Publications by authors named "Patricia Weinert"

11 Publications

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New methods for assessing secondary performance attributes of sunscreens suitable for professional outdoor work.

J Occup Med Toxicol 2021 Jul 5;16(1):25. Epub 2021 Jul 5.

Institute for Health Research and Education, Department of Dermatology, Environmental Medicine and Health Theory, University of Osnabrück, Am Finkenhügel 7a, 49076, Osnabrück, Germany.

Background: Outdoor workers (OW) are highly exposed to solar ultraviolet radiation (UVR) and thus at increased risk for developing skin cancer. An essential part of an overall strategy to reduce workplace UVR-exposure to OW's skin is the usage of sunscreens. However, compliance with regular sunscreen usage seems to be low, as products are usually designed for recreational sun exposure and thus do not meet the requirements of physically active OW. To date, no standardized test procedures assess the suitability of sunscreens for professional use. The aim of this pilot study was to develop standardized methods of testing secondary performance attributes (PA) to represent real-life working conditions of outdoor work.

Methods: Ten sunscreen products, carefully selected after a detailed market survey of all relevant producers available on the German market, were evaluated regarding their suitability for professional outdoor work on 24 healthy volunteers in a newly designed test procedure. In addition to three standardized efficacy characteristics, i.e., sun protection factor, water-resistance, and UVA protection, we evaluated each PA involving parameters typically associated with outdoor workplaces.

Results: We developed standardized methods for objectifying the suitability of sunscreen products for professional outdoor work. The test procedures used are well feasible and appropriate for testing the PA because they represent practical working conditions in detail - although the degree of discriminability of single test methods varied. The claimed sun protection factor (SPF) of the products was confirmed; bio-stability of the SPF after physical activity was achieved in most cases. While most products hardly irritate the eyes and are quickly absorbed, the evaluation of the subjective skin feeling and non-slip grip is inconsistent.

Conclusions: In this pilot study, for the first time secondary PA are defined and examined. Although further objectification of the PA assessment as well as the establishment of minimum standards should be sought, the new methods could already complement the so far mandatory labels and in this way provide a significant impetus for the current scientific and political focus on the improvement of occupational health in highly UVR-exposed OW.
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http://dx.doi.org/10.1186/s12995-021-00314-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8256554PMC
July 2021

UV-Vis LED-assisted photo-Fenton process for mineralization of losartan and hydrochlorothiazide: optimization using desirability function.

Environ Sci Pollut Res Int 2021 May 9;28(19):24046-24056. Epub 2021 Jan 9.

Universidade Estadual de Ponta Grossa, Av. General Carlos Cavalcanti, 4748, Uvaranas, Ponta Grossa, PR, 84030-900, Brazil.

This study presents the results obtained for the optimization of the mineralization of losartan (LOS) and hydrochlorothiazide (HCTZ) using the photo-Fenton process with a UV-Vis LED. Experimental design optimization employing a Doehlert matrix and a global desirability function enabled simultaneous evaluation of multiple responses, with factor fitting providing the best conditions that maximized the mineralization efficiency: Fe at 10 mg L and HO at 100 mg L. High rates of mineralization of LOS and HCTZ were obtained, with dissolved organic carbon (DOC); removal of almost 75% after 90 min was observed for both pharmaceuticals. The kinetic model showed that the mineralization followed two regimes in the first minutes, with a fast progression followed by slower activity. The energy consumption calculated for mineralization of LOS and HCTZ at a concentration of 20 mg L using the UV-Vis LED-assisted photo-Fenton process, at 60 min, was 130 kWh m. The desirability function provides a useful tool for finding optimal experimental conditions for the treatment of effluents with different characteristics. The UV-Vis LED was shown to be a good light source in the photo-Fenton process.
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http://dx.doi.org/10.1007/s11356-020-12011-4DOI Listing
May 2021

Label-free impedimetric immunosensor based on arginine-functionalized gold nanoparticles for detection of DHEAS, a biomarker of pediatric adrenocortical carcinoma.

Biosens Bioelectron 2019 May 6;133:86-93. Epub 2019 Mar 6.

