The continuous release of pharmaceuticals and personal care products (PPCPs) into freshwater systems impacts the health of aquatic organisms. This study evaluates the concentrations and bioaccumulation of PPCPs and the selective uptake of antidepressants in fish from the Niagara River, which connects two of the North American Great lakes (Erie and Ontario). The Niagara River receives PPCPs from different wastewater treatment plants (WWTPs) situated along the river and Lake Erie. Of the 22 targeted PPCPs, 11 were found at part-per-billion levels in WWTP effluents and at part-per-trillion levels in river water samples. The major pollutants observed were the antidepressants (citalopram, paroxetine, sertraline, venlafaxine, and bupropion, and their metabolites norfluoxetine and norsertraline) and the antihistamine diphenhydramine. These PPCPs accumulate in various fish organs, with norsertraline exhibiting the highest bioaccumulation factor (up to about 3000) in the liver of rudd (Scardinius erythrophthalmus), which is an invasive species to the Great Lakes. The antidepressants were selectively taken up by various fish species at different trophic levels, and were further metabolized once inside the organism. The highest bioaccumulation was found in the brain, followed by liver, muscle, and gonads, and can be attributed to direct exposure to WWTP effluent.

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A cloud-point extraction (CPE) method using Triton X-114 non-ionic surfactant was developed for the extraction and preconcentration of carbamate insecticide residues (i.e., methomyl, propoxur, carbofuran, carbaryl, isoprocarb, and promecarb) in fruit samples. The optimum conditions of CPE were 1.5% (w/v) Triton X-114, 7.0% (w/v) NaCl and 20 min equilibrated at 45 degrees C. The surfactant-rich phase was then analyzed by reversed-phase high-performance liquid chromatography with ultraviolet detection at 270 nm, under gradient separation using methanol and 0.1% (v/v) acetic acid. Under the study conditions, six carbamate insecticides were successfully separated within 27 min. Good reproducibility was obtained with the relative standard deviation of <3% for retention time and <9% for peak area. Limits of detection in the studied fruit samples were in the range of 0.1-1.0 mg kg(-1). No carbamate insecticides were detected in the studied fruit samples. The high recoveries of the spiked fruit samples were obtained in the range 80.0-107%. The CPE method has been shown to be a potential useful methodology for the preconcentration of the target analytes, with a preconcentration factor of 14. Moreover, the method is simple, has high sensitivity, consumes much less solvent than traditional methods, and is environmental friendly.

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A novel spectrophotometric reaction system was developed for the determination of nitrite, as well as nitrate, in water samples, and was applied to a flow injection analysis.The spectrophotometric flow-injection system coupled with a copperised cadmium reductor column was proposed. The detection was based on the nitrosation reaction between nitrite ion and phloroglucinol (1,3,5-trihydroxybenzene), a commercially available phenolic compound.Sample injected into a carrier stream was split into two streams at the Y-shaped connector.One of the streams merged directly and reacted with the reagent stream: nitrite ion in the samples was detected. The other stream was passed through the copperised cadmium reductor column, where the reduction of nitrate to nitrite occurred, and the sample zone was then mixed with the reagent stream and passed through the detector: the sum of nitrate and nitrite was detected. The optimized conditions allow a linear calibration range of 0.03-0.30 μg NO 2 --N/ml and 0.10-1.00 μg NO 3 --N/ml. The detection limits for nitrite and nitrate, defined as three-times the standard deviation of measured blanks, are 2.9 ng NO 2 --N/ml and 2.3 ng NO 3 --N/ml, respectively. Up to 20 samples can be analysed per hour with a relative * Corresponding author. Tel.: +81-86-251-7846 E-mail address: motomizu@cc.okayama-u.ac.jp (S. Motomizu) standard deviation of less than 1.5%. The proposed method could be applied successfully to the simultaneous determination of nitrite and nitrate in water samples.