RESEARCHWATCH
MEASUREMENTS Detecting herbicides The imidazolinones, a new class of herbicides used in a wide variety of agricultural applications, are low-use rate herbicides and therefore need to be measured in low parts per billion concentrations in soil. S. J. Stout and colleagues developed a new method to measure these compounds with decreased sample preparation time and improved sensitivity. The method incorporates microwave-assisted extraction, solid-phase extraction cleanup, and gas chromatography/ electron capture negative chemical ionization mass spectrometry analysis with selected ion monitoring. The authors averaged 92% recovery from four soil types at a fortification from 1 to 50 DDb with a 13% RSD They processed 12 samples for analin 2 h with an additional 30 min per sample for instrumental analysis (Anal Chem 1996 68 653-58)
QSARs for inorganics Although quantitative structureactivity relationships (QSARs) often have been used to predict environmental behavior of organic compounds, few such relationships exist for inorganic substances. M. C. Newman and J. T. McCloskey determined QSARs for eight divalent metals in the Microtox aquatic toxicity assay. Toxicities of Ca(II), Cd(II), Hg(II), Mg(II), Mn(II), Ni(II), Pb(II), and Zn(II) were correlated with decreasing acidity. Metal ion acidity is linked to the metal's affinity for binding to important biochemicals. The authors also were ctble to pre*dict metal interactions The results suggested that similar correlations may be possible for other aauatic toxicitv tests (Environ Toxicol Chem 1996 15 275-81)
Characterizing PAHs Characterization of polycyclic aromatic hydrocarbons (PAHs), carcinogenic compounds formed by incom-
Characterizing colloids Environmental colloids in soil are believed to play an important role in the geochemistry, transport, and bioavailability of contaminants. However, data are scarce because methods generally do not allow artifact-free isolation and characterization of colloidal materials. R. M. Burgess and co-workers assessed ultrafiltration and reverse-phase chromatography as methods for isolating marine sediment interstitial colloids. They found that reverse-phase chromatography was a suitable method for quantifying interactions between colloids and polychlorinated biphenyls (PCBs). Data were reproducible, and K values agreed with the literature. In contrast, ultrafiltration suffered from colloidal break-through problems and sorption of dissolvedphase PCBs to the filter. (Environ. Sci. Techno!..,his issue, ,923-32)
plete fuel combustion, has focused on die lower atomic weight species, which are more volatile. A. L. Lafleur and colleagues used atmospheric pressure chemical ionization mass spectrometry (APCI-MS) to greatiy extend the molecular weight range of PAHs that can be characterized. They developed two techniques: highperformance liquid chromatography (HPLC) combined witii APCI-MS and direct liquid introduction (DLI) combined with APCI-MS. Both used a heated nebulizer to introduce sample. The HPLC technique separated and analyzed PAHs up to molecular weights of higher weights were not achievable for the chromatography The DLI technique characterized PAHs at molecular weights between 400 and 2000 amu (/ Am Soc Mass Spectrom 1996 7 276-86)
POLICY Technology barriers N. Derzko examined barriers to sustainable development such as legal and regulatory restraints on environmental technologies. Status quo methodologies and programs, including die U.S. patent system and command-and-control, technologybased standards established under the Clean Air Act, hinder technological advancement. Derzko found that cost, time, and uncertainty determine whether new environmental technologies are developed and
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should be factored into future regulatory and legal agendas. She proposes establishing an environmental patent system, restructuring environmental permits, and using treaties as a means to propel the development and use of environmental technologies. (Harvard Environ. Law Review 1996, 20, 3-59)
RECYCLING Laser-printed paper Increased demand for recycled paper products has resulted in an increased need for high-quality recycled fiber. Office paper contains such fiber, but laser-printed toners are difficult to remove by conventional de-inking. O. U. Heise and co-workers investigated industrialscale, enzymatic de-inking. Pulp strength was maintained compared witii a conventional control but oo~ ticcil properties were mixed. Effluent oxygen demand was similar to the control, while toxicity reportedly decreased. Results indicated that enzymatic de-inking is a promising alternative for recycling mixed office waste papers (TAPPIJ 1199 77 207-12)
REMEDIATION Irradiating dioxins Dioxin in soil is a significant remediation problem. Current techniques
VOL. 30, NO. 6, 1996 / ENVIRONMENTAL SCIENCE & TECHNOLOGY / NEWS • 2 3 3 A
