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N-nitrosamines (NAs) are prevalent mutagenic impurities in various consumer products. Their discovery in valsartan-containing medicines in 2018 prompted global regulatory agencies to set guidelines on their presence and permissible levels in pharmaceuticals. In order to determine the NAs content in medicines, efficient and sensitive analytical methods have been developed based on mass spectrometry techniques. Direct analysis in real time-mass spectrometry (DART-MS) has emerged as a prominent ambient ionization technique for pharmaceutical analysis due to its high-throughput capability, simplicity, and minimal sample preparation requirements. Thus, in this study DART-MS was evaluated for the screening and quantification of NAs in medicines. DART-MS analyses were conducted in positive ion mode, for both direct tablet analysis and solution analysis. The analytical performance was evaluated regarding linearity, precision, accuracy, limits of detection, and quantification. The DART-MS proved to be suitable for the determination of NAs in medicines, whether through direct tablet analysis or solution analysis. The analytical performance demonstrated linearity in the range from 1.00 to 200.00 ng mL-1, limits of quantification about 1.00 ng mL-1, precision and accuracy lower than 15%, and no significant matrix effect for six drug-related NAs. In conclusion, the DART-MS technique demonstrated to be an alternative method to determine NAs in medicines, aligning with the principles of green chemistry.

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The coronavirus disease 2019 (COVID-19) pandemic has demonstrated that Wastewater Based Epidemiology is a fast and economical alternative for monitoring severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) at the community level in high-income countries. In the present study, wastewater from a city in the Peruvian Highlands, which lacks a wastewater treatment plant, was monitored for one year to assess the relationship between the concentration of SARS-CoV-2 and the reported cases of COVID-19 in the community. Additionally, we compared the relationship between rotavirus (RV), norovirus genogroup II (NoV GGII), and human adenovirus (HAdV) with the number of reported cases of acute gastroenteritis. Before commencing the analysis of the samples, the viral recovery efficacy of three processing methods was determined in spiked wastewater with SARS-CoV-2. This evaluation demonstrated the highest recovery rate with direct analysis (72.2 %), as compared to ultrafiltration (50.8 %) and skimmed milk flocculation (5.6 %). Wastewater monitoring revealed that 72 % (36/50) of the samples tested positive for SARS-CoV-2, with direct analysis yielding the highest detection frequency and quantification of SARS-CoV-2. Furthermore, a strong correlation was observed between the concentration of SARS-CoV-2 in wastewater and the reported cases of COVID-19, mainly when we shift the concentration of SARS-CoV-2 by two weeks, which allows us to anticipate the onset of the fourth and fifth waves of the pandemic in Peru up to two weeks in advance. All samples processed using the skimmed milk flocculation method tested positive and showed high concentrations of RV, NoV GGII, and HAdV. In fact, the highest RV concentrations were detected up to four weeks before outbreaks of acute gastroenteritis reported in children under four years of age. In conclusion, the results of this study suggest that periodic wastewater monitoring is an excellent epidemiological tool for surveillance and can anticipate outbreaks of infectious diseases, such as COVID-19, in low- and middle-income countries.

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The daily use of cosmetics may expose consumers to localized skin problems and systemic effects caused by absorption of chemical elements. The requirements for suitable quality control and maximum limits for toxic and potentially toxic elements in cosmetics have attracted the attention of the scientific community and of the official institutions around the world. Maximum limits for chemical elements in some cosmetics have been set, but there are disagreements between them. In the same context, many analytical methods have been proposed in the literature, but several challenges during the sample preparation and determination steps related to the high complexity of cosmetics' matrices composition still remain. It is extremely difficulty to establish suitable methods, free of interference, even using modern technology. In this review, methods for determining toxic and potentially toxic elements in cosmetics used for make-up on the lips and on the eye area, covering the period since 2000, are presented. Techniques enabling direct analysis and those requiring a sample preparation step prior to the analysis are also discussed. This review focused on cosmetics for make-up on the lips and on the eye area because the risks of percutaneous absorption and oral ingestion of toxic and potentially toxic elements is higher than in other body regions.

