Determination of Multiclass Antibiotics in Fish Muscle Using a QuEChERS-UHPLC-MS/MS Method.

The surging global demand for fish has increased aquaculture practices, where antibiotics have become indispensable to prevent diseases. However, the passive incorporation of these compounds into the diet may have adverse effects on human health. In this work, the QuEChERS method combined with ultra-high-performance liquid chromatography tandem mass spectrometry was applied for the determination of 10 multiclass antibiotics (5 quinolones, 2 sulfonamides, 2 diaminopyrimidines, and 1 macrolide) in muscle tissue of farmed fish (European sea bass and gilt-head sea bream). The applied method demonstrated acceptable recovery values, mostly between 70 and 120%, with limits of quantification of the method meeting the established EU maximum residue limits. The analysis of twenty fish samples in duplicate revealed that most antibiotics were not present, with the only exception of oxolinic acid and tilmicosin in European sea bass, which were below the limit of quantification of the method.

Natural clay as a sorbent to remove pharmaceutical micropollutants from wastewater.

Worldwide, the aquatic environment is contaminated by micro-pollutants, such as ingredients of personal care products, pesticides and pharmaceuticals. This contamination is one of the major environmental issues of global concern. Adsorption is one of approach, which has been most extensively discussed within recent years for the reduction of the input of micro-pollutants into the environment. In the present study, the natural clay classified as Na-montmorillonite, was characterized and tested for its potential to remove four model compounds representing different polarity and ionizability: i) diatrizoic acid (DAT), ii) iopamidol (IOP), iii) metformin (MTF), and iv) carbamazepine (CBZ). The adsorption efficiency of clay was evaluated by initial compound concentration, effect of pH, contact time and temperature. The results indicated that clay was able to remove the pharmaceuticals from aqueous medium with an efficiency of 70% for CBZ and MTF. In contrast, clay showed a lower removal of 30% for DAT and no removal for IOP. The results indicate that clay could rapidly and efficiently reduce the concentration of CBZ and MTF, which could provide a solution to remove some substances, without undesirable by-product generation. However, this study clearly demonstrated that removal rates strongly depend on the compound. Albeit chemical structure may play a role for the different degree of removal, this study could not completely explain the sorption mechanism between sorbent-sorbate interactions.

Clay-Na as a sorbent for the extraction of anti-inflammatory compounds in water samples.

In this work, clay-Na particles are used as the adsorbent for the solid-phase extraction of acidic compounds. The novel sorbent under study is based on high-specific surface area, cation-exchange capacity designed specifically to offer ion-exchange properties with the goal being to selectively extract a group of acidic compounds. The effects of the extraction parameters including extraction elution solvent, sample volume and pH. In optimum conditions, the repeatability for one fiber (n = 3), expressed as % relative standard deviation, was between 0.3 and 4.3% for the acid compounds. The detection limits for the studied acidic compounds were between 0.1-0.6 µg/L. The developed method offers the advantages of being simple to use and having a low cost of equipment.

Solid-phase extraction of drugs with cuttlefish bone powder as a sorbent.

We investigated cuttlefish bone powder for the solid-phase extraction of naproxen, ibuprofen, and carbamazepine. The basic principles controlling the extraction are presented to aid in the choice of the nature and quantity of the extracting phase according to the sample matrix and the solute properties, based on the mechanisms of phase retention. Their retention mechanism is based on hydrogen bonding and electrostatic interactions. The results show a significant recovery rate for the three drugs, selectivity, and low cost. The method has successfully reduced the amount of tested pharmaceuticals with recoveries >87% at pH 4.

Removal of two anionic reactive textile dyes by adsorption into MgAl-layered double hydroxide in aqueous solutions.

Textile dyes pose a significant challenge for water pollution due to the poor degradability of their complex aromatic structures (e.g., RR-120 and RBB-150). In order to minimize the harmful effects of RR-120 and RBB-150, the capacity of MgAl-layered double hydroxide for removing of these contaminants was studied herein. Batch adsorption experiments were conducted to investigate the effect of various operating parameters, such as solution pH, contact time, dye concentration, and temperature in order to provide optimal conditions for removal. Structural and morphological analyses were used to highlight the assembly and/or interaction LDH-dye. The state of equilibrium of RR-120 and RBB-150 adsorption was pH- and temperature-dependent and followed the pseudo-second-order rate model. Also, the equilibrium adsorption data of both dyes were found to adopt the Langmuir type isotherm model, which assumes a monolayer arrangement in LDH-dye. Furthermore, the effects of four major coexisting and competing mono- and divalent interlayer anions, such as NO3-, Cl-, CO32-, and SO42-, on the uptakes of RR-120 and RBB-150 were studied and the results showed that NO3- anions had insignificant effect on the uptakes of RR-120 and RBB-150 by MgAl. An equivalent study on the presence of both dyes in competitive trial adsorption/desorption from binary aqueous solution was investigated. And finally, the reuse operation of recovered material after dye adsorption was tested in up to 5 cycles of recyclability.

Extraction of clarithromycin and atenolol by cuttlefish bone powder.

