•A multi-class multi-residue analytical method for veterinary drugs was developed.•A total of 132 veterinary drugs from almost 15 classes were investigated.•A magnetic hypercrosslinked ...polystyrene-based MSPE was developed.•The methodology was applied to the trace drug analysis of milk.
A quantitative multi-class multi-residue analytical method was developed for the determination of veterinary drugs in milk by high-performance liquid chromatography – tandem mass spectrometry (HPLC-MS/MS). A total of 132 veterinary drugs investigated belonged to almost 15 classes including sulfonamides, β-lactams, tetracyclines, quinolones, macrolides, nitrofurans, nitroimidazoles, phenicols, lincosamides, pleuromutilins, macrocyclic lactones, quinoxaline antibiotics, benzimidazoles, anthelmintics, coccidiostats and some others. A magnetic solid-phase extraction procedure was developed using magnetic hypercrosslinked polystyrene (HCP/Fe3O4) for the sample preparation prior to HPLC-MS/MS without deproteinization step. The results indicated recoveries of 85–107% for 14 sulfonamides, 85–120% for 13 β-lactams, 89–115% for 4 tetracyclines, 82–119% for 14 quinolones, 82–115% for 8 macrolides, 97–109% for 4 nitrofurans, 84–115% for 10 nitroimidazoles, 89–114% for 3 phenicols, 86–111% for 3 lincosamides, 97–102% for 2 pleuromutilins, 72–88% for 4 macrocyclic lactones, 87–104% for 4 quinoxaline antibiotics, 76–119% for 21 benzimidazoles, 79–115% for 12 anthelmintics, 81–118% for 12 coccidiostats and 75–119 % for 5 unclassified drugs, with relative standard deviations (RSDs) of less than 20%, and the LOQs ranged from 0.05 to 1 μg kg−1. This methodology was then applied to field-collected real milk samples and trace levels of some veterinary drugs were detected.
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•Emissions from the combustion of waste-based CWSP are no higher than at coal using.•Specialized additives to CWSP can reduce the emissions several times.•Wood wastes added to CWSP is ...environmentally and economically feasible.•Waste oils added to CWSP may boost the cost and energy efficiency.•Sawdust, charcoal, straw, glycerol, limestone are good admixtures for CWSP.
A promising solution to many problems that thermal power industry is facing today would be switching from conventional coal dust combustion to coal-water slurries containing petrochemicals (CWSP). Here, we perform an experimental study of the most hazardous anthropogenic emissions (sulfur and nitrogen oxides) from the combustion of high-potential CWSP. We identify the main benefits and potential drawbacks of using CWSP in thermal power industry. A set of components and additives to CWSP are explored that significantly affect the environmental and energy performance of fuels. The anthropogenic emissions from the combustion of CWSP made of widespread coal and oil processing wastes are no higher than those from coal dust combustion. Using specialized additives to CWSP, we can change the concentrations of NOx and SOx several times. The most appealing additives to CWSP are sawdust, straw, charcoal, limestone, and glycerol. They provide better environmental, economic, and energy performance and improve the rheological properties of CWSP. Waste oils and oil sludge added to CWSP may impair the environmental performance but boost the cost and energy efficiency. Using coal-water slurries containing petrochemicals as a fuel at thermal power plants is an environmentally friendly as well as cost- and energy-efficient way to recover industrial wastes.
Dispersive liquid–liquid microextraction (DLLME) is one of the most promising methods of the microextraction preconcentration of organic compounds. This method is eco-friendly, simple, and universal; ...in comparison with conventional extraction, the consumption of the reagents and solvents, the time of extraction, and the cost of analysis in this method are reduced. For a short time from the moment of the appearance of DLLME in 2006, analysts developed numerous versions, differing by the method of dispersion, the nature of the extractant and by combinations with other methods of sample preparation and methods of the subsequent determination of the preconcentrated substances. The popularity of the method among the analysts is attested in a great number of reviews summarized in this publication.
