Evaluation of DLC, WC/C, and TiN Coatings on Martensitic Stainless Steel and Yttria-Stabilized Tetragonal Zirconia Polycrystal Substrates for Reusable Surgical Scalpels

DLC, WC/C, and TiN coated SF 100 martensitic stainless steel and Yttria-Stabilized Tetragonal Zirconia Polycrystal (Y-TZP) surgical scalpels were tested, characterized, and comparatively evaluated with regard to chemical leach, micromorphology, and mechanical properties in order to evaluate their suitability as reusable surgical scalpels. Vickers microhardness (HV), Scratch Hardness Number (), and sharpening by grinding and cutting capabilities of all the coated scalpels were deemed appropriate for reusable surgical scalpels. However, coated Y-TZP scalpels demonstrated higher Vickers microhardness than martensitic stainless steel scalpels coated with the same coatings, except DLC coating on Y-TZP substrate that presented less adhesion than the other coatings. Uncoated and coated martensitic stainless steel scalpels presented corrosion and chemical leach when soaked for a defined period of time in a simulant physiological saline solution, while uncoated and coated Y-TZP scalpels did not present these drawbacks. Therefore, DLC, WC/C, and TiN coated SF 100 martensitic stainless steel surgical scalpels are unsuitable as reusable surgical scalpels, limiting their application to disposable scalpels only, as the uncoated ones, despite their higher microhardness and expected longer cutting capability duration. Based on these experimental results, WC/C and TiN coated Y-TZP scalpels can be proposed as candidates for reusable surgical scalpel applications

Model study of the constituents of wall painting degradation patinas: The effect of the treatment with chelating agents on the solubility of the calcium salts

A model study on the application of chelating solutions on superficial calcium degradation patinas of wall paintings is presented. For this purpose the solubility of calcium sulfate, carbonate and oxalate in aqueous solutions of the Ca2 + chelators EDTA and citrate, was evaluated. Both the obtained solutions and their insoluble materials were analyzed by several analytical techniques. These studies revealed that the treatment of solid samples containing calcium sulfate and carbonate as the models of painting patinas resulted in higher solubilities of calcium sulfate and carbonate over that of oxalate. Moreover, our investigations confirmed the higher capacity of EDTA to chelate Ca2 + compared to that of citrate. All these results were interpreted and discussed on the basis of speciation models, solubility products of the salts and formation constants of the calcium complexes in solution. Finally, we report the characterization of a sodium calcium double citrate salt formed as an unexpected product in the treatment of the calcium sulfate with citrate. Overall our results suggest that the low solubility of calcium oxalate prevents its dissolution upon treatments with chelators, and that the capacity of citrate to dissolve the calcium salts is lower than that of EDTA irrespective of the duration of treatment

Exploiting the Reducing Properties of Lignin for the Development of an Effective Lignin@Cu2O Pesticide

Lignin is a natural polymer produced in huge amounts by the paper industry. Innovative applications of lignin, especially in agriculture, represent a valuable way to develop a more sustainable economy. Its antioxidant and antimicrobial properties, combined with its biodegradability, make it particularly attractive for the development of plant protection products. Copper is an element that has long been used as a pesticide in agriculture. Despite its recognized antimicrobial activity, the concerns derived from its negative environmental impact is forcing research to move toward the development of more effective and sustainable copper-based pesticides. Here a simple and sustainable way of synthesizing a new hybrid material composed of Cu2O nanocrystals embedded into lignin, named Lignin@Cu2O is presented. The formation of cuprite nanocrystals leaves the biopolymer intact, as evidenced by infrared spectroscopy, gel permeation chromatography, and Pyrolysis-GC analysis. The combined activity of lignin and cuprite make Lignin@Cu2O effective against Listeria monocytogenes and Rhizoctonia solani at low copper dosage, as evidenced by in vitro and in vivo tests conducted on tomato plants

Improved determination of chlorophenols in water by solid-phase microextraction followed by benzoylation and gas chromatography with electron capture detection

A rapid method for the determination of chlorophenols in drinking water by solid-phase microextraction and gas chromatography with electron capture detection was developed and validated. A fused silica fiber coated with a 65 pm thick stationary phase of poly (dimethylsiloxane)/divinylbenzene was used to extract chlorophenols after performing in situ derivatisation with pentafluorobenzoyl chloride in the polymeric coating. Validation was carried out in terms of limits of detection (LOD), limits of quantitation (LOQ), linearity and precision. In situ derivatisation and the choice of a fiber with more affinity towards the derivatised analytes gave LODs in the 0.005 - 0.8 mug L-1 range which are lower values than those reported in previous work using poly(dimethylsiloxane) or poly(acrylate) fibers. Linearity was statistically verified over one order of magnitude for each compound. The production of chlorophenols as disinfection by-products in the treatment of drinking water with chlorine was studied over a period of eight days: mono-, di- and trichlorophenols were detected and quantitated

Use of experimental design for optimisation of the cold plasma ICP-MS determination of lithium, aluminum and iron in soft drinks and alcoholic beverages

