scholarly journals DETERMINATION OF BTEX IN ENVIRONMENTAL SAMPLES: DEVELOPMENT AND PROTECTION OF TECHNOLOGIES AND ANALYTICAL METHODS

2019 ◽  
Vol 16 (31) ◽  
pp. 431-439
Author(s):  
Helilma de Andréa PINHEIRO ◽  
Ana Paula Mota FERREIRA ◽  
Ismael Carlos Braga ALVES ◽  
Antônio Fernandes SANTOS JÚNIOR ◽  
Raquel Bezerra dos Santos SAWCZUK ◽  
...  
Keyword(s):  
Petroleum Hydrocarbons ◽  
Environmental Samples ◽  
Low Cost ◽  
The United States ◽  
Operational Control ◽  
Toxic Compounds ◽  
Chromatographic Techniques ◽  
Benzene Toluene ◽  
And Storage

The contamination of water and soil by petroleum hydrocarbons is reported quite frequently, mainly due to accidents involving transport and storage of fuels. Among the most toxic compounds the most volatile benzene, toluene, ethylbenzene and xylene (BTEX). Residues of these compounds can cause serious environmental and public health troubles. Thus, more sensitive, selective and low-cost techniques, focused on the analysis and monitoring of these contaminants are being developed in order to establish operational control and to comply with local laws, but the intellectual property of such technologies is still unknown. The present study shows the panorama about patents, thesis and dissertations which have been already published on this theme. Together, the United States and China hold the largest number of patents, and most of thesis/dissertations describe methodologies for BTEX detection in water, although numerous environmental problems caused by oils in the soil had been reported. Also, the methods based on chromatographic techniques stand out in relation to the other techniques. It was possible to verify important advances in the field of sensors, especially the electrochemical ones, in order to solve the analytical gaps.

Isolation and Determination of 4‐Nonylphenol in Environmental Samples Using Combined Chromatographic Techniques

2004 ◽  
Vol 27 (19) ◽  
pp. 2997-3012 ◽  
Author(s):  
Renata Gadzała‐Kopciuch ◽  
Beata Berecka ◽  
Tomasz Ligor ◽  
Bogusław Buszewski
Keyword(s):  
Environmental Samples ◽  
Chromatographic Techniques

scholarly journals Potentiometric determination of captopril in pharmaceutical formulations

2003 ◽  
Vol 28 (1) ◽  
pp. 39-44 ◽  
Author(s):  
P. R. da S. Ribeiro ◽  
A. O. Santini ◽  
H. R. Pezza ◽  
L. Pezza
Keyword(s):  
Low Cost ◽  
Standard Procedure ◽  
Pharmaceutical Preparations ◽  
Pharmaceutical Formulations ◽  
Magnesium Stearate ◽  
The United States ◽  
United States Pharmacopoeia ◽  
Glass Ph Electrode ◽  
Tablet Dosage

A simple, precise, rapid and low-cost potentiometric method for captopril determination in pure form and in pharmaceutical preparations is proposed. Captopril present in tablets containing known quantity of drug was potentiometrically titrated in aqueous solution with NaOH using a glass pH electrode, coupled to an autotitrator. No interferences were observed in the presence of common components of the tablets as lactose, microcrystalline cellulose, croscarmellose sodium, starch and magnesium stearate. The analytical results obtained by applying the proposed method compared very favorably with those obtained by the United States Pharmacopoeia Standard procedure. Recovery of captopril from various tablet dosage formulations range from 98.0 to 102.0%.

Evaluation of Ultrasonic Snow Depth Sensors for U.S. Snow Measurements

2008 ◽  
Vol 25 (5) ◽  
pp. 667-684 ◽  
Author(s):  
Wendy A. Ryan ◽  
Nolan J. Doesken ◽  
Steven R. Fassnacht
Keyword(s):  
Snow Depth ◽  
Low Cost ◽  
The United States ◽  
Snow Accumulation ◽  
Depth Sensors ◽  
Automated Method ◽  
Ground Measurement ◽  
Current Requirement ◽  
The Difference

Abstract Ultrasonic snow depth sensors are examined as a low cost, automated method to perform traditional snow measurements. In collaboration with the National Weather Service, nine sites across the United States were equipped with two manufacturers of ultrasonic depth sensors: the Campbell Scientific SR-50 and the Judd Communications sensor. Following standard observing protocol, manual measurements of 6-h snowfall and total snow depth on ground were also gathered. Results show that the sensors report the depth of snow directly beneath on average within ±1 cm of manual observations. However, the sensors tended to underestimate the traditional total depth of snow-on-ground measurement by approximately 2 cm. This is mainly attributed to spatial variability of the snow cover caused by factors such as wind scour and wind drift. After assessing how well the sensors represented the depth of snow on the ground, two algorithms were created to estimate the traditional measurement of 6-h snowfall from the continuous snow depth reported by the sensors. A 5-min snowfall algorithm (5MSA) and a 60-min snowfall algorithm (60MSA) were created. These simple algorithms essentially sum changes in snow depth using 5- and 60-min intervals of change and sum positive changes over the traditional 6-h observation periods after compaction routines are applied. The algorithm results were compared to manual observations of snowfall. The results indicated that the 5MSA worked best with the Campbell Scientific sensor. The Campbell sensor appears to estimate snowfall more accurately than the Judd sensor due to the difference in sensor resolution. The Judd sensor results did improve with the 60-min snowfall algorithm. This technology does appear to have potential for collecting useful and timely information on snow accumulation, but determination of snowfall to the current requirement of 0.1 in. (0.25 cm) is a difficult task.