Department of Chemistry, Universidade Estadual de Ponta Grossa, Av. General Carlos Cavalcanti, 4748, 84030-900 Ponta Grossa, Paraná, Brazil. Electronic address:

Pediatric adrenocortical carcinoma (pACC) is a rare and aggressive malignancy of high occurrence in Southern Brazil. pACC is characterized by the usual overproduction of dehydroepiandrosterone sulfate (DHEAS), whose detection in serum or plasma can be effective to the early diagnosis of the disease. Therefore, the present paper reports, for the first time, the construction and application of a label-free impedimetric immunosensor to detect DHEAS, which was based on the modification of an oxidized glassy carbon electrode with arginine-functionalized gold nanoparticles (AuNPs-ARG) and anti-DHEA IgM antibodies (ox-GCE/AuNPs-ARG/IgM). AuNPs-ARG was synthesized by a green route, and characterized by UV-VIS spectroscopy, FTIR, TEM, DLS, and XRD. The construction of ox-GCE/AuNPs-ARG/IgM was optimized through factorial design and response surface methodology. Cyclic voltammetry and electrochemical impedance spectroscopy measurements were employed to characterize the optimized immunosensor. The DHEAS detection principle was based on the variation of charge transfer resistance (∆R) relative to the Fe(CN) electrochemical probe after immunoassays in the presence of the biomarker. A linear relationship between ∆R and DHEAS concentration was verified in the range from 10.0 to 110.0 µg dL, with a LOD of 7.4 µg dL. Besides the good sensitivity, the immunosensor displayed accuracy, stability, and specificity to detect DHEAS. The promising analytical performance of ox-GCE/AuNPs-ARG/IgM was confirmed by quantifying DHEAS in real patient plasma samples, with results that were comparable to the reference chemiluminescence assay. Our results suggest that the presented immunosensor can find clinical applications in the early diagnosis of pACC and to monitor DHEAS levels in other adrenal pathologies.
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http://dx.doi.org/10.1016/j.bios.2019.02.063DOI Listing
May 2019

In vitro bioaccessibility of Al, Cu, Cd, and Pb following simulated gastro-intestinal digestion and total content of these metals in different Brazilian brands of yerba mate tea.

Food Chem 2019 May 3;281:285-293. Epub 2019 Jan 3.

Departamento de Química, Universidade Estadual de Ponta Grossa (UEPG), Ponta Grossa, (UEPG), Ponta Grossa, PR 84030-900, Brazil. Electronic address:

Yerba mate tea contains various biochemically active substances. However, it can contain toxic metals. Thus, this work reports the total concentrations of Cd, Cu, Pb and Al in the commercial products, as well as the concentrations in infusions prepared. The bioaccessibility of these metals in these infusions was determined for the first time by in vitro digestion. For Al, its bioaccessibility was estimated in the presence of other ingredients used in tea consumption. In addition, the concentrations of phenolic compounds in infusions were also determined. All metals studied were detected in the samples ranging from 76 ng g (Cd) to 526 µg g (Al). In general, Cd and Cu were the most bioaccessible metals, while Al was found in a relatively inert form. The addition of sugar and honey in infusions decreased the Al bioaccessibility. The relationship between the phenolic and the leaching of Al for the beverages was observed.
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http://dx.doi.org/10.1016/j.foodchem.2018.12.102DOI Listing
May 2019

Development, validation and matrix effect of a QuEChERS method for the analysis of organochlorine pesticides in fish tissue.

J Environ Sci Health B 2018 Apr 26;53(4):246-254. Epub 2017 Dec 26.

a Department of Chemistry , Research Group on Environmental and Sanitary Analytical Chemistry (QAAS), Ponta Grossa State University (UEPG) , Ponta Grossa , Paraná , Brazil.

This study aims to develop and validate a method to determine OCPs in fish tissues, minimizing the consumption of sample and reagents, by using a modified QuEChERS along with ultrasound, d-SPE and gas chromatography with an electron capture detector (GC-ECD), refraining the pooling. Different factorial designs were employed to optimize the sample preparation phase. The validation method presented a recovery of around 77.3% and 110.8%, with RSD lower than 13% and the detection limits were between 0.24 and 2.88 μgkg, revealing good sensitiveness and accuracy. The method was satisfactorily applied to the analysis of tissues from different species of fish and OCPs residues were detected. The proposed method was shown effective to determine OCPs low concentrations in fish tissues, using small sample mass (0.5 g), making the sample analyses viable without the need for grouping (pool).
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http://dx.doi.org/10.1080/03601234.2017.1410414DOI Listing
April 2018

Jabuticaba (Myrciaria cauliflora) Seeds: Chemical Characterization and Extraction of Antioxidant and Antimicrobial Compounds.

