A regioselective synthesis of 6-alkyl- and 6-aryluracils was developed by the dimerization of 3-alkyl- and 3-aryl-2-propynamides promoted by either Cs2CO3 or K3PO4. A range of 3-aryl-2-propynamides, with both electron-deficient and electron-rich 3-aryl substituents, were successfully reacted in high yields. Cs+ acts as a soft Lewis acid to polarize the carbon–carbon triple bond, and solid K3PO4 interacts with carbonyl oxygen, promoting intermolecular nucleophilic attack by the only weakly nucleophilic amide nitrogen. Experiments were conducted to support the proposed mechanism.

•Raw and magnetized Douglas fir biochar was used to remediate water.•Salicylic acid, 4-nitroaniline, benzoic acid and phthalic acid were adsorbed from aqueous solutions.•The Douglas fir biochars had far higher adsorption capacities than the other biochars studied.•They also had far faster uptake kinetics of the analytes.Biochar was produced from the fast pyrolysis of Douglas fir (DFBC). Magnetic biochar (MDFBC) was prepared by magnetite (Fe3O4) precipitation onto the biochar’s surface from an aqueous Fe3+/Fe2+ solution upon NaOH treatment. The resulting MDFBC was used to remove 4-nitroaniline (4NA), salicylic acid (SA), benzoic acid (BA) and phthalic acid (PA) from water. The surface chemistry and composition of the MDFBC were examined by SEM, SEM-EDX, TEM, PZC, XPS, XRD, elemental analysis, and surface area measurements. Batch sorption studies were carried out from pH 2 to 10 and adsorbate concentrations from 25 to 500 mg/L at 15, 25, 35 and 45 °C. MDFBC suspensions in the contaminated solutions were vortexed for two min and then magnetically removed. Remediated solutions were then analyzed using UV–Visible spectroscopy. The amounts of 4NA, SA, BA and PA adsorbed onto MDFBC was higher at low pH values and decreased with increasing pH. MDFBC sorption at 15, 25, 35 and 45 °C was evaluated using the Langmuir, Freundlich, Sips, Redlich–Peterson, and Toth adsorption isotherm models. Langmuir adsorption capacities at pH 5 and 45 °C for 4NA, SA, BA and PA were 114, 109, 90 and 86 mg/g, respectively. Thrice recycled MDFBC using extraction with methanol (5 × 10 mL) and water (10 mL) had 90% of the original adsorption capacities for 4NA, SA, BA and PA, respectively. The adsorption kinetics of MDFBC and DFBC were far faster than four other biochars (mixed feed, magnetized mixed feed, pinewood and magnetized switchgrass) and also faster than a commercial activated carbon. Equilibrium for MDFBC and its DFBC precursor was reached within 2 min, while the other biochars took between 8 and 20 h. The fast adsorption kinetics and high adsorption capacities of MDFBC could be advantageously employed in filtration devices, columns, or as shown here, in batch operations with stirring to speed adsorption, followed by magnetic separation of the adsorbent for regeneration.

Comprehensive two-dimensional gas chromatography (GC × GC) hyphenated with rapid quadrupole mass spectrometry was successfully used to develop a novel method for the determination of trace level estrogens in influent and effluent wastewater. Five estrogens used for the study were 17β-estradiol (βE2), 17α-estradiol (αE2), estrone (E1), 17α-ethynylestradiol (EE2) and estriol (E3). Two orthogonal columns and thermal modulation result in enhanced separation, while the rapid scanning quadrupole mass spectrometer gives high resolution peaks. Samples were extracted with Hydrophilic–Lipophilic Balance (HLB) cartridges and derivatized with N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) prior to analysis. The method uses a single extraction step and ng L−1 method detection limits were achieved using a relatively low sample volume of 500 mL. Elimination of additional cleanup steps make the method time effective. Furthermore, the method has less initial cost as the instrument is far less expensive than a tandem mass spectrometer. A parallel conventional gas chromatographic-mass spectrometric (GC/MS) study was carried out to compare the results. Detection limits were 2 to 4 times improved with the GC × GC over the GC/MS.

