Maximum Recovery Percentage Research Articles

Extraction of Bovine Serum Albumin by Aqueous Two-Phase System Using PEG4000/Sodium Citrate and PEG8000/Sodium Phosphate

Aqueous Two Phase System (ATPS) or liquid-liquid extraction is used in biotechnology to recover valuable compounds from raw sources. In Aqueous Two-Phase Systems, many factors influence the Partition coefficient, K, (which is the ratio of protein concentration in the top phase to that in the bottom phase) and the Recovery percentage (Rec%). In this research, two systems of ATPS were used: first, polyethylene glycol (PEG) 4000/Sodium citrate (SC), and the second, PEG8000/ Sodium phosphate (SPH), for the extraction of Bovine Serum Albumin (BSA). The behavior of Rec% and K of pure (BSA) in ATPS has been investigated throughout the study by the effects of five parameters: temperature, concentration of polyethylene glycol (PEG4000 and PEG8000), the concentration of Sodium citrate or Sodium phosphate, pH, and the addition of sodium chloride as a supporting agent. The recovery percentage of BSA and its partition coefficient are significantly influenced by these factors to various degrees. The most influential variable in this study is PEG concentration for both systems. In addition to the PEG concentration, the stabilizing impact of NaCl is a crucial factor. The interaction between biomolecules and PEG gets more hydrophobic as the PEG concentration is raised. In the first system (PEG4000/SC), the maximum recovery percentage and partition coefficient were 98.99% and 97.69, respectively, at 31°C, PEG4000 concentration 1.5g/10 ml, Sodium citrate concentration 2.7 g/10 ml, pH 10, and 0.5 M NaCl concentration. While in the second system (PEG8000/SPH), the maximum recovery percentage and partition coefficient was 98.93% and 92.12, respectively, at 31oC, PEG8000 concentration 1.5 g/10 ml, Sodium phosphate concentration 2.4 g/10 ml, pH 10, and concentration of NaCl 0.5 M.

Development and Application of Chitosan Nanogel as a Sorbent for Methotrexate Extraction

Background: Successful drug extraction from biological fluids is challenging due to interfering factors and the trace levels of the target analytes. background: Today, successful drug extraction, especially in biological fluids, due to interfering factors and the trace level of targeted analytics, faces many challenges in a complex matrix. Therefore, providing a suitable and sensitive method that can be increased the efficacy of extraction method has been considered. Objective: We aimed to provide a suitable and sensitive method to increase the efficiency of methotrexate extraction from biological fluids. objective: In this study, the chitosan-based nanogels, which were synthesized by the ionic gelation method were used for solid-phase microextraction of methotrexate Methods: Chitosan-based nanogel synthesized by the ionic gelation method was used for solidphase microextraction of methotrexate from aqueous and plasma media. The nanogel was characterized in vitro in terms of morphological characteristics (transmission electron microscopy), particle size, polydispersity index (PDI), and zeta potential. High-performance liquid chromatography was used to determine the methotrexate concentrations and extraction yield. method: The in vitro characterization of nanogels were performed by evaluation of morphological characteristics with TEM, determination of particle size, PDI, and zeta potential and also the HPLC assay method for determination of methotrexate concentration in different media and determination of extraction yield Results: A nanogel with an average size of 135.6 nm and PDI of 0.14 was used for the nanoextraction of methotrexate in this study. The methotrexate concentration, nanogel amount, and extraction time affected the extraction yield. Maximum recovery percentages of 75% and 69% were achieved when extracting methotrexate from aqueous and plasma media, respectively. result: The nanogels with the average size of 135.6 nm and PDI of 0.14 were used for nanoextraction of methotrexate in this study. The concentration of methotrexate, amount of nanogel, and time of extraction were evaluated as an essential factor affecting the extraction yield. Conclusion: The high extraction yields in both studied media indicate that using chitosan-based nanogel as a sorbent during the solid-phase microextraction of methotrexate is a promising prospect, with potential uses for other drugs in different media. It seems that using nanogels can be an excellent way to improve the extraction of drugs from biological environments. other: non

Magnetic Dispersive Solid‐Phase Extraction Using Toner Powder for Trace Determination of Heavy Metals in Vegetables and Aqueous Media by FAAS: Box‐Behnken Design

AbstractIn this work, toner powder as a magnetic adsorbent coupled with a dispersive solid phase extraction (DSPE) method was proposed for the pre‐concentration and separation of Pb2+, Cd2+, and Zn2+ in vegetable samples and aqueous environments. Flame atomic absorption spectrometry (FAAS) was used for the final analysis of the ions. Adsorbent characterization was studied by scanning electron microscope (SEM), transmission electron microscopy (TEM), Fourier‐transform infrared spectroscopy (FTIR), X‐ray diffraction analysis (XRD), and vibrating‐sample magnetometer (VSM). The effect of experimental factors on the extraction efficiency was investigated by Box‐Behnken design (BBD). The maximum recovery percentage was found to be 95.40%, 95.40%, and 97.40% for Pb2+, Cd2+, and Zn2+, respectively. In the optimum conditions, the linearity ranges were obtained 12–200, 1–150, 0.4–100 μg L−1 for the Pb, Cd, and Zn ions, respectively. The limit of detection (LOD) of the method was found 3.60, 0.30, and 0.11 μg L−1 for the Pb2+, Cd2+, and Zn2+, respectively. The suggested procedure indicated to be appropriate, cost‐effective, and eco‐friendly for extraction of mentioned metal ions in different vegetables and water samples with high precision and accuracy.

