Analysis of the Products and Decomposition Mechanisms of the Different Organic Impurities in Waste Glass during the Heat-Desiccation Dissociation Process

Introduction: Impurity analysis is an important step in the quality control of pharmaceutical ingredients and final product. Impurities can arise from drug synthesis or excipients and even at small concentrations may affect product efficacy and safety. In this work two methods using high performance liquid chromatography (HPLC) were developed and validated for the evaluation of besifloxacin and its impurity synthesis, with isocratic elution and another with gradient elution. Method: The analysis by HPLC in isocratic elution mode was performed using a cyano column maintained at 25 °C. The mobile phase was composed by 0.5% triethylamine (pH 3.0): acetonitrile (88:12 v/v) eluted at a flow rate of 1.0 ml/min with detection at 330 nm. The gradient elution method was carried out with the same column and mobile phase components only modifying the rate between organic and aqueous phase during analysis. The procedures have been validated according to internationally accepted guidelines, observing results within acceptable limits. Results: The methods presented were found to be linear in the 140 to 260 µg/ml range for besifloxacin and 0.3 to 2.3 µg/ml for an impurity named A. The limits of detection and quantification were respectively 0.07 and 0.3 µg/ml for impurity A, with a 20 µL injection volume. The precision achieved for all analyses performed provided RSD inter-day equal to 6.47 and 6.36% for impurity A with isocratic elution and gradient, respectively. The accuracy was higher than 99% and robustness exhibited satisfactory results. In the isocratic method an analysis time of 25 min and 15 min was obtained for gradient. For impurity A, the number of theoretical plates in the isocratic mode was about 5000 while in the gradient mode it was about 45000, hence, it made the column more efficient by changing the mobile phase composition during elution. In besifloxacin raw material and in pharmaceutical product used in this study, other related impurities were present but but impurity A was searched for and not detected Conclusion: The proposed methods can be applied for quantitative determination of impurities in the analysis of the besifloxacin raw material, as well as in ophthalmic suspension of the drug, considering the quantitation limit.

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Bioremediation of polluted soil due to tsunami by using recycled waste glass

Scientific Reports ◽

10.1038/s41598-021-93806-4 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

M. Azizul Moqsud

Keyword(s):

Heavy Metals ◽

Electrical Conductivity ◽

Laboratory Experiments ◽

Saline Soil ◽

Salt Content ◽

Tohoku Earthquake ◽

Polluted Soil ◽

Waste Glass ◽

Excess Cost ◽

Recycled Waste

AbstractIn this research, bioremediation of tsunami-affected polluted soil has been conducted by using collective microorganisms and recycled waste glass. The Tohoku earthquake, which was a mega earthquake in Japan triggered a huge tsunami on March 11th, 2011 that caused immeasurable damage to the geo-environmental conditions by polluting the soil with heavy metals and excessive salt content. Traditional methods to clean this polluted soil was not possible due to the excess cost and efforts. Laboratory experiments were conducted to examine the capability of bioremediation of saline soil by using recycled waste glass. Different collective microorganisms which were incubated inside the laboratory were used. The electrical conductivity (EC) was measured at different specified depths. It was noticed that the electrical conductivity decreased with the assist of the microbial metabolisms significantly. Collective microorganisms (CM2) were the highly capable to reduce salinity (up to 75%) while using recycled waste glass as their habitat.

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Thermophysical Properties of Cement Mortar Containing Waste Glass Powder

Crystals ◽

10.3390/cryst11050488 ◽

2021 ◽

Vol 11 (5) ◽

pp. 488

Author(s):

Oumaima Nasry ◽

Abderrahim Samaouali ◽

Sara Belarouf ◽

Abdelkrim Moufakkir ◽

Hanane Sghiouri El Idrissi ◽

...

Keyword(s):

Thermal Conductivity ◽

Specific Heat ◽

Thermophysical Properties ◽

Glass Powder ◽

Cement Mortar ◽

Soda Lime ◽

Waste Glass ◽

Soda Lime Glass ◽

Volumetric Specific Heat ◽

Waste Glass Powder

This study aims to provide a thermophysical characterization of a new economical and green mortar. This material is characterized by partially replacing the cement with recycled soda lime glass. The cement was partially substituted (10, 20, 30, 40, 50 and 60% in weight) by glass powder with a water/cement ratio of 0.4. The glass powder and four of the seven samples were analyzed using a scanning electron microscope (SEM). The thermophysical properties, such as thermal conductivity and volumetric specific heat, were experimentally measured in both dry and wet (water saturated) states. These properties were determined as a function of the glass powder percentage by using a CT-Meter at different temperatures (20 °C, 30 °C, 40 °C and 50 °C) in a temperature-controlled box. The results show that the thermophysical parameters decreased linearly when 60% glass powder was added to cement mortar: 37% for thermal conductivity, 18% for volumetric specific heat and 22% for thermal diffusivity. The density of the mortar also decreased by about 11% in dry state and 5% in wet state. The use of waste glass powder as a cement replacement affects the thermophysical properties of cement mortar due to its porosity as compared with the control mortar. The results indicate that thermal conductivity and volumetric specific heat increases with temperature increase and/or the substitution rate decrease. Therefore, the addition of waste glass powder can significantly affect the thermophysical properties of ordinary cement mortar.

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