J Food Sci 2016 Sep 4;81(9):C2206-17. Epub 2016 Aug 4.

Dept. of Chemistry, State Univ. of Ponta Grossa, Av. Carlos Cavalcanti, 4748, 84030-900, Ponta Grossa, PR, Brazil.

This study was aimed to assess the effect of time and temperature on the extraction of antioxidant compounds from jabuticaba seeds (Myrciaria cauliflora cv. Sabará), to optimize the solvent proportion (water, ethyl alcohol, and propanone), and to characterize the extract according to the chemical composition, antioxidant, and antimicrobial properties. Proximal composition, total phenolic content (TPC), antioxidant, and antimicrobial activities were analyzed. The optimized solvent ratio of 60% water and 40% propanone provided a mean TPC of 8.65 g GAE/100 g seeds and the antioxidant activity toward 2,2-diphenyl-1-picrylhydrazyl (DPPH) was 82.79% ± 0.50%. Time and temperature parameters did not influence the yield of TPC. The gross seed extract was partially purified and both exhibited a high antioxidant activity and antimicrobial potential toward Gram-positive and Gram-negative bacteria. The purified jabuticaba seed lyophilized extract contained a higher (P < 0.05) TPC, o-diphenols, flavonols, and antioxidant activity measured by the DPPH assay and total reducing capacity as compared to the gross lyophilized extract. Electrospray ionization coupled with tandem mass spectrometry (ESI-MS/MS) data showed the presence of ellagitannins and ellagic acid in the extracts, which are probably the responsible for the antimicrobial and antioxidant activities.
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http://dx.doi.org/10.1111/1750-3841.13405DOI Listing
September 2016

Sensitive flow-injection spectrophotometric analysis of bromopride.

Spectrochim Acta A Mol Biomol Spectrosc 2014 Dec 14;133:597-604. Epub 2014 Jun 14.

Instituto de Química, Universidade Estadual Paulista "Julio de Mesquita Filho", UNESP, R. Prof. Francisco Degni 55, P.O. Box 355, 14800-900 Araraquara, SP, Brazil. Electronic address:

A flow injection spectrophotometric procedure employing merging zones is proposed for direct bromopride determination in pharmaceutical formulations and biological fluids. The proposed method is based on the reaction between bromopride and p-dimethylaminocinnamaldehyde (p-DAC) in acid medium, in the presence of sodium dodecyl sulfate (SDS), resulting in formation of a violet product (λmax=565nm). Experimental design methodologies were used to optimize the experimental conditions. The Beer-Lambert law was obeyed in a bromopride concentration range of 3.63×10(-7) to 2.90×10(-5)molL(-1), with a correlation coefficient (r) of 0.9999. The limits of detection and quantification were 1.07×10(-7) and 3.57×10(-7)molL(-1), respectively. The proposed method was successfully applied to the determination of bromopride in pharmaceuticals and human urine, and recoveries of the drug from these media were in the ranges 99.6-101.2% and 98.6-102.1%, respectively. This new flow injection procedure does not require any sample pretreatment steps.
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http://dx.doi.org/10.1016/j.saa.2014.06.027DOI Listing
December 2014

An environmentally friendly reflectometric method for bumetanide determination in pharmaceuticals.

Anal Sci 2009 Jul;25(7):897-901

São Paulo State University-UNESP, Institute of Chemistry of Araraquara, Brazil.

This paper describes a green analytical procedure for the determination of bumetanide using diffuse reflectance spectroscopy. The proposed method is based on reflectance measurements of a violet compound produced from a spot test reaction between bumetanide and p-dimethylaminocinnamaldehyde (p-DAC) in an acid medium, using filter paper as a solid support. The best conditions for the reaction have been found by experimental design methodologies. All reflectance measurements were carried out at 525 nm, and the linear range was from 1.37 x 10(-4) to 1.37 x 10(-3) mol L(-1), with a correlation coefficient of 0.998. The detection limit was estimated to be 3.98 x 10(-5) mol L(-1). Five commercial medicines containing bumetanide were analyzed by the proposed method. No interferences were observed from the common excipients present in pharmaceutical formulations. The results were favorably compared with those obtained by the United States Pharmacopoeia procedure at 95% confidence level.
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http://dx.doi.org/10.2116/analsci.25.897DOI Listing
July 2009

An environmentally friendly reflectometric method for ranitidine determination in pharmaceuticals and human urine.

