Antiaflatoxigenic activity of Carum copticum essential oil

Plants are unique sources of useful metabolites. Plant essential oils display a wide range of antimicrobial effects against various pathogens. Here, we studied the essential oil from the seeds of Carum copticum. We monitored aflatoxin by high-performance liquid chromatography. Results show that Carum copticum essential oil inhibits Asergillus parasiticus growth and prevents aflatoxin production. The half-maximal inhibitory concentration (IC(50)) is 127.5 μg mL(−1) for aflatoxin B(1) and 23.22 μg mL(−1) for aflatoxin G(1). Our findings show that Carum copticum essential oil is a potential candidate for the protection of foodstuff and feeds from toxigenic fungus growth and their subsequent aflatoxin contamination

Modern Sample Preparation Techniques: A Brief Introduction

Due to fast growth in microprocessors, analytical instrumentations in spectroscopy, chromatography, microscopy, sensors and microdevices have been subjected to significant developments. Despite these advances, a sample preparation step is indispensable before instrumental analysis. Main reasons are low sensitivity of the instruments, matrix interferences and incompatibility of the sample with the analytical device. Most of the time spent and most of the errors occurring during a chemical analysis is on sample preparation step. As a result, any improvements in this essential process will have a significant effect on shortening the analysis time and its precision and accuracy and lowering the cost. This introductory chapter intends to draw the readers’ attention to the importance of sample preparation, the procedures of sampling and the source of errors that occur in the course of sampling. The chapter then continues with a heading on sample preparation techniques, including exhaustive and non-exhaustive methods of extraction. Microwave, sonication and membrane-based extraction techniques are more emphasized as exhaustive methods and under a new title, miniaturized methods are discussed. Automation, on-line compatibility and simplification is an important aspect of any sample preparation and extraction which is discussed at the end of this chapter

Numerical Modeling of Capacitive Deionization Desalination and Studying the Effect of Effective Parameters on Its Performance

Due to the lack of fresh water, production of potable water is one of the important issues for mankind. Capacitive deionization is one of the methods that has recently attracted the attention of researchers due to its simplicity, low price and low energy consumption. The main challenge of this method is high energy consumption at high water concentrations. Therefore, this paper aims to investigate the effect of different effective parameters to improve the system performance. These parameters include feeding voltage, process time, electrode surface area and its capacitance value, overall transfer coefficient, volumetric flow rate and concentration of the feed water, and micropores’ volume, whose effects on energy consumption and number of cycles required to produce potable water are investigated. Results showed that the electrode capacitance and micropores’ volume decreased the necessary process cycles (reducing desalination process time) to produce potable water without significant changes in the energy consumption. The feeding voltage, volumetric flow rate and concentration of the feed water significantly affected the process time and energy consumption. For feed water concentration between 5 and 25 mM, results showed that the minimum values for the desalination process time, electrode surface area, and overall transfer coefficient, are 400 s, 50 cm2 and 0.9 µm/s, respectively. To improve the performance of desalination process in the capacitive deionization cell, development on the physical properties (increasing micropores) and the electrical properties (increasing capacitance value) of the electrodes, as the most important parameters, is suggested

Effect of Laminar Pulsatile Fluid Flow on Separation of Volatile Organic Compounds from Aqueous Solution by a Hollow Fiber Membrane-Based Process

In this study, a laminar pulsatile fluid flow was used for the separation of benzene, toluene, ethylbenzene, and xylene isomers (BTEX) from aqueous solutions. Polyether sulfone hollow fiber membrane has been applied to this process. The effects of BTEX concentration, and feedand extraction flow rates were examined. It was found that the application of the pulsatile fluid flow with the frequency of 0.5 Hz improved the separation process significantly, and the removal efficiency increased more than twice. Moreover, the results showed that BTEX separation under pulsatile fluid flow was affected by the feed flow rate, extraction flow rate, and the BTEX concentration, as well. Validerad;2022;Nivå 2;2022-11-29 (sofila);Funder: University of Sistan and Baluchestan (grant no. G1394/3); PolishNational Agency for Academic Exchange (grant no. PPN/ULM/2020/1/00014/DEC/1)</p

Application of a Novel Micro-Cloud Point Extraction for Preconcentration and Spectrophotometric Determination of Azo Dyes

