This article provides a review of the routine methods currently utilized for total naphthenic acid analyses. There is a growing need to develop chemical methods that can selectively distinguish compounds found within industrially derived oil sands process affected waters (OSPW) from those derived from the natural weathering of oil sands deposits. Attention is thus given to the characterization of other OSPW components such as oil sands polar organic compounds, PAHs, and heavy metals along with characterization of chemical additives such as polyacrylamide polymers and trace levels of boron species. Environmental samples discussed cover the following matrices: OSPW containments, on-lease interceptor well systems, on- and off-lease groundwater, and river and lake surface waters. There are diverse ranges of methods available for analyses of total naphthenic acids. However, there is a need for inter-laboratory studies to compare their accuracy and precision for routine analyses. Recent advances in high- and medium-resolution mass spectrometry, concomitant with comprehensive mass spectrometry techniques following multi-dimensional chromatography or ion-mobility separations, have allowed for the speciation of monocarboxylic naphthenic acids along with a wide range of other species including humics. The distributions of oil sands polar organic compounds, particularly the sulphur containing species (i.e., OxS and OxS2) may allow for distinguishing sources of OSPW. The ratios of oxygen- (i.e., Ox) and nitrogen-containing species (i.e., NOx, and N2Ox) are useful for differentiating organic components derived from OSPW from natural components found within receiving waters. Synchronous fluorescence spectroscopy also provides a powerful screening technique capable of quickly detecting the presence of aromatic organic acids contained within oil sands naphthenic acid mixtures. Synchronous fluorescence spectroscopy provides diagnostic profiles for OSPW and potentially impacted groundwater that can be compared against reference groundwater and surface water samples. Novel applications of X-ray absorption near edge spectroscopy (XANES) are emerging for speciation of sulphur-containing species (both organic and inorganic components) as well as industrially derived boron-containing species. There is strong potential for an environmental forensics application of XANES for chemical fingerprinting of weathered sulphur-containing species and industrial additives in OSPW.
Recent worldwide surveys have not only established incomplete removal of pharmaceuticals and personal care products (PPCPs) by sewage treatment plants, but also their presence in surface waters receiving treated sewage effluent. Those aquatic systems where sewage effluent dominates flow are thought to be at the highest risk for ecosystem level changes. The city of Regina, Saskatchewan, Canada (population 190,400) treats its sewage at a modern tertiary sewage treatment facility located on Wascana Creek. The Wascana Creek hydrograph is dominated by one major event: spring snow melt. Thereafter, creek flow declines considerably and in winter treated sewage effluent makes up almost 100% of stream flow. Four water surveys conducted on the creek from winter 2005 to spring 2007 indicated that PPCPs were always present, in nanogram and sometimes microgram per liter concentrations downstream of the sewage treatment plant. This mixture included antibiotics, analgesics, antiinflammatories, a lipid regulator, metabolites of caffeine, cocaine and nicotine, and an insect repellent. Not surprisingly, concentrations of some PPCPs were highest in winter. According to hazard quotient calculations and homologue presence, ibuprofen, naproxen, gemfibrozil, triclosan, erythromycin, trimethoprim, and sulfamethoxazole were present in Wascana Creek at concentrations that may present a risk to aquatic organisms. The continual exposure to a mixture of pharmaceuticals as well as concentrations of un-ionized ammonia that far exceed Canadian and American water quality guidelines suggests that Wascana Creek should be considered an ecosystem at risk. Although the Wascana Creek study is regional in nature, the results highlight the considerable risks posed to aquatic organisms in such effluent-dominated ecosystems.
Glyphosate [N-(phosphonomethyl)glycine] is the active ingredient of several herbicide products first registered for use in 1974 under the tradename Roundup. The use of glyphosate-based herbicides has increased dramatically over the last two decades particularly in association with the adoption of glyphosate-tolerant crops. Glyphosate has been detected in a range of surface waters but this is the first study to monitor its fate in prairie wetlands situated in agricultural fields. An ephemeral wetland (E) and a semi-permanent wetland (SP) were each divided into halves using a polyvinyl curtain. One half of each wetland was fortified with glyphosate with the added mass simulating an accidental direct overspray. Glyphosate dissipated rapidly in the water column of the two prairie wetlands studied (DT(50) values of 1.3 and 4.8 d) which may effectively reduce the impact of exposure of aquatic biota to the herbicide. Degradation of glyphosate to its major metabolite aminomethylphosphonic acid (AMPA) and sorption of the herbicide to bottom sediment were more important pathways for the dissipation of glyphosate from the water column than movement of the herbicide with infiltrating water. Presently, we are not aware of any Canadian guidelines for glyphosate residues in sediment of aquatic ecosystems. Since a substantial portion of glyphosate entering prairie wetlands will become associated with bottom sediments, particularly in ephemeral wetlands, guidelines would need to be developed to assess the protection of organisms that spend all or part of their lifecycle in sediment.
Clopyralid (3,6-dichloropicolinic acid), picloram (4-amino-3,5,6-trichloropicolinic acid), and silvex (2-(2,4,5-trichlorophenoxy)propionic acid) at concentrations of 0.0100 μg/g in 14 fortified Alberta soils were determined by calcium hydroxide−water extraction and gas chromatography measurement. Precision of analyses was 1−13%. The herbicide recoveries from the soils with two different fortification procedures were compared. The relationships between recoveries and soil components were examined and discussed. Results from fortified soils, which were extracted immediately following spiking of herbicides, indicated clopyralid recovery of 95.2 ± 6.7% and was independent of the organic matter (0.4−5.3%), clay (3.6−44.2%), sand (16.5−94.1%), or iron (3908−22 455 μg/g) content in the soil. However, picloram and silvex recoveries (58.0−97.8%) were dependent on soil properties with a significant negative trend for being affected by the organic matter content of the soil. Their recoveries decreased with increasing organic matter content of the soil. Detection limits of 0.0025−0.0500 μg/g were herbicide and soil dependent. Results from fortified soil slurries which were extracted after 2−14 days of drying indicated lower herbicide recoveries. The different recoveries from two fortification procedures were discussed in relation to herbicide solubilities, soil-to-water partition coefficients, sorption/desorption, and possible degradation. Keywords: Clopyralid; picloram; silvex; soil components; organic matter content; extraction; calcium hydroxide−water; low concentration; gas chromatography; determination
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