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Actinobacteria are one of the most promising producers of medically and industrially relevant secondary metabolites. However, screening of such compounds in actinobacteria growth demands simple, fast, and efficient extraction procedures that enable detection and precise quantification of biologically active compounds. In this regard, solid phase microextraction (SPME) emerges as an ideal extraction technique for screening of secondary metabolites in bacteria culture due to its non-exhaustive, minimally invasive, and non-destructive nature: its integrated sample preparation workflow; balanced coverage feature; metabolism quenching capabilities; and superior cleanup, as well as its versatility in configuration, which enables automation and high throughput applications. The current work provides a comparison of micro-scale and direct immersion SPME (DI-SPME) for screening of secondary metabolites, describes the optimization of the developed DI-SPME method, and introduces the developed technique for mapping of target secondary metabolites as well as its direct coupling to mass spectrometry for such applications. The optimized DI-SPME method provided higher amounts of extracted ions and intensity signals, yielding superior extraction and desorption efficiency as compared with micro-scale extraction. Studied compounds presented stability on the coating for 24 h at room temperature. The DI-SPME mapping approach revealed that lysolipin I and the lienomycin analog are distributed along the center and edges of the colony, respectively. Direct coupling of SPME to MS provided a similar ions profile as SPME-LC-MS while enabling a significant decrease in analysis time, demonstrating its suitability for such applications. DI-SPME is herein presented as an alternative to micro-scale extraction for screening of secondary metabolites in actinobacteria solid medium, as well as a feasible alternative to DESI-IMS for mapping of biologic radial distribution of secondary metabolites and cell life cycle studies. Lastly, the direct coupling of DI-SPME to MS is presented as a fast, powerful technique for high throughput analysis of secondary metabolites in this medium.

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Falsified, counterfeit and adulterated medicines are an endemic problem worldwide that results in both monetary and health-related losses. Developing fast and reliable methods that are able to present a timely result based on the drug's spectral profile is an effort that is sure to benefit those involved in the whole distribution chain. We propose herein a Laser Desorption/Ionization imaging-based method that provides simple and minimal sample preparation; this method is capable of providing specific markers that characterize adulterations, using as proof of concept one of the most adulterated drug products for oral use, sildenafil. Our approach is able to provide quality markers, which can be applied in the fast screening of any product within the same molecular class. This same strategy may be a useful alternative to provide accurate measurements with high specificity for unraveling contaminants and/or byproducts in virtually any given pharmaceutical product.

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The constant increase in seafood consumption worldwide has led to a parallel growth of the incidence of products obtained by aquaculture on the market, but also of the fraudulent commercialization of farmed products as wild-type ones. A careful characterization of the lipid component of seafood products based on chromatography-mass spectrometry techniques has been reported as a promising approach to reliably differentiate farmed from wild-type products. In this context, a fast method based on Direct Analysis in Real Time (DART) coupled to High Resolution Mass Spectrometry (HRMS) based on a single stage Orbitrap mass analyzer, integrated by Principal Component Analysis (PCA), was developed in the present study and applied to scout for spectral features useful to discriminate wild-type from farmed salmon of Salmo salar species. In particular, normalized intensities obtained for the 30 most intense signals (all referred to fatty acids, FA) detected in negative ion DART-HRMS spectra of the lipid extracts of salmon fillets [26 wild-type from Canada, 74 farmed from Canada (25), Norway (25) and Chile (24)] were considered as the variables for PCA. The scatterplot referred to the first two principal components showed a clear distinction between wild-type and farmed salmon, which gathered as a unique cluster, despite the remarkable differences in their geographical origin. In accordance with previous studies based on more complex and time-demanding analytical approaches, three saturated (14:0, 16:0 and 18:0) FA, along with unsaturated ones having 20 or 22 carbon atoms, were found as the main discriminating variables for wild-type salmons, whereas FA with compositions 18:1, 18:2, 18:3 and several oxidized forms arising from them were found to have a significantly higher incidence in farmed salmon. The method was further validated by Discriminant Analysis (DA) performed on the same dataset used for PCA integrated by data obtained from 6 commercial samples, putatively referred to farmed Norwegian salmon. Results showed that 100% of the latter were correctly classified as farmed type. Relative abundances of DART-HRMS signals related to specific FA appear then very promising for the differentiation of wild-type salmon from farmed ones, a very relevant issue in the context of consumers' protection from seafood frauds.

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The fractional factorial and Doehlert designs for optimization of a slurry sampling procedure to determine of nutrients in sugarcane juice by inductively coupled plasma optical emission spectrometry (ICP OES) were applied. External calibration curves were used for direct analysis of the slurry. This procedure allowed determination of Ca, Cu, Fe, K and Mg with limits of detection (LoD) obtained of 2.0, 0.04, 0.2, 1.0 and 1.5 mg L-1, respectively. The precision was expressed as relative standard deviation (%RSD), being better than 1.4% (n = 3). Accuracy was confirmed by comparison with sample digestion method. The results for analysis of fourteen sugarcane juices samples demonstrated that the nutrients Ca, Cu, Fe, K and Mg have average contents of 108, 0.506, 6.40, 470 and 114 mg L-1, respectively. The proposed analytical method is a good alternative for simultaneous determination of nutrients in sugarcane juice using introduction of slurries and detection by ICP OES.

