Polyethylene terephthalate conversion into liquid fuel by its co-pyrolysis with low- and high-density polyethylene employing scrape aluminium as catalyst.

The co-pyrolysis of polyethylene terephthalate (PET) with low-density polyethylene (LDPE) and high-density polyethylene (HDPE) was carried out in a batch steel pyrolyzer in order to convert the PET into pyrolysis oil as its pyrolysis alone resulted in wax and gases. The study also aimed to increase the aromatic content of pyrolysis oil by the interaction of degradation fragments of linear chains of LDPE and HDPE with the benzene ring of PET during the pyrolysis. The reaction conditions were optimized for a higher yield of pyrolysis oil which were found to be 500 °C pyrolysis temperature with a heating rate of 0.5 °Cs-1, 1 h reaction time and 20 g of the initial mass of polymer mixture having 20% PET, 40% LDPE and 40% HDPE. Waste aluminium particles were applied as an economical catalyst in the process. The thermal co-pyrolysis yielded 8% pyrolysis oil, 32.3 wax, 39.7 wt% gases and 20% coke while the catalytic co-pyrolysis produced 30.2% pyrolysis oil, 4.2% wax, 53.6 wt% gases and 12% coke. The fractional distillation of catalytic oil resulted in 46% gasoline range oil, 31% kerosene range oil and 23% diesel range oil. These fractions resembled the standard fuels in terms of their fuel properties as well as FT-IR spectra. The GC-MS analysis revealed that the catalytic co-pyrolysis favoured the formation of relatively short-chain hydrocarbons with olefins and isoparaffins as major components while the thermal co-pyrolysis formed long-chain paraffins. The naphthenes and aromatics were also found in higher amounts in the catalytic oil compared with the thermal oil.

Probing the chemical constituents of Cassia javanica and its in vitro analyses as a potent drug.

The phytochemical screening of the crude methanolic stem extracts of Cassia javanica plant showed the presence of different classes of organic compounds like alkaloids, tannins, flavonoids, saponins, phlobatanins, steroids, anthraquinone and cardiac glycoside. The starching frequencies of these functional groups were determined from FT-IR spectroscopic data. The crude and their fractions were examined for antibacterial potential against Klebsiella pneumoniae and Proteus mirabilis. The antibacterial assay showed maximum zone of inhibition for ethyl acetate fraction, i.e. 20 mm against Proteus mirabilis and 18 mm against Klebsiella pneumoniae in the comparison with Levofloxacin used as standard (40 mm). Meanwhile for methanolic crude extract, the inhibition zone was recorded 14 mm against Klebsiella pneumoniae and 22 mm against Proteus mirabilis. The minimum inhibitory concentrations and minimum bactericidal concentrations were recorded as 187.5 µg ml-1 against Proteus mirabilis and 93.75 µg ml-1 against Klebsiella pneumoniae. The scavenging free radical assay was noted as 69.61% at the concentration of 100 ppm.

Metals Contents in Honey, Beeswax and Bees and Human Health Risk Assessment Due to Consumption of Honey: A Case Study from Selected Districts in Khyber Pakhtunkhwa, Pakistan.

Beeswax, honey, and live in-hive worker bees were collected in this study from eight districts in Khyber Pakhtunkhwa, Pakistan. The concentration of seven essential elements (copper, calcium, zinc, iron, nickel, chromium and manganese) and two non-essentials (lead and cadmium) were determined. All of the samples were found to have a random distribution of metal concentrations. The plentiful metals with high concentrations in the gathered samples were discovered to be calcium, iron, and zinc. The health concerns related with metal intake in honey were assessed using the Average Daily Dose (ADD), Hazard Quotients (HQs) and Hazard Index (HI) models. Children were found to have higher estimated health risk values for the components assessed in all samples than adults. All of the computed ADD values were lower than the matching reference (RfD) values. The matching HI values of metals in various honeys were found to be less than one, implying that honey consumption in the studied area has no non carcinogenic risk. Cancer risks (CR) was also calculated for intake of Pb, Cr, Ni and Cd in honey in the selected districts. The CR values for Cr and Cd exceeded 1E-4 in various districts such as Karak, Kohat, Nowshera, Bajur, Dir Upper, and Mohmand Agency, signifying that there was a small danger involved. In the case of Karak, the Ni CR value was greater than the allowed limits. As a result, it is important to keep an eye on the concentration of these metals in honey because anthropogenic input could raise their concentration in the future, posing a health danger.