Pharmaceutical products including analgesics, antibiotics, and antiepileptics are often present in wastewater treatment effluents, lakes, and rivers and have been found in waterways of many countries. The adsorption of two common pharmaceuticals present in surface waters, clarithromycin (CLR) and atenolol (ATN), onto cuttlefish bone powder treated with HCl has been investigated. Adsorption experiments were carried out at different pH conditions and the experimental equilibrium data were fitted to the Langmuir and Freundlich. For the same experimental conditions (pH = 7), the estimated adsorption capacities are from 34.5 mg g-1 for CLR and 39.5 mg g-1 for ATN. The influence of adsorption pH was established for each compound. The negative values of ΔG at different temperatures for all samples indicate the spontaneous nature of the sorption process.

Nanoscale zero-valent iron functionalized Posidonia oceanica marine biomass for heavy metal removal from water.

Because of the excellent reducing capacity of nanoscale zero-valent iron (NZVI), it can be used as alternative materials for the removal of a variety of reducible water contaminants including toxic metals. The current paper reports the research results obtained for self-prepared biosorbent, Posidonia oceanica biomass, activated in alkaline medium and functionalized with NZVI particles. The structural characteristics, surface morphology, and binding properties of the resulting nanobiosorbent are presented. Batch comparative adsorption trials including adsorption kinetics and isothermals onto raw Posidonia, Posidonia-OH and Posidonia-OH-NZVI were investigated on three heavy metal ions: Cd(II), Pb(II), and Cu(II). The nanobiosorbent showed better properties, such as high reactivity and high uptake rate through the sorption process. The toxic metal removal has been monitored in terms of pseudo-first- and pseudo-second-order kinetics, and both Langmuir- and Freundlich-type isotherm models have been used to describe the sorption mechanism. The experimental data of all studied systems showed that the uptake kinetics follow the pseudo-second-order kinetic model and the equilibrium uptake can adopt the Langmuir-type isotherm model which assumes a monolayer coverage as the adsorption saturates and no further adsorption occurs. The thermodynamic results confirm that all sorption processes were feasible, spontaneous and thermodynamically favorable. Zeta potential data displayed that Cd(II), Pb(II), and Cu(II) tend to be reduced after exposure on the Posidonia-OH-NZVI surface. Furthermore, sorption competitions of the metals from binary and ternary systems were carried out onto Posidonia-OH-NZVI in order to gain further insight into the sorption efficiency of this material. Therefore, as a result, the proposed new nanobiosorbent could offer potential benefits in remediation of heavy metal-contaminated water as a green and environmentally friendly bionanocomposite.

Simultaneous detection of antibiotics and other drug residues in the dissolved and particulate phases of water by an off-line SPE combined with on-line SPE-LC-MS/MS: Method development and application.

Due to their widespread use in human and animal healthcare, antibiotics and other drug residues are ubiquitous in the aquatic environment. Given their potential impacts on ecosystem functioning and public health, the quantification of environmental drug residues has become a necessity. Various analysis techniques have been found to be suitable for reliable detection of such compounds. However, quantification can be difficult because these compounds are present at trace or ultra-trace levels. Consequently, the accuracy of environmental analyses depends on both the efficiency and the robustness of the extraction and quantification method. In this work, an off-line solid-phase extraction (SPE) combined with on-line SPE-LC-MS/MS was applied to the simultaneous extraction and quantification of 26 pharmaceutical products, including 18 antibiotics, dissolved in a water phase. Optimal conditions were determined and then applied to assess the contamination level of the targeted drug residues in water collected from four sites in Northern France: a river, the input and output of an aerated lagoon, and a wastewater treatment plant. Drug residues associated with suspended solid matter (SSM) were also quantified in this work using pressurized liquid extraction (PLE) combined with an on-line SPE-LC-MS/MS system in order to complete an assessment of the degree of total background pollution.

[Pediatric celiac disease in the region of Sousse: epidemiological and evolutive study of 80 cases]. / Maladie coeliaque de l'enfant dans la région de Sousse: étude épidémiologique et évolutive de 80 cas.

AIM: Analyze epidemiological and evolutive profile of paediatric celiac disease in the region of Sousse. METHODS: We studied retrospectively 80 cases enrolled in the paediatrics' department of Sousse between 1993 and 2003. RESULTS: There were 44 girls and 36 boys (sex-ratio=0.81). The middle age of gluten introduction was 9 months, with extremes going from 1 to 24 months. Free interval between the introduction of gluten and the beginning of the symptoms was meaningfully more elevated in patients who received gluten after the age of 6 months (p=0.036). At the time of the diagnosis, the middle age of our patients was six years with extremes going from nine months to 17 years. The classic form of celiac disease with chronic diarrhoea has been observed in 85% of the cases. The morbid associations with celiac disease were dominated by the diabetes type 1 noted in 5% of the cases. Antigliadin antibodies, practiced in first intension, were positive in 98.6%. At histology, villous atrophy was sub-total to total in 96.25% of the cases and partial in 3.75% of the cases. Follow-up was on average at 18 months. Adhesion to the gluten-free diet (GFD) was judged satisfactory in 81.45% of the cases on average. Catch up growth, although remarkable, was not very satisfactory. Indeed, several patients adhering little or not to the GFD kept, at one year of evolution, a ponderal and stature delay superior to 2SD.