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A fast and simple dilute-and-shoot procedure for determination of Al, As, Ba, Cd, Cu, Fe, Mg, Mn, Ni, Pb, Sc, Ti, V, Zn and Zr in deodorants by inductively coupled plasma optical emission spectrometry (ICP OES) was developed. Sample preparation was carried out by diluting 1 mL of deodorant sample in 1% (v v-1) HNO3. The accuracy of the analytical procedure was evaluated using addition and recovery experiments, and recoveries ranged from 80 to 119%. The limits of detection varied from 0.001 to 0.76 mg kg-1. Nine deodorants samples of different brands were analyzed. The maximum concentrations found (mg kg-1) were: Fe (1.0), Mn (0.1), Ti (1.02), V (0.33), Zn (255.2) and Zr (0.5); for Al and Mg, determined concentrations varied from 0.01 to 7.0% and from 0.005 to 1.44 mg kg-1, respectively, showing wide variation depending on the sample type. The developed procedure was adequate for determining these analytes in routine analysis presenting high sample throughput and demonstrated the feasibility of direct analysis measurements after simple dilution step.

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A method of direct analysis for quantification of 15 inorganic elements (P, S, Cl, K, Ca, Mn, Fe, Ni, Cu, Zn, Br, As, Rb, Sr and Pb) in beers by Total Reflection X-Ray Fluorescence (TXRF) was developed. The experimental conditions were optimized. Direct analysis was compared with the acid digestion procedure to evaluate the effect matrix and the results were satisfactory. The evaluation of the accuracy and precision was realized by analysis of two certified reference materials of natural and waste water. For the majority of the elements, good agreement was achieved between the certified value and the value measured in the CRM´s. Low detection limits were obtained and it was adequate to determine trace elements in beers and to quality control Pb and As, whose maximum limits are 200 and 100µgL-1, respectively. The relative standard deviation (RSD%) ranged from 2.4% to 10%. The method was applied to 30 beer samples collected in several regions of Brazil. The concentration ranges (mgL-1) for the studied analytes were: P: (37.40-140.85); S (10.32-50.73); Cl (82.74-281.7); K (183.8-418.5); Ca (9.82-96.0); Mn (0.06-1.42); Fe (0.07-1.57); Ni (< LLD-1.13); Cu (< LLD-0.32); Zn (0.02-1.98); As (< LLD-0.10); Br (0.01-2.04); Rb (< LLD-0.52); Sr (< LLD-0.41) and Pb (< LLD-0.18). Some beer samples showed As and Pb concentrations above the levels established by Brazilian legislation. The developed method is simple, fast, consumes low amounts of reagents and allows the determination of a large number of analytes simultaneously. TXRF proved to be attractive and useful for routine analysis.

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Milk is an important food in the human diet due to its physico-chemical composition; therefore, it is necessary to monitor contamination by toxic metals such as Pb. Milk sample slurries were prepared using Triton X-100 and nitric acid for direct analysis of Pb using graphite furnace atomic absorption spectrometry - GF AAS. After dilution of the slurries, 10.00µl were directly introduced into the pyrolytic graphite tube without use of a chemical modifier, which acts as an advantage considering this type of matrix. The limits of detection and quantification were 0.64 and 2.14µgl-1, respectively. The figures of merit studied showed that the proposed methodology without pretreatment of the raw milk sample and using external standard calibration is suitable. The methodology was applied in milk samples from the Guarapuava region, in Paraná State (Brazil) and Pb concentrations ranged from 2.12 to 37.36µgl-1.

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High-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS GF AAS) has been applied for the development of a method for the determination of total As in fish oil samples using direct analysis. The method does not use any sample pretreatment, besides dilution with 1-propanole, in order to decrease the oil viscosity. The stability and sensitivity of As were evaluated using ruthenium and iridium as permanent chemical modifiers and palladium added in solution over the sample. The best results were obtained with ruthenium as the permanent modifier and palladium in solution added to samples and standard solutions. Under these conditions, aqueous standard solutions could be used for calibration for the fish oil samples diluted with 1-propanole. The pyrolysis and atomization temperatures were 1400 °C and 2300 °C, respectively, and the limit of detection and characteristic mass were 30 pg and 43 pg, respectively. Accuracy and precision of the method have been evaluated using microwave-assisted acid digestion of the samples with subsequent determination by HR-CS GF AAS and ICP-MS; the results were in agreement (95% confidence level) with those of the proposed method.