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•Formation of silver nanoparticles by flavonoid reduction was studied.•A role of different type flavonoids during AgNPs green synthesis was revealed.•Effects of a flavonoid nature and ...concentration, and other factors were studied.•A method for the spectrophotometric determination of flavonoids has been developed.•The method was applied for the analysis of biologically active food additives.
Formation of plasmonic silver nanoparticles by flavonoid reduction was studied. Effects of the nature and the concentration of a flavonoid and a stabilizer, composition of the solution and the interaction time were revealed. It was found that quercetin, dihydroquercetin, rutin and morin produced an intense surface plasmon resonance band of silver nanoparticles at 415nm which was linearly related to the concentration of a flavonoid, while chrysin, naringenin and naringin did not produce any remarkable changes. It was used for the spectrophotometric determination of the former four flavonoids with the detection limits of 0.03; 0.06; 0.09 and 0.1μgmL−1, respectively. The developed method was applied for the determination of flavonoids in biologically active food additives.
A rapid multi-residue LC-MS/MS method for the identification and determination of banned veterinary drugs in honey was developed. A total of 31 investigated veterinary drugs belonging to 4 classes ...including nitrofurans metabolites, nitroimidazoles, amphenicols, and quinolones were quantified by LC-MS/MS with ESI using one single injection. The sample preparation included treatment with 5-nitro-2-furaldehyde (5-NFA) in a thermostated ultrasonic bath (80 °C, 0.5М НСl, 20 min) to liberate matrix-bound residues of nitrofurans. Magnetic hypercrosslinked polystyrene (HCP/Fe3O4) was proposed for the solid-phase extraction and clean-up of target analytes prior to LC-MS/MS analysis. To evaluate and validate the performance of method, the criteria of the Decision (EC) no 2002/657 were applied. The LOQs of the examined analytes range from 0.3 to 1 μg kg-1, which indicates good sensitivity to quantify the target compounds in honey. The recoveries of veterinary drugs from 1 g of honey with 50 mg of the sorbent are 97-109% for nitrofuran metabolites, 84-115% for nitroimidazoles, 86-103% for amphenicols, and 97-118% for quinolones. The relative standard deviations of intra-day and inter-day precision analyses (RSD) are less than 16%. This methodology was applied to real honey samples and trace levels of some veterinary drugs were detected.
One of the possible ways for using silver nanoparticles (AgNPs) in spectrophotometry is their application for the determination of oxidizing agents, based on oxidative destruction of these ...nanoobjects. This process depends on the structure of AgNPs surface layer, which is essentially affected by the chosen stabilizer. To assess influence of the nanoparticle stabilizer and the nature of the analyte, possibilities of AgNPs covered with stabilizers of three types (citrate, polyvinylpyrrolidone, and polyhexamethylene guanidinium) for the spectrophotometric determination of hydrogen peroxide and differently substituted organic peroxides were studied. The approach is based on AgNPs oxidation leading to discoloration of the solution monitored spectrophotometrically. Different selectivity of the oxidation depending on the stabilizer was shown. Effects of various factors (time of interaction, pH, concentration of AgNPs) on the oxidation and analytical performance of the procedure were investigated. The method allows for the determination of hydrogen peroxide, peracetic acid, m-chloroperbenzoic acid, and t-butylhydroperoxide in the range of 0.3–1.5, 0.1–0.8, 1.0–7.5, and 1–7 μg mL−1 and with the limits of detection of 0.1, 0.04, 0.3, and 0.3 μg mL−1, respectively. The analysis can be performed using either spectrophotometry or naked-eye detection.
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•Oxidation of AgNPs covered with stabilizers of three types by peroxides were studied.•The type of an AgNPs stabilizer plays an important role in their oxidation.•Hydrogen peroxide and differently substituted organic peroxides are considered.•Best strategies for the determination of peroxides using AgNPs are proposed.
