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A simple, accurate, precise, rapid and sensitive capillary zone electrophoresis (CZE) method was developed, optimized and validated for the simultaneous determination of strontium ranelate (antiosteoporetic drug) and aspartame (sweetener excipient) in pharmaceutical formulation for the treatment of postmenopausal osteoporosis. The final optimized conditions obtained were: borate buffer 50 mmol L-1 at pH 9.4 (BGE), applied potential of 30 kV, temperature set to 35 °C and hydrodynamic injection time of 10 s at a pressure of 50 mbar. The separation was carried out into a fused-silica capillary column (55 cm total length × 75 μm ID) and took less than 8 min. A diode array detector was used for the detection of the anion ranelate and aspartame at 235 and 198 nm, respectively. For both analytes, the method showed linear range from 1 to 40 μg mL-1, with satisfactory detectability (limits of detection of 0.3 and 0.2 μμg mL-1 for aspartame and ranelate, respectively). In addition, acceptable accuracy, good repeatability and intermediate precision (RSD < 2.6%) were obtained. The feasibility of the method was verified with recovery tests of analytes in the pharmaceutical sample. Recoveries varied from 85 ± 5% to 111 ± 2%, indicating the usefulness and effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

Ulva species have potential uses in several industrial sectors as they are rich in proteins, vitamins, fibers, and minerals. They also produce the essential amino acid tryptophan, which can act as an anxiolytic. With the increasing use of bioactive compounds obtained from algal species for commercial purposes, it will be necessary to evaluate the best methods for obtaining them, whether harvesting from natural beds or seaweed cultivation. Aquaculture has been indicated as an alternative method of acquiring algal biomass that avoids the harvesting and depredation of natural beds. To assess the feasibility of harvesting natural stocks of Ulva spp. (U. lactuca and U. flexuosa), algal biomass and relative species abundances were quantified at three sites in southeastern Brazil during 14 sampling periods. The results of those field biomass analyses allowed us to estimate their annual productions and compare them with projected productions of Ulva spp. under algaculture conditions. Tryptophan production by cultivated U. lactuca (as a high value-added product) was compared with the tryptophan concentrations of Ulva spp. from natural beds. No consistent patterns of total biomass production or relative abundances of the Ulva spp. were obtained during the sampling periods, making it impossible to accurately estimate sustainable biomass production for commercial uses. We diagnosed greater production sustainability in algaculture than in algal beds. The concentration of tryptophan produced by U. lactuca in algaculture was 60% higher than that from natural stocks. Tryptophan was quantified for the first time here in U. flexuosa. [ABSTRACT FROM AUTHOR]

Highlights • Five macrocyclic lactones were studied in cheese that is a very complex food matrix. • An analytical method was developed and validated, following international guidelines. • Excellent figures of merit were obtained with very low limits of quantification. • Twenty-one of the twenty-two cheeses studied contained macrocyclic lactones. • This is the first simultaneous evaluation of five macrocyclic lactones in cheeses. Abstract A highly sensitive analytical method was developed and validated, following international guidelines, for the determination of the residues of five macrocyclic lactones (MLs) (abamectin, doramectin, eprinomectin, ivermectin and moxidectin) in cheese. The extracts were concentrated by rotary-evaporation and derivatized; no clean-up was necessary. Despite matrix complexity, no significant matrix-effect was verified, and standards were prepared in solvents. Linear working ranges varied from 0.25 to 5.0 μg L−1. Excellent limits of quantification (0.58–0.87 μg kg−1), mean recoveries (91–103%), and repeatability and intermediate precision (<5.8%) were obtained. Twenty-two samples of bovine and non-bovine cheeses were analyzed. Twenty-one samples showed residues of at least one ML (between 0.59 and 15.3 μg kg−1), but moxidectin was never detected; a sample of mozzarella was free of MLs. To the best of our knowledge, this is the first method describing the simultaneous evaluation of these MLs in cheese using HPLC and fluorescence detection. [ABSTRACT FROM AUTHOR]