New Farm Acts and Emerging Market Forms: Implications for Farmers

2021 ◽  
pp. 097639962110308
Author(s):  
Sucha Singh Gill
Keyword(s):  
Emerging Market ◽  
The United States ◽  
Market Regulation ◽  
Food Markets ◽  
Agricultural Produce ◽  
Expected Benefits ◽  
The Government ◽  
The Impact ◽  
And Storage

This article examines the implications of new farm laws enacted by the Government of India in 2020 on farming and farmers. There are divergent opinions of experts and of the Government of India and the farmers’ unions on the expected benefits/losses to farmers. This article seeks guidance from economic theory on determination of prices of inputs and outputs under different market forms. The farm laws raise concerns about their potential to alter the organizational forms of production, marketing and storage of agricultural produce involving big private corporate agencies leading to changes in the market forms for determining prices and output level. These issues need to be examined in the context of emerging monopsony/oligopsony market forms, agricultural produce markets and final consumer level food markets. The discussion is supplemented by empirical evidence from the United States on the impact of similar laws in the 1980s on small farmers, together with limited evidence on the abolition of APMC market regulation in Bihar in 2006, so as to draw some lessons for reforms and their implications of future of farming and farmers in India.

ON THE CAPILLARY GAS CHROMATOGRAPHIC DETERMINATION OF PETROLEUM HYDROCARBONS IN ENVIRONMENTAL SAMPLES

1999 ◽  
Vol 29 (3) ◽  
pp. 281-282
Author(s):  
Jáb Krupčik ◽  
Peter Oswald ◽  
Ivan Špánik ◽  
Eva Benická ◽  
Pavol Daučik
Keyword(s):  
Petroleum Hydrocarbons ◽  
Environmental Samples ◽  
Chromatographic Determination

scholarly journals Spectrophotometric determination of diclofenac in pharmaceutical preparations assisted by microwave oven

2005 ◽  
Vol 30 (1) ◽  
pp. 29-36 ◽  
Author(s):  
E. G. Ciapina ◽  
A. O. Santini ◽  
P. L. Weinert ◽  
M. A. Gotardo ◽  
H. R. Pezza ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Low Cost ◽  
Standard Procedure ◽  
Pharmaceutical Preparations ◽  
Magnesium Stearate ◽  
The United States ◽  
Molar Absorptivity ◽  
Heating Time ◽  
Limit Of Quantification

In this work, an effective and low-cost method for the determination of sodium or potassium diclofenac is proposed in its pure form and in their pharmaceutical preparations. The method is based on the reaction between diclofenac and tetrachloro-p-benzoquinone (p-chloranil), in methanol medium. This reaction was accelerated by irradiating of reactional mixture with microwave energy (1100 W) during 27 seconds, producing a charge transfer complex with a maximum absorption at 535 nm. The optimal reaction conditions values such as reagent concentration, heating time and stability of the reaction product were determined. Beer's law is obeyed in a concentration range from of 1.25x10-4 to 2.00x10-3 mol l-1 with a correlation coefficient of 0.9993 and molar absorptivity of 0.49 x10³ l mol-1 cm-1. The limit of detection (LOD) was 1.35x10-5 mol l-1 and the limit of quantification (LOQ) was 4.49x10-5 mol l-1. In the presence of the common excipients, such as glucose, lactose, talc, starch, magnesium stearate, sodium sulphite, titanium dioxide, polyethyleneglycol, polyvinylpirrolidone, mannitol and benzilic alcohol no interferences were observed. The analytical results obtained by applying the proposed method compare very favorably with those given by the United States Pharmacopeia standard procedure. Recoveries of diclofenac from various pharmaceutical preparations were within 95.9% to 103.3%, with standard deviations ranging from 0.2% to 1.8%.

Calibration of GC-FID and IR Spectrometric Methods for Determination of High Boiling Petroleum Hydrocarbons in Environmental Samples

2004 ◽  
Vol 153 (1-4) ◽  
pp. 329-341 ◽  
Author(s):  
Ján Krupcík ◽  
Peter Oswald ◽  
Drahomír Oktavec ◽  
Daniel W. Armstrong
Keyword(s):  
Petroleum Hydrocarbons ◽  
Environmental Samples

PROBLEMS WITH THE DETERMINATION OF PETROLEUM HYDROCARBONS IN ENVIRONMENTAL SAMPLES

1999 ◽  
Vol 29 (3) ◽  
pp. 279-280
Author(s):  
J´n Krupˇik ◽  
D. Oktavec ◽  
I. Skačáni ◽  
P. Daučik
Keyword(s):  
Petroleum Hydrocarbons ◽  
Environmental Samples
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