Carbohydrate-based aqueous biphasic systems for biomolecules extraction

Any potential of new biotechnological processes would be assuredly canceled in the absence of efficient separation strategies. This work comprehensively addresses the solutes partitioning behavior in biocompatible carbohydrate-polymer aqueous biphasic systems (ABSs) to explore the separation performance of these systems. The complete liquid–liquid phase diagrams were determined for sucrose/glucose-polypropylene glycol (PPG) ABSs at 25 °C and atmospheric pressure. Then, the partitioning pattern of four biomolecules, including caffeine, codeine, vanillin, and curcumin, was investigated in the carbohydrate-PPG ABSs. The obtained results show that caffeine, vanillin, and curcumin are mostly electrically neutral in the medium of the studied ABSs and preferentially concentrate in the more hydrophobic PPG-rich phase with the maximum partition coefficients (K) of 2.05, 19.75, and 246.37, respectively. However, codeine, being present mainly in the cationic form in the ABSs investigated, has a high tendency for the more hydrophilic carbohydrate-rich phase with the highest K−1 = 16.85. The magnitude of log K values for all the target biomolecules linearly increases by decreasing the water content ratio of the coexisting phases. The maximum value of the caffeine/codeine selectivity index was estimated to be 34.5 at optimum conditions. The best value of K did not necessarily correspond to the maximum recovery percentage (R) because the volume ratio of phases is another factor that can affect the R values. The curcumin partitioning behavior in carbohydrate-propanol ABSs was also investigated to provide a competitive platform. The gathered results indicate that although both carbohydrate-PPG and carbohydrate-propanol ABSs provide satisfactory partitioning performance for vanillin and curcumin, carbohydrate-PPG ABSs own a higher selectivity index for the alkaloids studied.

Recycling and modeling of chromium from sludge produced from magnetic flocculation treatment of chromium-containing wastewater

In this paper, an effective and sustainable treatment method for recycling chromium from sludge produced by magnetic flocculation was established. Chromium was extracted from sludge with hydrogen peroxide and sodium hypochlorite, and then, superparamagnetic ferroferric oxide nanoparticles (MPs) were recovered by magnetic separation. The recovery percentage of chromium with sodium hypochlorite was higher than that with hydrogen peroxide, and the maximum was 99.12%. With increasing MPs use times, the adsorption percentage of chromium decreased, but there was no significant change in the recovery percentage of chromium in sludge. The purity of the recovered sodium chromate crystals was 96.28%. The back-propagation algorithm was used to model chromium recovery. The correlation coefficient between the model prediction data and experimental data was 0.9990, and the average absolute error was 0.51. The maximum recovery percentage of chromium obtained from model prediction was 99.27%, and the corresponding optimal conditions were consistent with those of experiments.

In-situ activated nanoparticle as an efficient and recyclable foam stabilizer for enhancing foam separation of LAS

Linear alkylbenzene sulfonate (LAS) is a particular member of the emerging contaminants, because of its increasingly ubiquitous use and tremendous harm to the environment and wastewater treatment plant. Herein, we develop a novel two-stage foam separation to recover LAS (18.7-91.0 mg/L) from laundry wastewater. We first reported the fabrication of activated silica nanoparticle (SNP) via a facile and scalable in-situ approach. To obtain a desirable surface property, the key design element was the utilization of amphoteric surfactant, viz. cocamidopropyl betaine, as the modifier. In the first-stage, activated SNP could serve as an efficient foam stabilizer to improve the foam stability and the interfacial adsorption of LAS. Remarkably, LAS concentration in effluent decreased to very low levels of 1.9-2.9 mg/L with a proper enrichment ratio, and met the emission standard. In the second-stage, we originally adopted the intensification of liquid drainage to selectively recycle activated SNP from LAS. An inclined foam channel (IFC) covered by hydrophobic coating was constructed and the maximum recovery percentage of SNP reached 91.5%, indicating that the activated SNP was recyclable. This work definitely proves that the integration of nanotechnology in foam separation can make wastewater treatment more efficient and less expensive.

Removal of Dyes from Wastewater by Ceramic Membrane

The current study aimed to investigate the elimination of dyes from sewerage, using microfiltration membrane mechanism. