Standard Solid-phase Extraction Research Articles

Simultaneous Determination of Multiple Contaminants in Chicken Liver Using Dispersive Liquid-Liquid Microextraction (DLLME) Detected by LC-HRMS/MS

Simultaneous determination of a mixture of food contaminants, including pesticides, sulphonamides, fluoroquinolones, anthelmintics, and aflatoxin B1, in solid biological samples (chicken liver) by dispersive liquid-liquid microextraction/liquid chromatography-high resolution mass spectrometry (DLLME/LC-HRMS) is presented. Previous work focused on the application of DLLME to single-class contaminants. In this work, the DLLME extraction method has been extended to complex multiresidues in the biological matrix. The first part of this study was the selection of an appropriate solvent that enabled the dissolution of analytes from the chicken livers. The matrix-matched calibration curves showed good linearity in the range 0.5–50.0 µg kg−1 for aflatoxin B1 and 50–500 µg kg−1 for pesticides, fluoroquinolones, sulphonamides, and anthelmintics, with a coefficient of determination (R2) values of 0.9916–0.9967. The mean recoveries were in the range of 80.4–96.3%, and the relative standard deviation (RSD) values were in the range of 1.53–8.98%. The limit of detection (LOD) and the limit of quantification (LOQ) values were 0.03 µg kg−1 and 0.09 µg kg−1, respectively, for aflatoxin B1, and for pesticides, fluoroquinolones, sulphonamides, and anthelmintics, they were in the range of 0.011–1.197 µg kg−1 and 0.150–2.579 µg kg−1, respectively. The developed method was compared with the standard solid phase extraction (SPE) method, and there was no significant difference between the two methods.

Molecular Dynamic Study of Mechanism Underlying Nature of Molecular Recognition and the Role of Crosslinker in the Synthesis of Salmeterol-Targeting Molecularly Imprinted Polymer for Analysis of Salmeterol Xinafoate in Biological Fluid.

The rational preparation of molecularly imprinted polymers (MIPs) in order to have selective extraction of salmeterol xinafoate (SLX) from serum was studied. SLX is an acting β-adrenergic receptor agonist used in the treatment of asthma and has an athletic performance-enhancing effect. Molecular dynamics were used for the simulation of the SLX-imprinted pre-polymerization system, to determine the stability of the system. The computational simulation showed that SLX as a template, 4-hydroxyethyl methacrylate (HEMA) as a monomer, and trimethylolpropane trimethacrylate (TRIM) as a crosslinker in mol ratio of 1:6:20 had the strongest interaction in terms of the radial distribution functional. To validate the computational result, four polymers were synthesized using the precipitation polymerization method, and MIP with composition and ratio corresponding with the system with the strongest interaction as an MD simulation result showed the best performance, with a recovery of 96.59 ± 2.24% of SLX in spiked serum and 92.25 ± 1.12% when SLX was spiked with another analogue structure. Compared with the standard solid phase extraction sorbent C-18, which had a recovery of 79.11 ± 2.96%, the MIP showed better performance. The harmony between the simulation and experimental results illustrates that the molecular dynamic simulations had a significant role in the study and development of the MIPs for analysis of SLX in biological fluid.

CoolTip: Low-Temperature Solid-Phase Extraction Microcolumn for Capturing Hydrophilic Peptides and Phosphopeptides

Reversed-phase solid-phase extraction (SPE) techniques are commonly used for desalting samples before LC/MS/MS in shotgun proteomics. However, hydrophilic peptides are often lost during the desalting step under the standard SPE conditions. Here, we describe a simple protocol in which a stop-and-go extraction tip packed with a poly(styrene-divinylbenzene) copolymer disc is used at 4 °C during sample loading without any organic solvent. Using this method, which we designate as the CoolTip protocol, we identified 2.9-fold more tryptic peptides and 6.1-fold more tryptic phosphopeptides from HeLa lysates than the standard SPE protocol for hydrophilic peptides, with a mobile phase of less than 8% acetonitrile in LC/MS/MS. There was no decrease in the recovery of hydrophobic peptides. CoolTip also provided better quantitative reproducibility in LC/MS/MS analysis. We anticipate that this protocol will provide improved performance in many kinds of shotgun proteomics experiments.

Recent Materials Developed for Dispersive Solid Phase Extraction.

Solid phase extraction (SPE) is an analytical procedure developed with the purpose of separating a target analyte from a complex sample matrix prior to quantitative or qualitative determination. The purpose of such treatment is twofold: elimination of matrix constituents that could interfere with the detection process or even damage analytical equipment as well as enriching the analyte in the sample so that it is readily available for detection. Dispersive solid phase extraction (dSPE) is a recent development of the standard SPE technique that is attracting growing attention due to its remarkable simplicity, short extraction time and low requirement for solvent expenditure, accompanied by high effectiveness and wide applicability. This review aims to thoroughly survey recently conducted analytical studies focusing on methods utilizing novel, interesting nanomaterials as dSPE sorbents, as well as known materials that have been only recently successfully applied in dSPE techniques, and evaluate their performance and suitability based on comparison with previously reported analytical procedures.

Functionalization of Amberlite XAD-4 with 8-hydroxyquinoline chelator using aryldiazonium radical reaction and its application for solid phase extraction of trace metals from groundwater samples

<p>In this work, the aryldiazonium salts radical addition method has been used successfully to anchor 8-hydroxyquinoline (8-HQ) moieties onto the surface of Amberlite XAD-4 beads. The nitroaniline aryldiazonium salt was generated (in-situ) and covalently grafted onto Amberlite XAD-4 by aid of hypophosphorous acid as a catalyst to facilitate the anchorage of 8-HQ chelator making use of the conventional diazo coupling. The successfulness of the synthesized chelating resin was confirmed by (ATR-IR), (TGA) and (XPS). The risen was packed into cartridges and used with standard solid phase extraction (SPE) apparatus for the extraction of trace metals; Co (II), Ni (II) and Cu (II) from groundwater samples prior to their measurement by (ICP-MS). The resin exhibited more than 90% enhancement in capacity exchange relative to the plain Amberlite XAD-4. Under the optimum conditions the sorption capacity of the sorbent was 0.366, 0.265 and 0.328 (mM/g) for Co (II), Ni (II) and Cu (II) respectively. The sorbent showed efficient performance when applied for SPE of trace metals from groundwater real samples from AlMadinah AlMumnawarah, Saudi Arabia.</p>

Discussion: Automated filtration or really just solid phase extraction

In this article, we discuss a recent publication by Casati et al. (2018) focusing on the sample preparation that is described for the analysis of phosphatidylethanols and whether or not their proposed method of ‘automated filtration’ and the advantages it brings is really just a standard solid phase extraction protocol.

Improved Reversible Cross-Linking-Based Solid-Phase RNA Extraction for Pathogen Diagnostics.

In this study, we developed an amine-functionalized, diatomaceous earth-based, dimethyl suberimidate assisted (ADD) system as a novel binding strategy to improve the solid-phase extraction method for rapid and simple purification of RNA from biological samples including human cells and pathogenic bacteria. This ADD system is based on reversible cross-linking reactions between RNA and the silica matrix. The formation of robust covalent bonds protects RNA from both the sufferance of washing steps and isolation with ribonuclease (RNase)-rich samples, leading to the extraction of higher quality RNA. This improved RNA extraction system integrated with quantitative real-time reverse transcription polymerase chain reaction (RT-qPCR) is evaluated for pathogen diagnostics. Compared to standard solid-phase extraction based commercial kits, this improved method shows highly enhanced sensitivity with 1000-fold higher sensitivity for human cells and 100-fold higher sensitivity for Brucella bacteria, according to the cycle threshold value of RT-qPCR. We envision that the ADD system can be tailored for commercial applications for RNA expression analysis in forensics studies, as well as for disease diagnostics in clinical applications.

Simultaneous determination of 41 multiclass organic pollutants in environmental waters by means of polyethersulfone microextraction followed by liquid chromatography-tandem mass spectrometry.