Single-drop microextraction (SDME) and hollow-fiber membrane microextraction (HFME) belong to methods of the liquid-phase microextraction preconcentration of organic compounds. These methods are ...characterized by the low consumption of organic solvents, high preconcentration factors, simplicity, low cost, ease of combination with various chromatographic methods; processes of preconcentration and sample injection are combined in a single device. Since the emergence of SDME (1996) and HFME (1999), a large number of versions have been developed that differ in the preconcentration technique, nature of the extractants used, and combinations with methods for the subsequent determination of the preconcentrated substances. The popularity of these methods among the analysts is evidenced by many reviews that we have summarized in this publication.
Gold nanorods (AuNRs) stabilized by cetyltrimethylammonium bromide (CTAB) were synthesized and an interaction of catecholamines (CAs) with silver ions in the presence of the obtained AuNRs was ...studied. The reaction results into formation of core-shell Au@Ag nanorods (Au@AgNRs) and leads to a hypsochromic shift of the long-wave surface plasmon resonance (SPR) band in the absorption spectrum of AuNRs. The influence of a CA structure, excess of CTAB, interaction time, pH, concentration of AuNRs, silver ions and CAs on this interaction was studied. Based on correlation of the NRs spectral characteristics with the concentration of CAs, a method for spectrophotometric determination of dobutamine, epinephrine, norepinephrine and dopamine with detection limits 27, 18, 16 and 13 μg L−1, respectively, has been developed. The method can be applied to the analysis of medicines.
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•Formation of core-shell Au@Ag nanorods under influence of catecholamines was systematically studied.•Influence of different parameters during the synthesis was evaluated.•Characterization of synthesized Au@Ag nanorods was performed.•A method for simple spectrophotometric determination of catecholamines was developed.
Possibilities of using analytical systems based on silver triangular nanoplates for the spectrophotometric determination of reductants are studied. It is found that the interaction of silver ...triangular nanoplates with L-ascorbic acid in the presence of silver(I) nitrate is accompanied by a bathochromic shift and an increase in the intensity of the surface plasmon resonance band of nanoparticles, which can be used as the basis for methods for determining reductants. The proposed interaction mechanism includes the reduction of Ag
+
ions to metallic silver under the action of an analyte and its deposition on the surface of nanoparticle seeds. The effects of pH, interaction time, and concentrations of reagents and foreign compounds on the value of the analytical signal are studied. The limit of detection for L-ascorbic acid under the selected conditions is 0.5 mg/L, the analytical range is 1.7–60 mg/L. The approach proposed in this paper was applied to the determination of L-ascorbic acid in leafy green tea and apple juice.
Effect of amines on formation of gold nanoparticles (AuNPs)/polymer nanocomposites has been observed and studied. Nanocomposites based on polyurethane foam and AuNPs were synthesized by interaction ...between the polymer modified with sodium borohydride and aqueous solution of tetrachloroauric acid. It has been shown that some amines cause a remarkable decrease of the surface plasmon resonance band of AuNPs in the nanocomposite material. Both aliphatic and aromatic amines as well as amines containing several amino groups were studied. A possible mechanism of the effect is discussed. It is probably based on stabilization of AuNPs with an amine that entails a decrease in the degree of their adsorption on PUF and appearance of the stabilized AuNPs in solution. The decrease of the nanocomposite surface plasmon resonance band is proportional to the concentration of amine in the solution. Based on this effect, a method for the determination of cetylamine, β-naphthylamine and neomycin in water and medical formulations using a monitor calibrator as a portable household tool is proposed. Under the selected conditions, the detection limits for amines were in the range of 0.7–1.5 μM, the determination ranges were approximately an order of magnitude. The observed color change of the nanocomposite samples also provides a good basis for semiquantitative determinations.
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•Au/polyurethane nanocomposites were prepared using the polymer modified with borohydride.•Amines cause a decrease of a surface plasmon resonance band of an Au nanocomposite.•Both aliphatic and aromatic amines/polyamines prevent formation of gold nanoparticles.•A method for the determination of amines using a household monitor calibrator was proposed.•The observed nanocomposite color change also suggests naked-eye detection.