Health risk assessment of heavy metals via consumption of dietary vegetables using wastewater for irrigation in Swabi, Khyber Pakhtunkhwa, Pakistan.

Health assumptions to the population due to the utilization of contaminated vegetables have been a great concern all over the world. In this study, an investigation has been conducted to ascertain metal concentrations in the wastewater, soil and commonly consumed vegetables from the vicinity of Gadoon Industrial Estate Swabi, Khyber Pakhtunkhwa Pakistan. Physicochemical parameters such as pH, electrical conductivity (EC), total dissolved solids (TDS), total suspended solids (TSS) and total solids (TS) and heavy metals such as Pb, Cr, Cd, Ni, Zn, Cu, Fe, Mn were determined using Atomic Absorption Spectrophotometer (AAS). Moreover, possible health risks due to the consumption of vegetables have also been estimated. pH and TSS in wastewater were found to be higher than the permissible limit set by WHO (1996). These results revealed that Cr concentration in the wastewater was above the permissible limits of United States Environmental Protection Agency (USEPA) which may lead to a detrimental effect on soil quality deterioration, ultimately leading to food contamination. ANOVA analysis demonstrated a significant difference in soil samples for Pb, Cr, Cd, Ni, Zn and Cu at p ≤ 0.001, for Mn at p ≤ 0.05 while no significant difference was observed for Fe respectively. ANOVA analysis also exhibited the highest mean value for Pb, Cr, Cd and Zn in vegetables. A substantial positive correlation was found among the soil and vegetable contamination. The transfer factor for Cr, Pb, Zn, Mn, Ni, Cd and Cu was greater than 0.5 due to contamination caused by domestic discharges and industrial effluents. Health assessment via consumption of dietary vegetables revealed a higher level than the permissible limit (HRI > 1) for Pb and Cd in children and adults. Enrichment factor (EF) due to consumption of vegetables was found higher for Pb and Cr respectively. Based on the findings of this study, there would be a significant risk to the consumers associated with consumptions of vegetables being cultivated in Gadoon Industrial Estate area of district Swabi. Therefore, strict regulatory control measures are highly recommended for the safety of vegetables originated from the study area.

A Validated Spectrofluorimetric Method for the Determination of Moxifloxacin in Its Pure Form, Pharmaceutical Preparations, and Biological Samples.

This research work presents a simple, sensitive, selective, economic, and widely applicable and interferences-free spectrofluorimetric method estimating moxifloxacin in the pure form, commercial formulations and biological samples. The method is based on the reaction of moxifloxacin with Ce(IV) in an acidic medium to generate fluorescent active species Ce(III). The excitation and emission of the fluorescent species are 250 and 362 nm, respectively. Different variables that might influence the oxidation of moxifloxacin, including the Ce(IV) concentration and volume, the effect of temperature and the heating time, the type of acids and its concentration were analyzed and boosted. The linearity was observed in the concentration range of 0.2 - 5.0 µg mL-1 with a correlation coefficient of 0.9991. The limit of detection and the limit of quantification were calculated and observed to be 0.016 and 0.056 µg mL-1 respectively. The effects of the common excipients and some co-administrated drugs usually used in the determination of moxifloxacin were investigated, and no interferences were noted. The planned method has been successfully practical for the analysis of moxifloxacin in its pure form, in pharmaceutical products and in biological samples. The obtained percent recoveries ranged from 95.50 to 101.37% for pharmaceutical products and from 95.15 to 103.18% for human blood plasma and urine.

Investigation of a New Spectrophotometric Method for the Analysis of Ciprofloxacin Based on Microwave Assisted Diazotization.