A new procedure using polyethersulfone (PES) microextraction followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis was developed in this work for the simultaneous determination of 41 multiclass priority and emerging organic pollutants including herbicides, hormones, personal care products, and pharmaceuticals, among others, in seawater, wastewater treatment plant (WWTP) effluents, and estuary samples. The optimization of the analysis included two different chromatographic columns and different variables (polarity, fragmentor voltage, collision energy, and collision cell accelerator) of the mass spectrometer. In the case of PES extraction, ion strength of the water, pH, addition of EDTA, and the amount of the polymeric material were thoroughly investigated. The developed procedure was compared with a previously validated one based on a standard solid-phase extraction (SPE). In contrast to the SPE protocol, the PES method allowed a cost-efficient extraction of complex aqueous samples with lower matrix effect from 120mL of water sample. Satisfactory and comparable apparent recovery values (80-119 and 70-131%) and method quantification limits (MQLs, 0.4-26 and 0.2-23ng/L) were obtained for PES and SPE procedures, respectively, regardless of the matrix. Repeatability values lower than 27% were obtained. Finally, the developed methods were applied to the analysis of real samples from the Basque Country and irbesartan, valsartan, acesulfame, and sucralose were the analytes most often detected at the highest concentrations (51-1096ng/L). Graphical abstract Forty-one multiclass pollutant determination in environmental waters by means of PES/SPE-LC-MS/MS.

Oxidation of Selected Phenothiazine Drugs During Sample Preparation: Effects of Varying Extraction Conditions on the Extent of Oxidation.

Characterization of degradation products formed from selected phenothiazine drugs during standard solid-phase extraction (SPE) approaches is described. An analytical method for promethazine (PMZ), chlorpromazine (CPZ) and their respective N-desmethyl and sulfoxide metabolites in biological samples (bone tissue extract and blood) by ultra performance liquid chromatography-photodiode array detection, using mixed-mode SPE for basic drugs was developed. When ethyl acetate:isopropanol:ammonium hydroxide (80:17:3) was used as the elution solvent during method development, extraneous peaks were observed that were absent in the negative controls. Analysis of extracts of PMZ and CPZ individually showed extraneous peaks, including peaks with retention time and UV spectra suggesting the formation of the sulfoxide metabolites, amongst others. Analytes were then extracted individually and analyzed by ultra performance liquid chromatography-quadrupole time-of-flight mass spectrometry. The results confirmed the oxidation of PMZ to its sulfoxide and N-oxide metabolites and oxidation of CPZ to its sulfoxide metabolite. Oxidation was also observed in analysis of whole blood, and thus was not specific to bone tissue extract. To determine if extraction with minimal oxidation was possible, extractions using SPE with a different elution solvent system (dichloromethane:isopropanol:ammonium hydroxide) and filtration/pass through extraction (FPTE) with and without evaporation were evaluated. The results demonstrated that the sample preparation method highly influenced the extent of oxidation. FPTE without an evaporation step was the only method that did not measurably induce analyte oxidation.

Chemically functionalized activated carbon with 8-hydroxyquinoline using aryldiazonium salts/diazotization route: Green chemistry synthesis for oxins-carbon chelators

The past few years witnessed the emergence of aryldiazonium salts as versatile coupling agents for the functionalization of carbon and other substrates. Although the approach has demonstrated extensive applications in many fields, its use for the synthesis of chelating resins has not been explored. In this work, the concept has been exploited to develop an ecofriendly synthetic method for carbon based chelators. Herein, the p-nitroanline aryldiazonium salt was generated (in situ) in presence of hypophosphorous acid and covalently grafted onto activated carbon (AC) to allow addition of 8-hydroxyquinoline (8-HQ) via diazo coupling. The successfulness of the functionalization was confirmed by DRIR, XPS, and TGA. The risen was packed into cartridges and used with standard solid phase extraction (SPE) apparatus for the extraction of trace metals; Cd(II), Ni(II), Mn(II), Zn(II) and Pb(II) from groundwater samples prior to their measurement by ICPMS. The resin exhibited more 50% enhancement in capacity exchange relative to the plain AC. Under the optimum conditions the sorption capacity of the sorbent was 0.393, 0.170, 0.345, 0.092, 0.314 mmol g−1 for Mn(II), Cd(II), Ni(II), Pb(II) and Zn(II) respectively. The sorbent showed efficient performance when applied for SPE of trace metals from groundwater certified reference materials BCR-609 and groundwater real samples from AlMadinah AlMumnawarah, Saudi Arabia.

