scholarly journals Facile and Ultrasensitive Determination of 4-Nitrophenol Based on Acetylene Black Paste and Graphene Hybrid Electrode

Nanomaterials ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 429 ◽  
Author(s):  
Quanguo He ◽  
Yaling Tian ◽  
Yiyong Wu ◽  
Jun Liu ◽  
Guangli Li ◽  
...  
Keyword(s):  
Environmental Protection Agency ◽  
Sensitive Detection ◽  
Acetylene Black ◽  
Optimal Conditions ◽  
Protection Agency ◽  
Complex Matrices ◽  
Practical Applications ◽  
Toxic Pollutant ◽  
20 Nm

4-nitrophenol (4-NP) is a hazardous waste and a priority toxic pollutant identified by US Environmental Protection Agency (EPA). Hence, in this paper, a voltammetric sensor was proposed for the direct and sensitive detection of 4-nitrophenol (4-NP) at nanomolar level in complex matrices by using graphene and acetylene black paste hybridized electrode (GR/ABPE). Under optimal conditions, the calibration curve demonstrates a linear relationship for 4-NP in the range from 20 nM to 8.0 μM and 8.0 μM to 0.1 mM separately with the detection limit of 8.0 nM. In addition to it, the performance of the GR/ABPE in practical applications was evaluated by detecting 4-NP in various water samples, and satisfactory recoveries were realized. Therefore, GR/ABPE may have a great potential application for facile and sensitive detection of 4-NP in complex matrices at nanomolar level.

scholarly journals DETERMINAÇÃO DE GLIFOSATO E ÁCIDO AMINOMETILFOSFÔNICO EM ÁGUAS SUPERFICIAIS DO ARROIO PASSO DO PILÃO

2003 ◽  
Vol 13 ◽  
Author(s):  
MARCELO DUTRA DA SILVA ◽  
MARIA DO CARMO RUARO PERALBA ◽  
MARIA LAURA TURINO MATTOS
Keyword(s):  
High Performance Liquid Chromatography ◽  
Environmental Protection Agency ◽  
High Performance ◽  
Herbicide Application ◽  
Protection Agency ◽  
Brazilian Legislation ◽  
Aminomethylphosphonic Acid ◽  
Glyphosate Herbicide ◽  
High Concentrations

Para investigar a presença do herbicida Glifosato na microbacia hidrográfica arroio Passo do Pilão foram coletadas amostras de água em 15 distintos pontos no arroio Passo do Pilão, nos períodos de 30 e 60 dias após a aplicação do herbicida (DAAH), as quais foram analisadas por cromatografia a líquido de alta eficiência (CLAE). As análises revelaram a presença do herbicida nas águas superficiais dessa microbacia, tanto nas amostras após 30 dias de aplicação do Glifosato como nas de 60 DAAH. Concentrações elevadas (acima de 100 ppb) foram detectadas, principalmente em pontos próximos às áreas de intenso cultivo. As concentrações detectadas foram menores que 500 e 700 ppb, limites de concentrações máximas permitidas para o Glifosato pela legislação brasileira e pela Agência de Proteção Ambiental dos Estados Unidos, respectivamente. DETERMINATION OF GLYPHOSATE AND AMINOMETHYLPHOSPHONIC ACID IN SUPERFICIAL WATERS OF ARROIO PASSO DO PILÃO Abstract To investigation the presence of Glyphosate herbicide in Arroio Passo do Pilão watershed, samples of water were collected in 15 distinct points in Arroio Passo do Pilão, in period of 30 and 60 days after herbicide application (DAHA), which were analysed by high performance liquid chromatography (HPLC). The analysis revealed the presence of the herbicide in superficial areas of this watershed, even in the samples after 30 days of Glyphosate applicatication as in 60 DAHA. High concentrations (above 100 ppb) were detected, mainly in points near to intense cultivation areas. The concentrations detected were smaller than 500 and 700 ppb, limits of the maximum concentrations allowed for Glyphosate by the brazilian legislation and by the Environmental Protection Agency of United States, respectivelly.

The Use of Aniline Blue for the Determination of Dead Phytoplankton, Zooplankton and Meroplankton in LC50 Testings After 96 Hours… A Re-Evaluation of the US Environmental Protection Agency Methodology

2004 ◽  
Vol 126 (3) ◽  
pp. 215-218 ◽  
Author(s):  
Balram Seepersad ◽  
Kelvin Ramnath ◽  
Shyam Dyal ◽  
Reeza Mohammed
Keyword(s):  
Environmental Protection ◽  
Environmental Protection Agency ◽  
Staining Technique ◽  
Aniline Blue ◽  
Protection Agency ◽  
Lc50 Value ◽  
The Us ◽  
Visual Observations

There is a need for a reliable staining technique to distinguish between live and dead organisms following LC50 tests. This is especially so in cases where organisms can be stressed or even become unconscious and appear dead to the aided or naked eyes. Visual observations under such conditions can result in an LC50 value shifting to the lower concentration thereby imposing stiffer guidelines for compliance. Aniline blue can only stain individuals which are physiologically dead imposing an accurate live-dead evaluation and producing a true LC50 value. Guidelines imposed using such data will facilitate compliance and provide an accurate value for an LC50.

scholarly journals Determination of sensitivity limit in quantative analysis of polycyclic aromatic hydrocarbons by Gc-ms