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A method has been developed for the determination of lead in biomass, bio-oil, pyrolysis aqueous phase, and biomass ashes by high-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS GF AAS) and direct solid or liquid sample analysis. All measurements were performed without chemical modifier and calibration could be carried out using aqueous standard solutions. A pyrolysis temperature of 800°C and an atomization temperature of 2200°C were applied. The limits of detection and quantification were, respectively, 0.5 µg kg(-1) and 2 µg kg(-1) using the analytical line at 217.001 nm and 6 µg kg(-1) and 19 µg kg(-1) at 283.306 nm. The precision, expressed as relative standard deviation, was between 3% and 10%, which is suitable for direct analysis. The lead concentrations found for the solid samples varied between 0.28 and 1.4 mg kg(-1) for biomass and between 0.25 and 2.3 mg kg(-1) for ashes, these values were much higher than those found for bio-oil (2.2-16.8 µg kg(-1)) and pyrolysis aqueous phase (3.2-18.5 µg kg(-1)). After the determination of lead in the samples, it was possible to estimate the relative distribution of this element in the fractions of the pyrolysis products, and it was observed that most of the lead present in the biomass was eliminated to the environment during the pyrolysis process, with a significant portion retained in the ashes.

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Middle infrared spectroscopy and multivariate analysis have been applied for the development of methods to perform both quantitative and qualitative analysis of real drug samples seized by the Brazilian Police Federal (BPF). Currently, quantification of cocaine and determination of adulterants in seizures is performed using gas chromatography with flame ionization detection. However, this technique requires a relatively complex sample preparation, higher time of analysis, the destruction of sample and a high cost. In this context, this paper presents a simpler method to quantify cocaine and its major adulterants in seized materials. Out of 375 seizures, taken within a time frame of 2009-2013. A total of 1085 samples were analyzed of which 500 were selected for the calibration set and 585 for the validation set. Cocaine concentration in seized samples was determined by using middle infrared spectroscopy and partial least squares regression (PLSR), obtaining an average prediction error of 3.0% (w/w), precision of 2.0 and 11.8% (w/w) of minimum detectable cocaine concentration in a range varying from 24.2 to 99.9% (w/w). Results indicate that the developed method is able to discriminate between cocaine hydrochloride and free base samples, to quantify cocaine content as well as to estimate the concentration of main adulterants phenacetin, benzocaine, caffeine, lidocaine and aminopyrine.

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A measurement procedure for direct and simultaneous quantification of Na, K and Ca in biodiesel by flame atomic emission spectroscopy (FAES) was developed. A lab-made device was constructed by coupling a nebulizer/combustion system from a commercial photometer to a continuous emission detector in a spectral range of 255 to 862 nm. Instrumental optimizations were carried out evaluating the most important variables, such as gas flow rates and sample introduction temperature, indicating that a temperature of 50°C enhances the analytical signals and assures good precision. The direct analysis method was properly validated and presented limits of quantification of 0.09, 0.07 and 0.43 µg kg(-1) for Na, K and Ca, respectively. Accuracy of the proposed procedure was checked by comparing the results with those obtained by the standard procedure described in ABNT NBR 15556 and the standard addition method.

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Slurry sampling electrothermal atomic absorption spectrometry was used for direct determination of Cr, Pb and Cd in honey without sample pretreatment. The honey slurries were prepared in aqueous solution containing hydrogen peroxide and nitric acid. The slurries were directly introduced in the pyrolytic graphite tubes. Pd-Mg was used as a chemical modifier only for Cd determination. Analytical curves were performed with aqueous standards for Pb and Cr and with addition of fructose for Cd. The quantification limits for Cd, Pb and Cr were 2.0, 5.4 and 9.4ngg(-1), respectively. Acceptable precision of the methodology was obtained through repeatability and intermediate precision. In the accuracy study, recoveries were satisfactory (94-101%) for the three elements. The methodology was applied in honey from Paraná (Brazil). The concentrations of Pb, Cd and Cr ranged from 141 to 228ngg(-1), <2.0 to 8ngg(-1) and 83 to 94ngg(-1), respectively.