A method of high performance liquid chromatography with UV detection (HPLC-UV) was implemented and validated for formaldehyde determination in bovine milk. A formaldehyde derivatization reaction with 2,4-dinitrophenylhydrazine, at pH 4.0, enabled its detection in milk at 360 nm. The clean up treatment of milk samples by liquid-liquid extraction with low temperature partitioning (LLE-LTP) was thoroughly optimized. The linearity of the method was shown by analytical curves ranging from 10.0 to 400.0 μg L − 1 in aqueous solutions and milk samples that were characterized by R 2 > 0.99. The limit of quantification of 20.0 μg L − 1 demonstrated the high sensitivity of the method to determinate formaldehyde residues in milk. Extracts of milk samples fortified with formaldehyde at three concentration levels, led to a mean overall recovery of 102.2 ± 1.3% (n = 9), which satisfies the performance criteria established by the Codex Alimentarius for analytical methods suitable for determination of food residues. The accuracy was evaluated by comparison with a well-established procedure using the Student t -test. Comparable results were obtained at a 95% confidence level, demonstrating the usefulness and effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

Diabetic retinopathy (DR), the main cause of blindness among diabetic patients, affects both neuronal and vascular cells of the retina. Studies show that neuronal cell death begins after 4 weeks of diabetes and could be related with an increase in oxidative stress. System x c − is a glutamate/cystine exchanger, formed by a catalytic subunit called xCT and a regulatory subunit 4F2hc, whose activity is crucial to the synthesis of glutathione, which is a key antioxidant molecule for cells. Although some studies have shown that glutamate transport mediated by excitatory amino acid transporters (EAATs) in diabetic rats is downregulated, there are no studies investigating system x c − in this context. To evaluate whether system x c − is modified by early onset of diabetes, primary retinal cell culture exposed to high glucose and retinas of rats 3 weeks after streptozotocin injection were used. We observed that xCT subunit protein expression both in cultures and in vivo were diminished. Furthermore, system x c − activity and GSH levels were also decreased whereas oxidative stress was increased in retinas of diabetic animals. Therefore, this study raises the possibility that alterations in system x c − expression and activity could occur during early onset of diabetes. In that way, system x c − modifications could be related to increased ROS in diabetic retinopathy. [ABSTRACT FROM AUTHOR]

Formaldehyde has been illegally added to milk to reduce microbial activity and extend the shelf life of the product. In Brazil, the official method for formaldehyde detection in milk consists of a qualitative colorimetric analysis. This work aimed to develop a more sensitive method, based on Micellar Electrokinetic Chromatography with Diode Array Detection (MEKC-UV/DAD), to determine formaldehyde in bovine milk. Sample preparation consisted of formaldehyde derivatization with 2,4-dinitrophenylhydrazine followed by protein precipitation and extraction with acetonitrile. The method showed linearity in aqueous solutions and in milk in the range of 50.0–1000 μg/L (R2 > 0.99), LOQ of 50.0 μg/L, adequate precision (RSD <3.9%) and accuracy (average recovery: 94.2 ± 0.7%). Formaldehyde traces were found in two commercial milk samples. However, the concentration levels could not be considered adulteration because they were within the acceptable range of endogenous sources (0.1–0.3 mg/L). The usefulness and effectiveness of the developed method can contribute to increase food safety. • Formaldehyde is a dangerous adulterant added to milk due to its carcinogenic properties. • A new analytical method for milk quality assurance and control was developed. • First method reported to determine trace levels of formaldehyde in milk by MEKC-UV/DAD. • LOD was 160 times smaller than the official method recommended by Brazilian Surveillance Agency. [ABSTRACT FROM AUTHOR]