A new strategy for accelerated extraction of target compounds using molecularly imprinted polymer particles embedded in a paper-based disk.

In this study, a general simple and inexpensive method is introduced for the preparation of a paper-based selective disk-type solid phase extraction (SPE) technique, appropriate for fast and high throughput monitoring of target compounds. An ion exchange molecularly imprinted polymer (MIP) was synthesized for the extraction and analysis of acesulfame, an anthropogenic water quality marker. Acesulfame imprinting was used as an example for demonstrating the benefits of a nanosized, swellable MIP extraction sorbents integrated in an on-site compatible concept for water quality monitoring. Compared with an 8mL standard SPE cartridge, the paper-based MIP disk (47mm ø) format allowed (1) high sample flow rates up to 30mL•min-1 without losing extraction efficiency (2) extracting sample volumes up to 500mL in much shorter times than with standard SPE, (3) the reuse of the disks (up to 3 times more than SPE cartridge) due to high robustness and an efficient post-cleaning, and (4) reducing the sampling time from 100minutes (using the standard SPE format) to about 2minutes with the MIP paper disk for 50mL water sample. Different parameters like cellulose fiber/polymer ratios, sample volume, sample flow-rate, washing, and elution conditions were evaluated and optimized. Using developed extraction technique with high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS-MS) analysis, a new protocol was established that provides detection and quantification limits of 0.015μg•L-1 and 0.05μg•L-1 , respectively. The developed paper disks were used in-field for the selective extraction of target compounds and transferred to the laboratory for further analysis.

Measuring Polycyclic Aromatic Hydrocarbons in Water using the Simultaneous Absorbance and Fluorescence Excitation-Emission Matrix Method: Advantages of Classical Least Squares Regression Over Parallel Factor Analysis

Many Polycyclic Aromatic Hydrocarbons (PAHs) are carcinogenic and hence of important environmental concern in drinking water sources. Most USEPA PAHs of concern exhibit high fluorescence quantum yields and sub mg/l to μg/l detection limits in neat solutions. However, drinking water sources commonly contain other natural compounds, including humic and fulvic acids and proteins, in carbon concentrations of several mg/l that exhibit significant interfering absorbance and fluorescence backgrounds in the PAH detection region. We investigated the use of the new simultaneous Absorbance and fluorescence Excitation-Emission Matrix (ABEEM) method to measure PAHs in raw water. The ABEEM method corrects fluorescence inner-filter effects to yield quantitative fluorescence spectral information to be largely independent of component concentrations. We compared Classical Least Squares Regression (CLS) and Parallel Factor Analysis (PARAFAC) in terms of identification and detection limits for the PAHs. The CLS library was calibrated with respect to concentration for the individual EPA PAHs dissolved in deionized organic-carbon free water. The same data set was used calibrate a model using the 3-way PARAFAC technique. Validation of the CLS and PARAFAC models was compared with PAHs added to natural raw water of varying organic carbon concentrations. Identification of individual PAHs and mixtures and detection limits were significantly better with CLS. The evaluation is consistent with the fundamental principles CLS vs. PARAFAC and primarily because CLS can be distinctly calibrated with the individual PAH component spectra. We conclude that the identification and detection limits of the ABEEM and CLS analysis can be significant enough for environmental contamination monitoring in drinking water sources; certainly, as a first screening method before the EPA standard solid-phase extraction and liquid or gas-chromatographic analysis methods.

Optimization for Peptide Sample Preparation for Urine Peptidomics.