A novel room temperature micro-cloud point extraction procedure using triton X-114 surfactant as extracting phase was developed for preconcentration and extraction of three azo dyes (orange G, methyl orange, and acid red 18) from aqueous samples using molecular absorption spectrophotometry in the visible region. The effects of different parameters such as concentration of surfactant and added salting out reagent (Na 2 SO 4 ), pH and type of diluting solvent on microextraction were studied and optimized. Under optimum conditions, calibration curves were linear in the range of 2.0-10.0, 0.2-1.0 and 2-12 mg L -1 with the detection limit of 1.6, 0.6 and 111.0 μg L -1 for orange G, methyl orange and acid red 18, respectively. The relative standard deviation was better than 13.12%. The method was applied to the determination of the azo dyes in water samples. Keywords: micro cloud point extraction, orange G, methyl orange, acid red 18, water analysis Introduction The importance of synthetic dyes in today industries can&apos;t be denied. 1 Every year, thousands tons of such dyes are consumed in food, paper, leather, and textile industries. 2,3 From these industries, large volumes of dyes are released to environment and find their way to water and soil. Environmental pollution with dyes can have dire effect on animal, plants, and human health. 8 So far azo dyes have found many applications. Some azo dyes are quite harmful and poisonous, 10 Therefore the importance of their removal/decolorization 11-13 and their determinations In this paper MCPE was successfully applied for the determination of three azo dyes, orange G, methyl orange, and acid red 18 Experimental Instrument A Shimadzu UV-Vis spectrophotometer, UV-160 (Kyoto, Japan), equipped with two microcells (10 μL capacity, Starna, UK, catalog No. 16.10-Q-10/Z15) was used for measuring the absorbance and recording the spectra. A Metrohm (Herisau, Switzerland) model EasySeven pH meter was used for pH measurements and a Behdad centrifuge (Tehran, Iran) was applied for centrifugation. Reagents and chemicals All chemicals were of analytical grade and were purchased from Merck KGaA (Darmstadt, Germany). They were used as received. Triton X-114 (2%, v/v) and Na 2 SO 4 (5%, m/v) solutions were prepared in doubly distilled water. Stock solutions of each dye containing 500 mg L -1 dye, were prepared by dissolving 0.050 g of dye in 100 mL doubly distilled water, individually. Working solutions were obtained by daily dilution of the stock solutions. Micro cloud point extraction procedure An aliquot of the sample solution containing appropriate amounts of dyes was transferred into a centrifuge test tube with conical bottom and proper volume of 2% (v/v) triton X-114 and 0.5 mL phosphate buffer was added to it. To form a cloudy solution, 0.5 mL of Na 2 SO 4 solution (5%, m/v) was added to the mixture. Immediately after the addition of salt, the solution became cloudy. Then it was made up to 10 mL with double distilled water and went under centrifugation for a few minutes at 4000 rpm. The enriched micellar phase, settled at the bottom of the test tube, was around 30-35 μL, of which 20 μL was transferred to a vial and dissolved in 40 μL of the diluting solvent. 10 μL of this mixture was transferred to a microcell for spectrophotometric determination in the desired wavelength. Results and Discussion Absorption spectra The absorption spectra of three analytes in the solution obtained after application of the MCPE under optimized condition were recorded at the wavelength range of 400 to 800 nm against the reagent blanks as shown in Optimization of MCPE To improve the extraction efficiency, important experimental parameters which can potentially affect 1523 Vol. 27, No. 9, 2016 the enrichment performance, such as pH of sample solution, concentration of salt, kind of diluting solvents, concentration of the surfactant, and centrifugation time have been investigated and optimized for proposed MCPE. The univariant method was used to simplify the optimization procedure. A series of experiments were designed for this goal as discussed below. Number of replicates of analysis was at least three for each experiment. Effect of pH The effect of pH on extraction efficiency of dyes was investigated closely. pH of the sample solutions were adjusted either by 0.1 mol L -1 HCl or 0.1 mol L -1 NaOH solutions in the range of 3.0 to 9.5. After then, 0.5 mL Na 2 SO 4 (5%, m/v) and 0.5 mL triton X-114 (2%, v/v) was added to the solution and the extraction was carried out as described earlier. Based on the obtained results shown in Effect of salt concentration In the proposed MCPE, the formation of micelles which are necessary for extraction of analytes, takes place in brine solution. Therefore the concentration of salt can have great effect on extraction of analytes. Among the salts tested for this purpose (NaCl, KCl, K 2 SO 4 and Na 2 SO 4 ), Na 2 SO 4 showed the best effect on forming the turbid solution as was expected since it can imply more ionic strength on aqueous solution; therefore it was chosen for further experiments. Different brine sample solutions containing different concentration of sodium sulfate in the range of 0.125-1.00% (m/v) were prepared and to these solutions 0.5 mL triton X-114 (5%, m/v) and 0.5 mL suitable buffer was added. Higher concentrations of salt were not applied because it was observed that in high concentrations, dilution of the enriched phase takes place with difficulty. This is because the micelles in such media do not tend to dissolve in organic solvent (Supplementary Information