A novel approach is reported to quantify estrone (E1), 17β-estradiol (βE2), 17α-estradiol (αE2), estriol (E3), and 17α-ethynylestradiol (EE2) in storm water runoff and swine lagoon wastewater samples. A considerable amount of residue was collected when lagoon wastewater samples were centrifuged therefore both resulting residues and aqueous portions were analyzed separately. A modified Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) method was utilized to efficiently extract the target analytes in the residue. Aqueous portions were pre-concentrated using solid phase extraction (SPE). A simple liquid–liquid extraction in a test tube was carried out as a sample clean-up step after SPE. This approach is inexpensive and requires only 3 mL of organic solvent per analysis. The resulting extracts were further purified using a dispersive solid phase extraction (dSPE) technique (not required in storm water analyses). βE2 and E1 glucuronide and sulfate conjugates were also analyzed in the aqueous portions of the lagoon samples as well as in the storm water runoff samples. An enzymatic hydrolysis was performed prior to SPE to deconjugate conjugated estrogens. Samples were derivatized with dansyl chloride to enhance LC/MS/MS analytical sensitivity. Insignificant matrix effects (1–12%) were determined for the analyses of aqueous samples. Thus, matrix matched calibration curves were not required. Matrix effects for residue analyses ranged from 14 to 20%, requiring that matrix matched calibration curves be used for quantification. All developed methods gave 84–106% recoveries for free estrogens and 65–86% recoveries for estrogen conjugates. The LODs for lagoon wastewater and storm water analyses ranged from 0.9–2 ng L−1 and 0.3–0.5 ng L−1, respectively. The developed methods were validated by analyzing eighteen lagoon water samples and twenty six storm water samples in three replicates.

A novel approach is reported to quantify estrone (E1), 17β-estradiol (βE2), 17α-estradiol (αE2), estriol (E3), and 17α-ethynylestradiol (EE2) in storm water runoff and swine lagoon wastewater samples. A considerable amount of residue was collected when lagoon wastewater samples were centrifuged therefore both resulting residues and aqueous portions were analyzed separately. A modified Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) method was utilized to efficiently extract the target analytes in the residue. Aqueous portions were pre-concentrated using solid phase extraction (SPE). A simple liquid–liquid extraction in a test tube was carried out as a sample clean-up step after SPE. This approach is inexpensive and requires only 3 mL of organic solvent per analysis. The resulting extracts were further purified using a dispersive solid phase extraction (dSPE) technique (not required in storm water analyses). βE2 and E1 glucuronide and sulfate conjugates were also analyzed in the aqueous portions of the lagoon samples as well as in the storm water runoff samples. An enzymatic hydrolysis was performed prior to SPE to deconjugate conjugated estrogens. Samples were derivatized with dansyl chloride to enhance LC/MS/MS analytical sensitivity. Insignificant matrix effects (1–12%) were determined for the analyses of aqueous samples. Thus, matrix matched calibration curves were not required. Matrix effects for residue analyses ranged from 14 to 20%, requiring that matrix matched calibration curves be used for quantification. All developed methods gave 84–106% recoveries for free estrogens and 65–86% recoveries for estrogen conjugates. The LODs for lagoon wastewater and storm water analyses ranged from 0.9–2 ng L−1 and 0.3–0.5 ng L−1, respectively. The developed methods were validated by analyzing eighteen lagoon water samples and twenty six storm water samples in three replicates.

Comprehensive two-dimensional gas chromatography (GC × GC) hyphenated with rapid quadrupole mass spectrometry was successfully used to develop a novel method for the determination of trace level estrogens in influent and effluent wastewater. Five estrogens used for the study were 17β-estradiol (βE2), 17α-estradiol (αE2), estrone (E1), 17α-ethynylestradiol (EE2) and estriol (E3). Two orthogonal columns and thermal modulation result in enhanced separation, while the rapid scanning quadrupole mass spectrometer gives high resolution peaks. Samples were extracted with Hydrophilic–Lipophilic Balance (HLB) cartridges and derivatized with N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) prior to analysis. The method uses a single extraction step and ng L−1 method detection limits were achieved using a relatively low sample volume of 500 mL. Elimination of additional cleanup steps make the method time effective. Furthermore, the method has less initial cost as the instrument is far less expensive than a tandem mass spectrometer. A parallel conventional gas chromatographic-mass spectrometric (GC/MS) study was carried out to compare the results. Detection limits were 2 to 4 times improved with the GC × GC over the GC/MS.