Analysis of native or endogenous peptides in biofluids can provide valuable insight into disease mechanisms. Furthermore, the detected peptides may also have utility as potential biomarkers for noninvasive monitoring of human diseases. The noninvasive nature of urine collection and the abundance of peptides in the urine make analysis by high-throughput "peptidomics" methods an attractive approach for investigating the pathogenesis of renal disease. However, urine peptidomics methodologies can be problematic with regard to difficulties associated with sample preparation. The urine matrix can provide significant background interference in making the analytical measurements, in that it hampers both the identification of peptides and the depth of the peptidomics read when utilizing LC-MS-based peptidome analysis. We report on a novel adaptation of the standard solid-phase extraction (SPE) method to a modified SPE (mSPE) approach for improved peptide yield and analysis sensitivity with LC-MS-based peptidomics, in terms of time, cost, clogging of the LC-MS column, peptide yield, peptide quality, and number of peptides identified by each method. The mSPE method provides significantly improved efficiencies for the preparation of samples from urine. The mSPE method is found to be superior to the conventional, standard SPE method for urine peptide sample preparation when applying LC-MS peptidomics analysis, due to optimized sample cleanup that provides improved experimental inference from confidently identified peptides.

Carbonaceous nanomaterials immobilised mixed matrix membrane microextraction for the determination of polycyclic aromatic hydrocarbons in sewage pond water samples

In this study, the potential for carbonaceous nanomaterials to be used as adsorbents for the mixed matrix membrane (MMM) microextraction and preconcentration of organic pollutants was demonstrated. For this method, multiwall carbon nanotubes (MWCNT) and single layer graphene (SLG) nanoparticles were individually incorporated through dispersion in a cellulose triacetate (CTA) polymer matrix to form a MWCNT-MMM and SLG-MMM, respectively. The prepared membranes were evaluated for the extraction of selected polycyclic aromatic hydrocarbons (PAHs) present in sewage pond water samples. The extraction was performed by dipping a small piece of membrane (7 mm × 7 mm) in a stirred 7.5 mL sample solution to initiate the analyte adsorption. This step was followed by an analyte desorption into 60 μL of methanol prior to high performance liquid chromatography (HPLC) analysis. When the optimum SLG-MMM microextraction technique was applied to spiked sewage pond water samples, the detection limit of the method for the PAHs were in the range of 0.02–0.09 ng/mL, with relative standard deviations of between 1.4% and 7.8%. Enrichment factors of 54–100 were achieved with relative recoveries of 99%–101%. A comparison was also made between the proposed approach and standard solid phase extraction using polymeric bonded octadecyl (C18) cartridges.

Screening approach by ultra-high performance liquid chromatography-tandem mass spectrometry for the blood quantification of thirty-four toxic principles of plant origin. Application to forensic toxicology.

Plant poisonings have left their mark on history and still cause many deaths, whether intentional or accidental. The means to show toxicological evidence of such poisonings should be implemented with great care. This article presents a technique for measuring thirty-nine toxic principles of plant origin in the blood, covering a large amount of toxins from local or exotic plants: α-lobeline, α-solanine, aconitine, ajmaline, atropine, brucine, cephalomannine, colchicine, convallatoxin, cymarine, cytisine, digitoxin, digoxin, emetine, gelsemine, ibogaine, jervine, kavain, lanatoside C, lupanine, mitragynine, neriifolin, oleandrin, ouabain, paclitaxel, physostigmine, pilocarpine, podophyllotoxin, proscillaridin A, reserpine, retrorsine, ricinine, scopolamine, senecionine, sparteine, strophanthidin, strychnine, veratridine and yohimbine. Analysis was carried out using an original ultra-high performance liquid chromatography separation coupled with tandem mass spectrometry detection. Extraction was a standard solid phase extraction performed on Oasis(®) HLB cartridge. Thirty-four of the thirty-nine compounds were put through a validation procedure. The assay was linear in the calibration curve range from 0.5 or 5 μg/L to 1000 μg/L according to the compounds. The method is sensitive (LOD from 0.1 to 1.6 μg/L). The within-day precision of the assay was less than 22.5% at the LLOQ, and the between-day precision was less than 21.5% for 10 μg/L for all the compounds included. The assay accuracy was in the range of 87.4 to 119.8% for the LLOQ. The extraction recovery and matrix effect ranged from 30 to 106% and from -30 to 14%, respectively. It has proven useful and effective in several difficult forensic cases.