Abstract An analytical method was developed and validated for the simultaneous determination of alpha, beta and gamma-hydroxybutyric acids (AHB, BHB and GHB, respectively) in human hair. Hair samples (10 mg) were pulverized and submitted to extraction using methanol (1 mL) for 10 min. The extract was centrifuged, filtered, and evaporated to dryness at 40 °C under a gentle N 2 flow, dissolved in ethyl acetate (0.050 mL) and derivatized using 0.050 mL of BSTFA containing 1% TMCS, at °C for 40 min. The derivatives were determined by GC/MS. Aliquots of natural hair ("blank") samples after water extraction (3 steps) were pulverized, spiked with AHB, BHB, GHB or d 6 -GHB and used for method validation. Figures of merit showed the method's feasibility. The LOQ values were 1 ng mg−1 for BHB and AHB and 0.6 ng mg−1 for GHB, and mean recoveries were 54%, 69% and 75% for AHB, BHB and GHB respectively. Precision and bias were better than 15% and 20% respectively. Calibration curves (LOQ to 20 ng mg−1 for AHB and BHB and LOQ to 16 ng mg−1 for GHB) obtained in 5 days were pooled for statistical analysis, but the data were heteroscedastic, as demonstrated by the White test. Therefore, weighted linear regression and data transformations were applied and the best results were obtained using the Box-Cox transformation [c′ = (cλ-1)/λ] for GHB and log transformation for AHB and BHB. Authentic hair samples were collected from the posterior head vertex of 23 volunteers (16 females and 7 males). Four of them declared having type-2 diabetes (T2D). Only female volunteers reported hair treatments such as dyeing, flat ironing, straightening and/or bleaching. Dyeing appeared not to affect GHB levels in hair, but no data were found in the literature about other cosmetic treatments. GHB levels varied from < LOQ to 1.5 ng mg−1. BHB levels varied from < LOQ to 3.4 ng mg−1 and from < LOQ to 1.8 ng mg−1 in non-diabetic volunteers with or without family history of T2D, respectively. However, in diabetics, BHB levels varied from 3.4 to 5.2 ng mg−1. The levels of AHB varied from < LOQ to 1.2 ng mg−1 in non-diabetic individuals, and from 1.1 to 6.2 ng mg−1 in diabetics. Our results showed that AHB levels in hair have potential to as a biomarker for T2D, but this needs to be further studied with larger groups of volunteers. To our knowledge, this is the first published method for the determination of AHB and BHB in human hair. Graphical abstract fx1 Highlights • First method for simultaneous evaluation of isomeric hydroxybutyric acids in hair. • Very small sample aliquot (10 mg) was necessary for method application. • The figures of merit of the method showed its potential in Clinical and Forensic Sciences. • Determination of hair AHB showed potential as biomarker for type-2 diabetes. [ABSTRACT FROM AUTHOR]

The interest in charcoal for agricultural use (biochar) has sharply increased in recent years. However, biochar can contain groups of compounds such as polycyclic aromatic hydrocarbons (PAHs) that are considered persistent pollutants, and are formed concomitantly with biochar during its production by pyrolysis. Soil samples were collected in three experimental areas at different intervals (1, 3, 5 or 6 years) after the application of 16 Mg ha −1 of biochar. The total concentrations of PAHs; benzo[ a ]pyrene; and the estimated total cancer risk in biochar treated plots were larger than found in the control ones, but they decreased over time, equaling the control values after three years in the high C content soil (11.2 g C kg −1 soil), or after six years in the low C content soil (6.8 g C kg −1 soil). Nevertheless, the sum of PAH concentrations found in the biochar amended plots, in the range of 15.80–39.40 ng g −1 , were around two orders of magnitude below the limits of prevention established by Brazilian legislation (8100 ng g −1 ) and some European regulations for soils (3000 ng g −1 ) and also lower than the observed in previous studies about biochar amended soils. Our results indicate that, under the conditions evaluated, the application of biochar to soil in the studied proportion (16 Mg ha −1 , every six years) is safe concerning soil contamination by PAHs. [ABSTRACT FROM AUTHOR]

"Krokodil" is the street name for a homemade injectable drug that has been used as a cheap substitute for heroin. Codeine is the opioid starting material for krokodil synthesis, and desomorphine is claimed to be the main opioid of krokodil and the main component responsible for its addictive and psychoactive characteristics. However, due to its peculiar manufacture, using cheap raw materials, krokodil is composed of a large and complex mixture of different substances. In order to shed some light upon the chemical complexity of krokodil, its profiling was conducted by reverse phase high performance liquid chromatography coupled to a photodiode array detector (RP-HPLC-DAD) and by liquid chromatography coupled to high resolution tandem mass spectrometry (LC-ESI-IT-Orbitrap-MS). Besides desomorphine, codeine, and morphine, profiting from the high resolution mass spectrometry (HRMS) data, an endeavor to study the morphinans content in krokodil was set for the first time. Considering codeine as the only morphinan precursor and the possible chemical transformations that can occur during krokodil synthesis, the morphinan chemical space was designed, and 95 compounds were defined. By making use of the morphinan chemical space in krokodil, the exact masses featured by HRMS, and the morphinan mass fragmentations patterns, a targeted identification approach was designed and implemented.The proposed 95 morphinans were searched using the full scan chromatogram of krokodil, and findings were validated by mass fragmentation of the correspondent precursor ions (MS² spectra). Following this effort, a total of 54 morphinans were detected, highlighting the fact that these additional morphinans may contribute to the psychotropic effects of krokodil. [ABSTRACT FROM AUTHOR]