2004 ◽  
pp. 111-119 ◽  
Author(s):  
Nikola Marjanovic ◽  
Snezana Kravic ◽  
Zvonimir Suturovic ◽  
Jaroslava Svarc-Gajic
Keyword(s):  
Environmental Protection Agency ◽  
Limit Of Detection ◽  
Gas Chromatography Mass Spectrometry ◽  
Protection Agency ◽  
Selected Ion Monitoring ◽  
Quantitation Limit ◽  
Limit Of Quantitation ◽  
Polycyclic Aromatic ◽  
Individual Pahs

The limit of detection (LOD) and the limit of quantitation (LOQ) for 16 individual PAHs from the Environmental Protection Agency (EPA) list (naphthalene, acenaphthylene, acenaphtene, fluorene, phenanthrene antrachene, fluoranthene, pyrene, benzo(a)anthracene, chrysene benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, dibenzo(a,h) anthracene, benzo(g,h,i)perylene and indeno(1,2,3-cd)pyrene) were determined by Gas Chromatography ? Mass Spectrometry (GC-MS). Determination was performed by SCAN (digital linear scanning) and SIM (selected ion monitoring) techniques preceded by the optimization of the experimental factors. The limit of detection obtained by the SCAN technique was in the range of 0.179 ? 15.236 ng, and the quantitation limit in the range of 1.017 ? 50.788 ng. SIM technique enabled LOD and LOQ in the range of 0.036 ? 13.886 pg and 0.119 ? 46.287 pg respectively.

Determination of the vertical velocity distribution of floatables in CSOs

1999 ◽  
Vol 39 (2) ◽  
pp. 69-73 ◽  
Author(s):  
John Cigana ◽  
Martin Couture ◽  
Charles Meunier ◽  
Yves Comeau
Keyword(s):  
Vertical Velocity ◽  
Environmental Protection Agency ◽  
Control Policy ◽  
Protection Agency ◽  
Combined Sewer Overflows ◽  
Policy Compliance ◽  
Weather Events ◽  
Combined Sewer ◽  
Wet Weather

Control of floatables, since April 1994, is one of the nine minimum controls required by the U.S.EPA (United States Environmental Protection Agency) for CSO (Combined Sewer Overflows) control policy compliance. Municipalities must control and intercept floatables at their overflow sites. Efficient interception of these floatables requires prior characterisation. To accomplish this floatables from the Montréal (Canada) region were intercepted during wet weather events. Many characteristics were analysed, but a special emphasis was given to the measurement of the vertical velocity of the floatables. This vertical velocity was measured using a column that could be rotated around its central axis. Results have shown that 80% of the intercepted floatables have a vertical velocity of over 0.07 m/s.

Immunoassay of Pesticides

1991 ◽  
Vol 74 (2) ◽  
pp. 239-247 ◽  
Author(s):  
Bennett M Kaufman ◽  
Marion Clower
Keyword(s):  
Gas Chromatography ◽  
Solvent Extraction ◽  
Environmental Protection Agency ◽  
Food Matrix ◽  
Protection Agency ◽  
Department Of Agriculture ◽  
International Union ◽  
Professional Societies ◽  
Test Kit

Abstract Determination of the presence and levels of pesticide residues In food Is fundamental In monitoring and regulatory programs. Residues are separated from the food matrix by solvent extraction, followed by cleanup steps. The residues are most often Identified and quantltated by instrumental analysis, usually liquid or gas chromatography. Extraction and cleanup are often laborious and time-consuming; determination requires expensive, sophisticated Instrumentation. There is a need for rapid, easily performed tests, such as Immunoassays, that could be used for screening under field conditions or for quantitation of residues In foods in the laboratory. Although a large number of immunoassays have been developed for pesticide chemicals, very few have been specifically applied to foods, and only a very small number are currently available commercially. The agencies charged with monitoring and regulatory responsibilities—Environmental Protection Agency, Food and Drug Administration, and U.S. Department of Agriculture—as well as professional societies such as AOAC and the International Union of Pure and Applied Chemistry, are Investigating and developing guidelines for test kit evaluation and standards to be met before a kit can be accepted as a practical and useful method of analysis for use In their programs.

Skin Penetration Method Suggested for Environmental Protection Agency Requirements

1989 ◽  
Vol 8 (5) ◽  
pp. 829-835 ◽  
Author(s):  
Robert P. Zendzian
Keyword(s):  
Environmental Protection ◽  
Environmental Protection Agency ◽  
Skin Penetration ◽  
Dermal Absorption ◽  
Male Rats ◽  
Application Site ◽  
Protection Agency ◽  
Blood Concentrations ◽  
Total Urine

The Environmental Protection Agency has circulated a protocol for examining the dermal absorption of pesticides in rats. This protocol will be considered as a guideline for determining the dermal absorption of pesticides. Approximately 40 pesticides have been evaluated with this protocol. Male rats are dosed dermally with labeled pesticide. Doses, in mg/cm2, are applied to the shaven skin of the back as the use product, diluted with water if necessary. The application site is protected with a nonocclusive device. Four rats per dose are exposed for 0.5, 1, 2, 4, 10, or 24 hrs. Samples collected are soap and water wash, skin at the application site, blood, total urine and feces, carcass, and selected tissues. Mass balance calculations include determination of pesticide that can be removed with soap and water, pesticide bound on or in the skin, total pesticide absorbed with time, blood concentrations with time, pesticide accumulation in target tissues, and pesticide excreted.

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