Optimization for peptide sample preparation for urine peptidomics

Analysis of native or endogenous peptides in biofluids can provide valuable insights into disease mechanisms. Furthermore, the detected peptides may also have utility as potential biomarkers for non-invasive monitoring of human diseases. The non-invasive nature of urine collection and the abundance of peptides in the urine makes analysis by high-throughput ‘peptidomics’ methods , an attractive approach for investigating the pathogenesis of renal disease. However, urine peptidomics methodologies can be problematic with regards to difficulties associated with sample preparation. The urine matrix can provide significant background interference in making the analytical measurements that it hampers both the identification of peptides and the depth of the peptidomics read when utilizing LC-MS based peptidome analysis. We report on a novel adaptation of the standard solid phase extraction (SPE) method to a modified SPE (mSPE) approach for improved peptide yield and analysis sensitivity with LC-MS based peptidomics in terms of time, cost, clogging of the LC-MS column, peptide yield, peptide quality, and number of peptides identified by each method. Expense and time requirements were comparable for both SPE and mSPE, but more interfering contaminants from the urine matrix were evident in the SPE preparations (e.g., clogging of the LC-MS columns, yellowish background coloration of prepared samples due to retained urobilin, lower peptide yields) when compared to the mSPE method. When we compared data from technical replicates of 4 runs, the mSPE method provided significantly improved efficiencies for the preparation of samples from urine (e.g., mSPE peptide identification 82% versus 18% with SPE; p = 8.92E-05). Additionally, peptide identifications, when applying the mSPE method, highlighted the biology of differential activation of urine peptidases during acute renal transplant rejection with distinct laddering of specific peptides, which was obscured for most proteins when utilizing the conventional SPE method. In conclusion, the mSPE method was found to be superior to the conventional, standard SPE method for urine peptide sample preparation when applying LC-MS peptidomics analysis due to the optimized sample clean up that provided improved experimental inference from the confidently identified peptides.

Increases in Levels of Epoxyeicosatrienoic and Dihydroxyeicosatrienoic Acids (EETs and DHETs) in Liver and Heart in Vivo by 2,3,7,8-Tetrachlorodibenzo-p-Dioxin (TCDD) and in Hepatic EET:DHET Ratios by Cotreatment with TCDD and the Soluble Epoxide Hydrolase Inhibitor AUDA

The environmental toxin and carcinogen 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD, dioxin) binds and activates the transcription factor aryl hydrocarbon receptor (AHR), inducing CYP1 family cytochrome P450 enzymes. CYP1A2 and its avian ortholog CYP1A5 are highly active arachidonic acid epoxygenases. Epoxygenases metabolize arachidonic acid to four regioisomeric epoxyeicosatrienoic acids (EETs) and selected monohydroxyeicosatetraenoic acids (HETEs). EETs can be further metabolized by epoxide hydrolases to dihydroxyeicosatrienoic acids (DHETs). As P450-arachidonic acid metabolites affect vasoregulation, responses to ischemia, inflammation, and metabolic disorders, identification of their production in vivo is needed to understand their contribution to biologic effects of TCDD and other AHR activators. Here we report use of an acetonitrile-based extraction procedure that markedly increased the yield of arachidonic acid products by lipidomic analysis over a standard solid-phase extraction protocol. We show that TCDD increased all four EETs (5,6-, 8,9-, 11,12-, and 14,15-), their corresponding DHETs, and 18- and 20-HETE in liver in vivo and increased 5,6-EET, the four DHETs, and 18-HETE in heart, in a chick embryo model. As the chick embryo heart lacks arachidonic acid-metabolizing activity, the latter findings suggest that arachidonic acid metabolites may travel from their site of production to a distal organ, i.e., heart. To determine if the TCDD-arachidonic acid-metabolite profile could be altered pharmacologically, chick embryos were treated with TCDD and the soluble epoxide hydrolase inhibitor 12-(3-adamantan-1-yl-ureido)-dodecanoic acid (AUDA). Cotreatment with AUDA increased hepatic EET-to-DHET ratios, indicating that the in vivo profile of P450-arachidonic acid metabolites can be modified for potential therapeutic intervention.

