15 research outputs found

    Study of UV filters in cosmetic products and environmental samples

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    The main objective of this thesis is to develop analytical methods to determine a kind of cosmetic ingredients, the UV filters, in the cosmetics themselves, and in environmental matrices such as waters and beach sand. For that purpose, microextraction techniques and chromatographic analysis were employed. Seven studies are exposed. The first two methods presented were developed to analyse UV filters in cosmetics, and they are based on pressurized liquid extraction (PLE) followed by gas or liquid chromatography-tandem mass spectrometry. The following three methods are related to the analysis of the same compounds in water samples by ultrasound assisted emulsification microextraction (USAEME) and solid phase microextraction (SPME). Finally, different methods dealing with the analysis of UV filters in beach sand are presented

    Subcortical brain volume, regional cortical thickness, and cortical surface area across disorders: findings from the ENIGMA ADHD, ASD, and OCD Working Groups

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    Objective Attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorder (ASD), and obsessive-compulsive disorder (OCD) are common neurodevelopmental disorders that frequently co-occur. We aimed to directly compare all three disorders. The ENIGMA consortium is ideally positioned to investigate structural brain alterations across these disorders. Methods Structural T1-weighted whole-brain MRI of controls (n=5,827) and patients with ADHD (n=2,271), ASD (n=1,777), and OCD (n=2,323) from 151 cohorts worldwide were analyzed using standardized processing protocols. We examined subcortical volume, cortical thickness and surface area differences within a mega-analytical framework, pooling measures extracted from each cohort. Analyses were performed separately for children, adolescents, and adults using linear mixed-effects models adjusting for age, sex and site (and ICV for subcortical and surface area measures). Results We found no shared alterations among all three disorders, while shared alterations between any two disorders did not survive multiple comparisons correction. Children with ADHD compared to those with OCD had smaller hippocampal volumes, possibly influenced by IQ. Children and adolescents with ADHD also had smaller ICV than controls and those with OCD or ASD. Adults with ASD showed thicker frontal cortices compared to adult controls and other clinical groups. No OCD-specific alterations across different age-groups and surface area alterations among all disorders in childhood and adulthood were observed. Conclusion Our findings suggest robust but subtle alterations across different age-groups among ADHD, ASD, and OCD. ADHD-specific ICV and hippocampal alterations in children and adolescents, and ASD-specific cortical thickness alterations in the frontal cortex in adults support previous work emphasizing neurodevelopmental alterations in these disorders

    Miniaturized matrix solid-phase dispersion for the analysis of ultraviolet filters and other cosmetic ingredients in personal care products

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    A method based on micro-matrix solid-phase dispersion (μ-MSPD) followed by gas-chromatography tandem mass spectrometry (GC–MS/MS) was developed to analyze UV filters in personal care products. It is the first time that MSPD is employed to extract UV filters from cosmetics samples. This technique provides efficient and low-cost extractions, and allows performing extraction and clean-up in one step, which is one of their main advantages. The amount of sample employed was only 0.1 g and the extraction procedure was performed preparing the sample-sorbent column in a glass Pasteur pipette instead of the classic plastic columns in order to avoid plastizicer contamination. Factors affecting the process such as type of sorbent, and amount and type of elution solvent were studied by a factorial design. The method was validated and extended to other families of cosmetic ingredients such as fragrance allergens, preservatives, plasticizers and synthetic musks, including a total of 78 target analytes. Recovery studies in real sample at several concentration levels were also performed. Finally, the green extraction methodology was applied to the analysis of real cosmetic samples of different natureThis research was supported by the project UNST10-1E-491 (Ministry of Science and Innovation, Spain). The authors belong to the Galician Competitive Research Group GPC2017/04 and to the CRETUS Strategic Partnership (ED431 2018/01). All these programs are co-funded by FEDER (EU)S

    Miniaturized Matrix Solid-Phase Dispersion for the Analysis of Ultraviolet Filters and Other Cosmetic Ingredients in Personal Care Products

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    A method based on micro-matrix solid-phase dispersion (μ-MSPD) followed by gas-chromatography tandem mass spectrometry (GC–MS/MS) was developed to analyze UV filters in personal care products. It is the first time that MSPD is employed to extract UV filters from cosmetics samples. This technique provides efficient and low-cost extractions, and allows performing extraction and clean-up in one step, which is one of their main advantages. The amount of sample employed was only 0.1 g and the extraction procedure was performed preparing the sample-sorbent column in a glass Pasteur pipette instead of the classic plastic columns in order to avoid plastizicer contamination. Factors affecting the process such as type of sorbent, and amount and type of elution solvent were studied by a factorial design. The method was validated and extended to other families of cosmetic ingredients such as fragrance allergens, preservatives, plasticizers and synthetic musks, including a total of 78 target analytes. Recovery studies in real sample at several concentration levels were also performed. Finally, the green extraction methodology was applied to the analysis of real cosmetic samples of different nature

    Determination of multiclass personal care products in continental waters by solid-phase microextraction followed by gas chromatography-tandem mass spectrometry

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    A methodology based on solid-phase microextraction (SPME) followed by gas chromatography-tandem mass spectrometry (GC-MS/MS) was developed for the simultaneous analysis of different families of personal care products (PCPs) including fragrance allergens, synthetic musks, phthalates, antioxidants and UV filters in continental waters. The main parameters affecting SPME procedure were optimized by an ANOVA study. The final selected conditions comprised the use of 10 mL of sample with 20% (w/v) of sodium chloride (NaCl), polydimtehylsiloxane/divinylbenzene (PDMS/DVB) fiber and 20 min of extraction time at 100 degrees C in the head-space mode. Good linearity (R-2>0.9925), quantitative recoveries (>79%), and precision (RSD < 15%) were achieved for all compounds under the optimal conditions. Limits of quantification (LOQs) at the sub and low ng L-1 were obtained. The validated methodology was successfully applied to the analysis of river water samples from the North Portuguese coast allowing the determination of five different families of PCPs, including a total of 43 compounds in a single chromatographic run within 23 min. (C) 2019 Elsevier B.V. All rights reserved
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