplers . In both cases, these barriers are designed to account for gt 90...

Microtox And Mutatox

Several investigators e.g., Huckins et al., 1996 Cleveland et al., 1997 Johnson, 1998 Johnson et al., 2004 Sabaliunas et al., 1999, 2000 Petty et al., Table 6.1 Toxicological Evaluation of Polycyclic Aromatic Hydrocarbons PAHs with Microtox Basic Test and Mutatoxa. Reprinted with permission from the American Petroleum Institute Huckins et al., 2002 Table 6.1 Toxicological Evaluation of Polycyclic Aromatic Hydrocarbons PAHs with Microtox Basic Test and Mutatoxa. Reprinted with permission from...

Estimation Of Exposure To Dioxinlike Compounds Using Sediments Caged Fish And Spmds

Gale et al. 1997 conducted a study in the Saginaw River, MI, USA to compare the SPMD method of water sampling with sediment-based and caged fish based methods for assessing exposure to dioxin-like compounds. More specifically, the targeted compounds were planar halogenated hydrocarbons PHHs , which consisted of planar PCBs, polychlorinated dibenzo-p-dioxins PCDDs , and polychlorinated dibenzofurans PCDFs . The list of target compounds was expanded to include polychlorinated dibenzothiophenes...

Using Spmds In Conjunction With Bioassays And Chemical Analysis To Characterize Toxic Pollutants

Lake Shkodra Skadar is the largest lake in the Balkan region and is located on the border between Albania and Montenegro. Due to the broad array of rare or endangered plant and animal species it supports, the lake and the extensive associated wetlands have been designated a Ramsar site. The lake is also the focus of an international cooperative investigation by a diverse team of researchers from Albania, Serbia and Montenegro, Germany, Austria and the UK, concerned with the possible detrimental...

Passive Sampler Development

In this work, we define passive samplers as human-made devices where sample collection and residue extraction occur simultaneously in a completely passive manner. The sampling or concentration process is mediated by the diffusion of chemicals from a matrix where chemical fugacity or potential is high to a matrix receiving medium or sorbent where chemical fugacity or potential is low. Three requirements must be met to derive reasonable estimates of ambient concentrations of analytes from their...