A sensitive method for the simultaneous determination of Li-7, Al-27 and Fe-56 by cold plasma ICP-MS was developed and validated. Experimental design was used to investigate the effects of torch position, torch power, lens 2 voltage, and coolant flow. Regression models and desirability functions were applied to find the experimental conditions providing the highest global sensitivity in a multi-elemental analysis. Validation was performed in terms of limits of detection (LOD), limits of quantitation (LOQ), linearity and precision. LODs were 1.4 and 159 ng L-1 for Li-7 and Fe-56, respectively; the highest LOD found being that for Al-27 (425 ng L-1). Linear ranges of 5 orders of magnitude for Li and 3 orders for Fe were statistically verified for each compound. Precision was evaluated by testing two concentration levels, and good results in terms of both intra-day repeatability and intermediate precision were obtained. RSD values lower than 4.8% at the lowest concentration level were calculated for intra-day repeatability. Commercially available soft drinks and alcoholic beverages contained in different packaging materials (TetraPack(R), polyethylene terephthalate (PET), commercial cans and glass) were analysed, and all the analytes were detected and quantitated

Low enthalpy Na-chloride waters from the Lunigiana and Garfagnana grabens, Northern Apennines, Italy. Tracing fluid connections and basement interactions via chemical and isotopic compositions

The Na-Cl waters from NW Tuscany (central Italy) record similar water isotopic and major chemical composi- tions, which demonstrate their meteoric origin and interactions with Upper Triassic evaporites and the metamor- phic units of the Paleozoic basement. Slight differences are found in the deep temperature-pressure conditions of the Lunigiana graben (39–42 °C/143–145 bar) and the Garfagnana graben (73–78 °C/250–256 bar). In particular, the thermal fluids outpouring from Garfagnana are probably related to a common deep reservoir or interconnect- ed fluids. Their differences are mainly evidenced by strontium isotopic ratio data (87Sr/86Sr), which combined with previously published sulfur isotope ratios (34S/32S) demonstrate the involvement of vein barites in water- rock interactions. Most likely, these minerals formed during Upper Oligocene-Miocene tectogenesis due to the mixing of fluids from the Verrucano Group and Upper Triassic units. The results of this hydrogeochemical study of the deep Na-Cl fluids could better clarify the distribution of the Verrucano Group within this area and the related discrepancies in the stratigraphic interpretations of the Palaeozoic-Mesozoic transition. Furthermore, the possible presence of an interconnected reservoir could be used to help interpret data produced by the local geochemical monitoring of seismic activity

Optimization of the solid phase microextraction procedure for the ultra-trace determination of organotin compounds by gas chromatography-inductively coupled plasma-mass spectrometry

A chemometric approach based on experimental design and desirability functions was used to develop and validate a SPME-GC-ICP-MS method for the determination of the organotin compounds dimethyltin, tributyltin and dibuthyltin. Three different SPME coatings were evaluated, obtaining the best results by using the divinylbenzene/carboxen/polydimethylsiloxane 2 cm 50/30 mm fibre. The optimal extraction conditions were found to be the following: T ¼ 30 1C, t ¼ 40 min and pH ¼ 4. Method validation was performed by determining the most relevant quality parameters such as detection limit, quantitation limit, repeatability and intermediate precision. LOD values in the 0.2–8 ng L_1 were obtained

Development and validation of an inductively coupled plasma mass spectrometry method with optimized microwave-assisted sample digestion for the determination of platinum at ultratrace levels in plasma and ultrafiltrate plasma

A highly sensitive inductively coupled plasma-mass spectrometry (ICP-MS) method with microwave-assisted sample digestion for the determination of total platinum in rat whole and ultrafiltrate plasma was developed and validated. A first step of this study concerned the optimization of the mineralization procedure, in order to obtain good extraction recovery (higher than 90%) and repeatability (less than 6%) and the absence of matrix effect. ICP-MS analysis was then performed using the “hot plasma/protective ion extraction” mode, achieving high sensitivity and very high signal/noise ratio. Iridium was added as internal standard. The method was then submitted to validation, performed according to the FDA Bioanalytical Validation Methods guidelines and to the Eurachem guide. Validation was carried out in terms of limit of detection (LOD), limit of quantitation (LOQ), linearity, precision, accuracy and stability. An instrumental LOQ of 1.9 ng L-1, corresponding to a concentration of 955 ng L-1 in matrix under the adopted conditions, was obtained, allowing the quantitative analysis of Pt ultratraces. Instrumental linearity was verified in the range 1.9-14000 ng L-1, corresponding to a concentration range from 955 ng L-1 to 6825 μg L-1 in matrix. Accuracy was evaluated by analyzing control samples for both matrices at different concentration levels; a good agreement (<15%) was obtained. Sample stability was tested by analyzing control samples maintained for 4 hours at room temperature or submitted to three freezing-thawing cycles. Finally, the developed method was applied to the analysis of plasma and ultrafiltrate plasma of rats treated with oxaliplatin-base drug, thus demonstrating its reliability in pharmacokinetic studies