A microwave-assisted diazotization reaction of ciprofloxacin was used for the analysis of ciprofloxacin in pharmaceutical samples. The ciprofloxacin was diazotized with phenol using acidified sodium nitrite in a domestic microwave oven. Faster microwave heating and microwave effects were found to be very effective for the process of diazotization. The microwave-assisted reaction was initiated in an acidic media and the colored product was stabilized in a slightly basic medium using a NaOH solution as a neutralizer. The product was found to exhibit the maximum absorbance at 440 nm. All of the experimental conditions like the concentration of reagents, microwave power and reaction time were optimized. The optimum concentrations for phenol, sodium nitrite, HCl and NaOH were found to be 140 ppm, 300 ppm, 0.006 M and 0.006 M respectively. The optimum reaction time was found to be 2 min and a medium high power of the microwave was found to be most effective. The limit of detection (LOD) and the limit of quantification (LOQ) were found to be 1.08 and 3.61 mg L-1 respectively. The developed method was successfully applied for the determination of ciprofloxacin in pharmaceutical samples. This new spectrophotometric method for the analysis of ciprofloxacin is fast, sensitive, easy and cost effective.

Production of a highly potent epoxide through the microbial metabolism of 3ß-acetoxyurs-11-en-13ß,28-olide by Aspergillus niger culture.

Context 3ß-Acetoxyurs-11-en-13ß,28-olide (I), a triterpenoid, is found in most plant species. Pharmacologically triterpenes are very effective compounds with potent anticancer, anti-HIV and antimicrobial activities. Objectives Microbial transformation of 3ß-acetoxyurs-11-en-13ß,28-olide (I) was performed in order to obtain derivatives with improved pharmacological potential. Materials and methods Compound (I, 100 mg) was incubated with Aspergillus niger culture for 12 d. The metabolite formed was purified through column chromatography. Structure elucidation was performed through extensive spectroscopy (IR, MS and NMR). In vitro α- and ß-glucosidase inhibitory, and antiglycation potentials of both substrate and metabolite were evaluated. Results Structure of metabolite II was characterized as 3ß-acetoxyurs-11,12-epoxy-13ß,28-olide (II). Metabolite II was found to be an oxidized product of compound I. In vitro α- and ß-glucosidases revealed that metabolite II was a potent and selective inhibitor of α-glucosidase (IC50 value = 3.56 ± 0.38 µM), showing that the inhibitory effect of metabolite II was far better than compound I (IC50 value = 14.7 ± 1.3 µM) as well as acarbose (IC50 value = 545 ± 7.9 µM). Antiglycation potential of compound II was also high with 82.51 ± 1.2% inhibition. Thus, through oxidation, the biological potential of the substrate molecule can be enhanced. Conclusion Biotransformation can be used as a potential tool for the production of biologically potent molecules.

Development of microwave assisted spectrophotometric method for the determination of glucose.

A spectrophotometric method was developed based on the microwave assisted synthesis of Maillard product. Various conditions of the reaction were optimized by varying the relative concentration of the reagents, operating temperature and volume of solutions used in the reaction in the microwave synthesizer. The absorbance of the microwave synthesized Maillard product was measured in the range of 360-740 nm using UV-Visible spectrophotometer. Based on the maximum absorbance, 370 nm was selected as the optimum wave length for further studies. The LOD and LOQ of glucose was found 3.08 µg mL(-1) and 9.33 µg mL(-1) with standard deviation of ±0.05. The developed method was also applicable to urine sample.

Plastic catalytic pyrolysis to fuels as tertiary polymer recycling method: effect of process conditions.

This paper presents results regarding the effect of various process conditions on the performance of a zeolite catalyst in pyrolysis of high density polyethylene. The results show that polymer catalytic degradation can be operated at relatively low catalyst content reducing the cost of a potential industrial process. As the polymer to catalyst mass ratio increases, the system becomes less active, but high temperatures compensate for this activity loss resulting in high conversion values at usual batch times and even higher yields of liquid products due to less overcracking. The results also show that high flow rate of carrier gas causes evaporation of liquid products falsifying results, as it was obvious from liquid yield results at different reaction times as well as the corresponding boiling point distributions. Furthermore, results are presented regarding temperature effects on liquid selectivity. Similar values resulted from different final reactor temperatures, which are attributed to the batch operation of the experimental equipment. Since polymer and catalyst both undergo the same temperature profile, which is the same up to a specific time independent of the final temperature. Obviously, this common temperature step determines the selectivity to specific products. However, selectivity to specific products is affected by the temperature, as shown in the corresponding boiling point distributions, with higher temperatures showing an increased selectivity to middle boiling point components (C(8)-C(9)) and lower temperatures increased selectivity to heavy components (C(14)-C(18)).