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Lipid pathways play important biological roles in mammalian embryology, directing early developmental pathways to differentiation. Phospholipids and triglycerides, among others, are the main composing lipids of zona pellucida in several embryo species. Lipid analysis in embryos by mass spectrometry usually requires sample preparation and/or matrix application. This novel approach using silica plate laser desorption/ionization mass spectrometry imaging (SP-LDI-MSI) allows direct single-cell imaging and embryo region discrimination with no matrix coating. Its application is herein described for two- and eight-cell embryos. Lipid biomarkers for blastomere and intact zona pellucida are reported and corroborated by both fragmentation reactions (MS/MS) and images. Results obtained in this work are understood to be of great use for further developments on in vitro bovine fertilization. Since much of the processes can be monitored by characteristic biomarkers, it is now possible to precisely identify cell division errors during early embryo stages, as well as evaluate pre-implantation conditions.

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La espectrometría de masas (MS) en condiciones ambientales es un campo nuevo de gran utilidad y de rápido crecimiento que provee espectros de masas de alta sensibilidad directamente a partir de superficies a presión atmosférica. Para ello se utilizan diversas técnicas de ionización, entre ellas: la ionización por desorción con electrospray (DESI: desorption electrospray ionization), el análisis directo en tiempo real (DART: direct analysis in real time), la ionización por desorción asistida por plasma (PADI: plasma assisted desorption ionization) y la ionización extractiva por electrospray (EESI: extractive electrospray ionization). Este trabajo se refiere en particular a los fundamentos y aplicaciones de DESI-MS con espectrometría de masas de imágenes. Entre otras aplicaciones, DESI es utilizado para el análisis directo de medicamentos y formulaciones farmacéuticas, muestras de fluidos biológicos, análisis forense, impresiones digitales, alimentos, cultivos de bacterias, identificación y distribución espacial de compuestos químicos en tejidos de origen animal y vegetal, y análisis de biomarcadores moleculares. Se destaca la posibilidad de combinación con cromatografía en capa delgada y con electroferogramas a fin de identificar mediante espectrometría de masas los compuestos presentes. Esta técnica no requiere preparación de las muestras y no implica el uso de matrices de ionización. Esto simplifica enormemente el procedimiento experimental y evita la redistribución de los analitos durante la deposición de la matriz. Se discute el análisis forense realizado con DESI-MS y DESI-MS/MS, respecto a: la detección de explosivos y agentes simulantes de guerra química en superficies sólidas cerca o a distancia del espectrómetro, análisis de telas o vestimenta en busca de explosivos y drogas, análisis de imágenes para la verificación de documentos, análisis sobre piel humana, análisis de residuos de disparos, análisis de gases tóxicos industriales y de agentes simulantes de guerra, de destilados de petróleo y de polímeros sintéticos. Se analizan las aplicaciones efectuadas en el campo de la lipidómica, proteómica y metabolómica. Por último, se brinda la información existente sobre el análisis cuantitativo realizado mediante DESI-MS.

Ambient mass spectrometry is a useful and rapidly growing new field that provides high sensitivity mass spectra directly from surfaces at atmospheric pressure. Various ionization techniques, including desorption electrospray ionization (DESI), direct analysis in real time (DART), plasma assisted desorption ionization (PADI) and extractive electrospray ionization (EESI) have been used. This paper refers particularly to the fundamentals and applications of DESI-MS based on imaging mass spectrometry. Among other applications, DESI is used for direct analysis of drugs and pharmaceutical formulations, samples of biological fluids, forensics, fingerprints, food, cultures of bacteria, identification and spatial distribution of chemicals in animal and plant tissues, and molecular biomarkers. It highlights the possibility of combination with thin layer chromatography and electropherograms to identify the compounds by mass spectrometry. This technique requires no sample preparation, and does not involve the use of matrix of ionization. It simplifies greatly the experimental procedure and avoids the redistribution of analytes during matrix deposition. The forensic analysis carried out by DESI-MS and DESI-MS/MS is discussed, including the detection of explosives and chemical warfare agents on solid surfaces near or at a distance from the mass spectrometer, analysis of fabric or clothing for explosives and drugs, image analysis for verification of documents, analysis of human skin, gunshot residue analysis, analysis of toxic gases and industrial warfare agent simulants, petroleum distillates and synthetic polymers. Aplications in the field of lipidomics, proteomics, and metabolomics are analyzed. Finally, current information on the quantitative analysis performed by DESI-MS is provided.

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