Spectrochim Acta A Mol Biomol Spectrosc 2009 Jan 3;71(5):1999-2004. Epub 2008 Aug 3.

Instituto de Química, São Paulo State University - UNESP, Araraquara, SP, Brazil.

This paper describes an environmentally friendly method for quantitative determination of ranitidine using diffuse reflectance spectroscopy. This method is based on the reflectance measurements of the colored product produced from the spot test reaction between ranitidine and p-dimethylaminocinnamaldehyde (p-DAC), in acid medium, using filter paper as solid support. Experimental design methodologies were used to optimize the optimal conditions. All reflectance measurements were carried out at 590 nm and the linear range was from 1.42x10(-3) to 3.42x10(-2) mol L(-1), with a correlation coefficient of 0.997. The limit of detection was estimated to be 1.09x10(-3) mol L(-1) (R.S.D.=1.9%). The proposed method was successfully applied to the determination of ranitidine in commercial brands of pharmaceuticals and no interferences were observed from the common excipients in formulations. The results obtained by the proposed method were favorably compared with those obtained by an official procedure at 95% confidence level. Additionally, the method was also applied to the determination of ranitidine in human urine showing excellent recoveries (99.6-100.3%).
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http://dx.doi.org/10.1016/j.saa.2008.07.036DOI Listing
January 2009

Flow-injection spectrophotometric determination of novalgin in pharmaceuticals using micellar medium.

Anal Sci 2007 Dec;23(12):1383-9

Instituto de Química-UNESP, P. O. Box 355, CEP 14801-970, Araraquara, SP, Brazil.

A sensitive flow-injection (FI) procedure with spectrophotometric detection in a micellar medium is proposed for the determination of novalgin. The method is based on the instantaneous formation of a red-orange product (lambda(max) = 510 nm) after the reaction between novalgin and p-dimethylaminocinnamaldehyde (p-DAC) in a dilute acid medium. The sensitivity of this reaction was increased by a factor of 5.6 in the presence of sodium dodecyl sulfate (SDS). Experimental design methodologies were used to optimize the chemical and FI variables. The calibration curve was linear in the range of 1.45 x 10(-6) to 2.90 x 10(-5) mol L(-1) with an excellent correlation coefficient (r = 0.9999). The detection limit was 1.31 x 10(-7) mol L(-1) (n = 20, RSD = 2.0%). No interferences were observed from the common excipients. The results obtained by the proposed method were favorably compared with those given by the iodometric reference method at 95% confidence level.
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http://dx.doi.org/10.2116/analsci.23.1383DOI Listing
December 2007

A simplified spectrophotometric method for routine analysis of saccharin in commercial noncaloric sweeteners.

J Agric Food Chem 2004 Dec;52(26):7788-92

Instituto de Química, UNESP, P.O. Box 355, 14801-970, Araraquara, SP, Brazil.

A simple, rapid, and sensitive spectrophotometric method for routine analysis of saccharin in commercial noncaloric sweeteners is proposed. This method is based on the reaction of saccharin with tetrachloro-p-benzoquinone (p-chloranil) accelerated by hydrogen peroxide and conducted in an ethanol:acetone (4:1) medium, producing a violet-red compound (lambda(max) = 550 nm). Beer's law is obeyed in a concentration range of 2.05 x 10(-4) to 3.00 x 10(-3) M with an excellent correlation coefficient (r = 0.9998). The detection limit was 1.55 x 10(-5) M, and the effect of interferences on the spectrophotometric measurements was evaluated. The proposed procedure was applied successfully to the determination of saccharin in noncaloric sweeteners. Recoveries were within 99.2-104.3% with standard deviations ranging from to 0.5-1.6%. Results of the proposed method compare very favorably with those given by the high-performance liquid chromatography method recommended by the Food and Drug Administration.
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http://dx.doi.org/10.1021/jf0402781DOI Listing
December 2004
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