section, Selection of diluting solvent Before determination of analytes by spectrophotometer, it is necessary to decrease the viscosity of the surfactant rich-phase in a polar organic solvent to make easier to manipulate it. For this purpose, some conventional organic solvents including acetone, ethanol, methanol, and acetonitrile were investigated and 20 μL of enriched micellar phase was diluted with 40 μL of solvent before spectrophotometric determination. The obtained data showed that methanol, acetonitrile, and acetone were the best solvents for orange G, methyl orange, and acid red 18, respectively (Supplementary Information section, Effect of concentration of triton X-114 The extractant phase in cloud point extraction is a surfactant. Because of its availability, low cost, non-toxic, and non-flammable properties, triton X-114 as the non-ionic surfactant, is the mostly used surfactant in cloud point extraction. 51 Therefore we also selected this surfactant as a green reagent for MCPE. The concentration of triton X-114 can affect the extraction efficiency and enrichment factor. In order to optimize its concentration, different amounts of triton X-114 (0.05-0.2%, v/v) were subjected to the same MCPE procedure on sample solutions containing 0.5 buffer and 0.5 mL Na 2 SO 2 5%. At concentrations more than 0.1% v/v triton X-114, we had a decrease in the absorbance Application of a Novel Micro-Cloud Point Extraction J. Braz. Chem. Soc. 1524 of orange G and methyl orange which was probably due to the dilution of the analyte in larger volume of enriched micellar phase, and for acid red 18, the absorbance remained relatively the same. Accordingly, 0.1% (v/v) of triton X-114 was chosen as the best concentration of surfactant for all analytes Effect of the centrifugation time Since separation of micellar enriched phase and aqueous phase takes place very slowly, similar to CPE, we utilized centrifugation for this purpose. For this, similar sample solutions (0.25% triton X-114, 0.5 mL buffer, 0.25% Na 2 SO 4 ) were prepared and after formation of cloudy solution, they were subjected to centrifugation under different times (3 to 9 min). Aside from maximum absorbance of analytes, the volume and purity of the sedimented phase were also considered as important parameters. The best time of centrifugation was found to be 8 min for orange G, 6 min for methyl orange, and 5 min for acid red 18 at 4000 rpm (Supplementary Information section, (1) Analysis of real samples The MCPE procedure was applied on tap water and wastewater, as for standard solutions. Wastewater samples (from the recycling waste water system of The University of Sistan and Baluchestan) were filtered through 0.45 μm nylon membranes prior to analysis. Since no dye pollution was observed in both samples, the samples were spiked with 3 different concentrations of each dye to investigate the matrix effect on their determination. The results are shown in Conclusions In this study, a fast, economical and easy to operate 1525 Vol. 27, No. 9, 2016 method based on micro-cloud point extraction for preconcentration and determination of traces of three azo dyes (orange G, methyl red and acid red 18) is presented. This is the first report of determination of these dyes with cloud point procedure. Triton X-114 was used as a nonionic and green extractant solvent. In comparison to the similar methods of extraction, MCPE is less expensive, more environmental friendly and faster. In this paper we coupled our MCPE method with spectrophotometry equipped with microcells, as an inexpensive, fast and available instrument; therefore, we successfully minimized toxic organic solvents consumption and increased the sensitivity for the determination of the target analytes. Since spectrophotometric instrumentations are simple, inexpensive and mostly available in common laboratories, the proposed MCPE method is applicable in ordinary laboratories without need of expert personnel. Despite the fact that due to the power of carrying out the separation, organic dyes are mostly determined by HPLC; however, it is an expensive instrument which uses pure, toxic organic solvent. On the other hand, the main drawback of the developed MCPE is relatively high RSD values due to the use of microcells

Microplastics removal from aqueous environment by metal organic frameworks

Abstract This paper provides an overview of recent research performed on the applications of metal–organic frameworks (MOFs) for microplastics (MPs) removal from aqueous environments. MPs pollution has become a major environmental concern due to its negative impacts on aquatic ecosystems and human health. Therefore, developing effective and sustainable methods for removing them from aqueous environments is crucial. In recent years, MOFs have emerged as a promising solution for this purpose due to their unique properties such as high surface area, renewability, chemical stability, and versatility. Moreover, their specific properties such as their pore size and chemical composition can be tailored to enhance their efficiency in removing MPs. It has been shown that MOFs can effectively adsorb MPs from aqueous media in the range of 70–99.9%. Besides some high price concerns, the main drawback of using MOFs is their powder form which can pose challenges due to their instability. This can be addressed by supporting MOFs on other substrates such as aerogels or foams. Meanwhile, there is a need for more research to investigate the long-term stability of MOFs in aqueous environments and developing efficient regeneration methods for their repeated use