Objective 'Krokodil' is the street name for an impure homemade drug mixture used as a cheap substitute for heroin, containing desomorphine as the main opioid. Abscesses, gangrene, thrombophlebitis, limb ulceration and amputations, jaw osteonecrosis, skin discoloration, ulcers, skin infections, and bleeding are some of the typical reported signs in humans. This study aimed to understand the toxicity of krokodil using Wistar male rats as experimental model. Methods Animals were divided into seven groups and exposed subcutaneously to NaCl 0.9% (control), krokodil mixture free of psychotropic substances (blank krokodil), pharmaceutical grade desomorphine 1 mg/kg, and four different concentrations of krokodil (containing 0.125, 0.25, 0.5, and 1 mg/kg of desomorphine) synthesized accordingly to a 'domestic' protocol followed by people who inject krokodil (PWIK). Daily injections for five consecutive days were performed, and animals were sacrificed 24 hr after the last administration. Biochemical and histological analysis were carried out. Results It was shown that the continuous use of krokodil may cause injury at the injection area, with formation of necrotic zones. The biochemical results evidenced alterations on cardiac and renal biomarkers of toxicity, namely, creatine kinase, creatine kinase-MB, and uric acid. Significant alteration in levels of reduced and oxidized glutathione on kidney and heart suggested that oxidative stress may be involved in krokodil-mediated toxicity. Cardiac congestion was the most relevant finding of continuous krokodil administration. Conclusions These findings contribute notably to comprehension of the local and systemic toxicological impact of this complex drug mixture on major organs and will hopefully be useful for the development of appropriate treatment strategies towards the human toxicological effects of krokodil. [ABSTRACT FROM AUTHOR]

Reliable analytical results are necessary to ensure effective consumer protection and the use of certified reference material (CRM) is an important tool for quality assurance. The Brazilian Metrology Institute (Inmetro) studied the feasibility of the production of a candidate CRM of chloramphenicol (CAP) in milk. CAP is an antibiotic banned for treatment of food-producing animals. A minimum required performance limit (MRPL) for analytical methods of 0.3 μg kg −1 was set by the European Community for the detection of CAP residues in food matrices. Liquid chromatography with isotope dilution mass spectrometry (LC–IDMS) was employed for CAP determination and water content was measured by Karl Fischer coulometric titration. The feasibility study showed milk powder processed with both spray dryer and lyophilization lead to the best results, showing good degree of inhomogeneity for CAP residues (5.0%) and for water content (3.0%), therefore demonstrating that the production of this candidate CRM was feasible. [ABSTRACT FROM AUTHOR]

An analytical method was developed and validated for the simultaneous determination of four macrocyclic lactones (ML) (abamectin, doramectin, ivermectin and moxidectin) in butter, using liquid chromatography with fluorescence detection. The method employed heated liquid–liquid extraction and a mixture of acetonitrile, ethyl acetate and water, with preconcentration and derivatization, to produce stable fluorescent derivatives. The chromatographic run time was <12.5 min, with excellent separation. The method validation followed international guidelines and employed fortified butter samples. The figures of merit obtained, e.g. recovery (72.4–106.5%), repeatability (8.8%), within-laboratory reproducibility (15.7%) and limits of quantification (0.09–0.16 μg kg −1 ) were satisfactory for the desired application. The application of the method to real samples showed that ML residues were present in six of the ten samples evaluated. The method proved to be simple, easy and appropriate for simultaneous determination of ML residues in butter. To our knowledge, this is the first method described for the evaluation of ML in butter. [ABSTRACT FROM AUTHOR]

A method of high performance liquid chromatography with fluorescence detection (HPLC-Fluo), based on previous studies of the natural fluorescence emission of melamine (250/365 nm), was developed and validated for melamine determination as an adulterant of bovine UHT whole milk. The clean up treatment of milk samples by deproteinization was thoroughly optimized. No matrix effect was observed and a linear range from 0.05 to 10.0 μg mL −1 was obtained, with a value of R 2 equal to 0.9998. The limits of detection and quantification of melamine were 0.0081 and 0.027 μg mL −1 respectively, or 0.023 and 0.076 μg g −1 of milk, respectively, considering the sample dilution during extraction. Extracts of milk samples fortified with melamine at three concentration levels, two of which corresponded to the levels established by WHO for melamine in foods, led to an overall mean recovery of 95.4 ± 1.2% ( n = 9). This recovery value satisfies the performance criteria established by the Codex Alimentarius for analytical methods suitable for determination of food residues, demonstrating the usefulness and effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