Pharmaceutical removal from wastewater by ferrate(VI) and preliminary effluent toxicity assessments by the zebrafish embryo model

Abstract Pharmaceuticals and their metabolites are inevitably emitted into the waters. The adverse environmental and human health effects of pharmaceutical residues in water could take place under a very low concentration range; from several μg L− 1 to ng L− 1. These are challenges to the global water industries as there is no efficient unit process to remove these pollutants. An efficient technology is thus sought to treat these pollutants in water and wastewater. A novel chemical, ferrate(VI) was assessed using a standard jar test procedure for the removal of pharmaceuticals. The analytical protocols of pharmaceuticals were standard solid phase extraction together with various instrumentation methods including LC-MS, HPLC–UV and UV/Vis spectroscopy. Removal of pharmaceuticals by ferrate(VI) was pH dependant and this was in coordinate to the chemical/physical properties of pharmaceuticals and ferrate(VI) speciation. Ferrate(VI) has shown higher capability in the degradation of ciprofloxacin than ibuprofen. Promising performance of ferrate(VI) in the treatment of real wastewater effluent was observed. Removal efficiency of ciprofloxacin was the highest among the target compounds (63%), followed by naproxen (43%). Moreover, both mortality of zebrafish embryo tests and microscopic images clearly demonstrated that raw wastewater effluents possessed toxicity to zebrafish but ferrate(VI) treated effluents had no adverse effects. This finding will encourage the implementation of ferrate(VI) in the treatment of wastewater containing pharmaceuticals.

Removal of Pharmaceutical Residues by Ferrate(VI)

BackgroundPharmaceuticals and their metabolites are inevitably emitted into the waters. The adverse environmental and human health effects of pharmaceutical residues in water could take place under a very low concentration range; from several µg/L to ng/L. These are challenges to the global water industries as there is no unit process specifically designed to remove these pollutants. An efficient technology is thus sought to treat these pollutants in water and waste water.Methodology/Major ResultsA novel chemical, ferrate, was assessed using a standard jar test procedure for the removal of pharmaceuticals. The analytical protocols of pharmaceuticals were standard solid phase extraction together with various instrumentation methods including LC-MS, HPLC-UV and UV/Vis spectroscopy. Ferrate can remove more than 80% of ciprofloxacin (CIP) at ferrate dose of 1 mg Fe/L and 30% of ibuprofen (IBU) at ferrate dose of 2 mg Fe/L. Removal of pharmaceuticals by ferrate was pH dependant and this was in coordinate to the chemical/physical properties of pharmaceuticals. Ferrate has shown higher capability in the degradation of CIP than IBU; this is because CIP has electron-rich organic moieties (EOM) which can be readily degraded by ferrate oxidation and IBU has electron-withdrawing groups which has slow reaction rate with ferrate. Promising performance of ferrate in the treatment of real waste water effluent at both pH 6 and 8 and dose range of 1–5 mg Fe/L was observed. Removal efficiency of ciprofloxacin was the highest among the target compounds (63%), followed by naproxen (43%). On the other hand, n-acetyl sulphamethoxazole was the hardest to be removed by ferrate (8% only).ConclusionsFerrate is a promising chemical to be used to treat pharmaceuticals in waste water. Adjusting operating conditions in terms of the properties of target pharmaceuticals can maximise the pharmaceutical removal efficiency.

Nicotiana glauca poisoning in ostriches (Struthio camelus)

Putative Nicotiana glauca (wild tobacco) poisoning was diagnosed in a flock of ostriches near Oudtshoorn, South Africa. Post mortem examinations (n = 7) were performed on ostriches (Struthio camelus) that had died. Suspicious leaf remnants (weighing 80-770 g), packed in a layer on top of other plant material, were carefully separated from the proventricular content and submitted for chemical determination of anabasine, the major toxic principle contained by this plant. A standard solid phase extraction method was used followed by an optimised liquid chromatography-mass spectrometry procedure. Anabasine was detected in the leaf remnants (114-177 microg/g dry weight) removed from the proventriculus of the ostriches that succumbed as well as in control N. glauca leaves (193 microg/g dry weight). The analytical methods used in this study revealed the presence of anabasine in the suspicious leaf remnants, indicating that the birds had been exposed to N. glauca and had died of this poisoning.