Profa. Dra. Helena M. C. Ferraz

Silva, Luiz Fernando da

doi:10.1590/s0100-40422007000700051

Cited by 9 publications

(12 citation statements)

References 11 publications

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“…The pesticides whith lower polarity, chlorpyrifos (log K ow = 4.7) and pendimentalina (log K ow = 5.2), showed a higher amount of mass retained due to higher affinity for the PDMS fiber (nonpolar). Similar results were found by Beltran et al 33 and Silva et al 34 for extraction of organophosphorus pesticides using PDMS and PA fibers. …”

supporting

confidence: 89%

Multiresidue methods for determination of pesticides using SPME and SPE followed by GC-NPD system: a comparative study

Milhome

Sousa

Keukeleire

et al. 2011

J. Braz. Chem. Soc.

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Neste estudo, métodos multirresíduos usando extração em fase sólida (SPE) e microextração em fase sólida (SPME) são comparados na determinação de pesticidas em amostras aquosas. Parâmetros como tipo de fibras e espessura, solvente de eluição, volume da amostra, tempo de equilíbrio, coeficiente de partição e solubilidade foram investigados. Resultados satisfatórios foram obtidos para a análise de pesticidas usando cartuchos C18 e acetato de etila como eluente, com taxas de recuperação entre 75-107%. As melhores condições para SPME foram com uma fibra PDMS 100 µm de espessura, volume de amostra de 40 mL, e tempo de equilíbrio de 45 min. O método SPME é o mais adequado para a análise de pesticidas em água, devido à sua rapidez e simplicidade e ao não uso de solventes. Os limites de detecção e quantificação são inferiores aos limites de concentração máximos estabelecidos pelas autoridades brasileiras, sendo portanto aceitável.In this study, multiresidue method using solid phase extraction (SPE) and solid phase microextraction (SPME) are compared in the determination of pesticides in aqueous samples. Parameters such as fiber type and thickness, elution solvent, sample volume, equilibration time, partition coefficient and solubility were investigated. Satisfactory results were obtained for the analysis of pesticides using C18 cartridges and ethyl acetate as eluent, whith recovery rates between 75-107%. The best conditions for SPME fiber were PDMS with a 100 mm thick, sample volume of 40 mL, and reaction time was 45 min. SPME method is most suitable for the analysis of pesticides in water, due to its speed and simplicity and solvent-free. The limits of detection and quantification are below the maximum concentration limits established by Brazilian authorities and therefore acceptable.Keywords: pesticides, SPME, water analysis, microextraction, partition coefficient IntroductionThe protection of water quality is a real concern of government agencies that control public health. The worldwide intensive use of pesticides plays a key role in environmental contamination, especially in water resources. In the last years, Brazil has been considered the largest consumer of pesticides in the world. 1 Only in 2009, around 1 million ton of pesticides were sold in the country,mainly applied in soybean, corn, sugarcane and cotton cultures. 1 According to ANDEF, there were about 475 active ingredients and 1278 products registered. 2 Pesticides that remain in the environment or reach the aquatic systems pose risks to animal species by their toxicity and ability to bio-accumulate along the food chain. 3 The European Community has set the value of 0.1 mg L -1 for any individual pesticide and 0.5 mg L -1 for the total pesticide residues of pesticides. In Brazil, the maximum concentrations of pesticides in water are regulated by the Administrative Rule No. 518/2004 (drinking water) of the Milhome et al. 2049 Vol. 22, No. 11, 2011 Ministry of Health, by The National Environment Council (CONAMA) Resolution No. 357/2005(classification o...

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supporting

confidence: 89%

Multiresidue methods for determination of pesticides using SPME and SPE followed by GC-NPD system: a comparative study

Milhome

Sousa

Keukeleire

et al. 2011

J. Braz. Chem. Soc.

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“…We attributed the low recoveries of PCBs and mirex to their hydrophobic properties. The P ‐values of some of the OC and PCBs are reported in Table . The P ‐value gives a measure of the ability of the polar solvent to extract the analyte of interest.…”

Section: Resultsmentioning

confidence: 99%

Evaluation of lipid removal from animal fats for the determination of organochlorine, pesticides, and polychlorinated biphenyl indicators by gas chromatography with electron capture detector

Andrade

Sacheto

Hoff

et al. 2012

J of Separation Science

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For cleanup of animal fat before GC analysis of organochlorine pesticides and polychlorinated biphenyls, freezing-lipid filtration with solid-phase extraction and matrix solid-phase dispersion were evaluated to replace the official Brazilian methodology that uses preparative alumina column chromatography. General drawbacks associated with this last technique, such as the use of large amounts of solvent, laborious and time-consuming procedure could be avoided by using these alternative approaches. Experiments were carried out to study the performance by using different combinations of sorbents and elution solvents. Efficiency of alternative extraction methods in terms of fat removal and recovery capability was monitored by gravimetry, TLC, and GC with electron capture detection. Freezing-lipid filtration with solid-phase extraction afforded better clean up efficiency with recoveries in a range of 54.5 to 103.6% with the relative standard deviation of less than 10% for all compounds under investigation.

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“…Large structure dyes such as RR 195 generally lead to low degradation efficiency. Silva et al [16] performed a degradation of the red dye ultra RGB and obtained a maximum degradation of 5.5 %. Similarly to RY 145, RR 195 is more resistant to degradation by enzymes, so it is used in long reaction times, other types of microorganisms, or a combination of more than one methodology.…”

Section: Experimental Design For Individual Dyesmentioning

confidence: 99%

“…[15] Turnip peroxidase was used to remove 57 % of the dye Reactive Blue 21. [16] The decolourization of direct dyes in the presence of NaCl was performed by Matto and Husain [17] and 88 % removal was obtained within 1 h of reaction for the dye Direct Red 23.…”

Section: Introductionmentioning

confidence: 99%

Enzymatic reuse of simulated dyeing process effluent using horseradish peroxidase

et al. 2017

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Reactive dyes are complex structures that cause environmental damage when discarded. The aim of this study was to evaluate the reuse of effluent from an enzyme‐catalyzed dyeing process. The main parameters that influence the degradation of the mixture of dyes using the enzyme horseradish peroxidase were studied using response surface methodology: enzyme, hydrogen peroxide, and dye concentrations as well as the pH. The best conditions for the synthetic effluent were then applied to the reuse of the effluent from the dyeing process in laboratory and pilot scales. In the studies in pilot scale a high colour intensity was obtained (ΔE* value of 0.6) and a good washing fastness (4.0). The results obtained indicate that peroxidases could be used for colour removal on an industrial scale to save water and energy in the post‐dyeing process, reusing part of this effluent with the same efficiency as that of a traditional process.

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Profa. Dra. Helena M. C. Ferraz

Cited by 9 publications

References 11 publications

Multiresidue methods for determination of pesticides using SPME and SPE followed by GC-NPD system: a comparative study

Multiresidue methods for determination of pesticides using SPME and SPE followed by GC-NPD system: a comparative study

Evaluation of lipid removal from animal fats for the determination of organochlorine, pesticides, and polychlorinated biphenyl indicators by gas chromatography with electron capture detector

Enzymatic reuse of simulated dyeing process effluent using horseradish peroxidase

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