Atmospheric particulate matter (total suspended particulate – TSP – and inhalable particles – PM10) and gas-phase samples were collected in three periods of seven to nine consecutive days in June and December 2011, and May 2012, in the central area of Niterói City, Rio de Janeiro State, Brazil. TSP (48.8–214 μg m −3 ) showed higher concentrations than PM10 (nd – 82.6 μg m −3 ). Sixteen polycyclic aromatic hydrocarbons (PAH) and thirty-one carbonyl compounds (CC) were evaluated. Concentrations of individual PAH ranged from

''Krokodil'' is the street name for the homemade injectable mixture that has been used as a cheap substitute for heroin. Its use begun in Russia and Ukraine and nowadays is being spread over several other countries. Desomorphine is the semi-synthetic opioid claimed to be the main component of krokodil and considered to be responsible for its psychoactive characteristics. The starting materials for desomorphine synthesis are codeine tablets, alkali solutions, organic solvent, acidified water, iodine and red phosphorus, all of which are easily available in retail outlets, such as supermarkets, drugstores, etc. The resulting product is a light brown liquid that is called krokodil. People who inject krokodil present a great variety of serious signs and symptoms, including thrombophlebitis, ulcerations, gangrene, and necrosis, quickly evolving to limb amputation and death. These effects are thought to result from the toxic components produced as byproducts during the homemade drug synthesis. In this work, we reviewed several aspects of krokodil use, including its epidemiology, pharmacology and the chemical properties of the main active ingredient (desomorphine). To enhance our understanding of the clinical and toxic effects and to support the implementation of harm reduction measures, we also describe the ''bathtub chemistry'' of krokodil and the content of the final solution. [ABSTRACT FROM AUTHOR]

Abstract: A relatively fast method was developed and applied to the determination of selected synthetic food dyes (Sunset Yellow, Tartrazine, Amaranth, Brilliant Blue and Red-40) in three different kinds of foodstuffs: solid juice powders, solid jelly powders and soft drinks. High performance liquid chromatography with UV-DAD detection was employed. The developed chromatographic method employed an ODS Zorbax column (250mm; 4.6mm; 5μm). Two different solvent systems were employed depending on the expected dyes in the studied samples. Sample preparation consisted of dissolving and filtering the samples and showed high throughput. Adequate detection and quantification limits together with high recoveries (better than 98.8%) were obtained. All studied samples showed dye levels in conformity with Brazilian legislation. Indeed some products showed poor quality and/or production controls due to the variability between lots. This fact was more critical for Tartrazine and Sunset Yellow in solid juice powders and there is concern that these substances can exceed legislated values. It was also observed that different producers use different dyes and/or composition in similar products. [Copyright &y& Elsevier]

Here we report the variation of diterpenes from three populations of the brown alga Dictyota mertensii. The populations were analyzed by 1H NMR and GC-MS techniques. Both chemical GC-MS and 1H NMR profiles of D. mertensii presented diterpenes as major constituents. In all populations, we detected the prenylated guaiane diterpenes, dictyoxide, pachydictyol A, isopachydictyol A, dictyol B and its acetate, and dictyol C. Although dictyol H has been described as a taxonomic marker, this diterpene was found in only two of the three studied populations. This result reinforces the need for studies of temporal and geographic variation for the establishment of the taxonomic limits of the species chemical patterns. It was also possible to observe mass spectra fragmentation and proton chemical shift in the NMR spectra characteristic from xeniane diterpenes, for the first time in this species, which led to the detection of dictyodial, suggesting that D. mertensii belongs to the chemotaxonomic group of species D. ciliolata, D. jamaicensis, and D. menstrualis , all of which are producers of diterpene from chemical groups I and III. Image 1 • The diterpenes from Brazilian populations of Dictyota mertensii were studied. • D. mertensii is a producer of diterpenes group I and III. • Dictyol H may not be detectable in some populations. • The chemical and its composition might be subjected to environmental conditions. [ABSTRACT FROM AUTHOR]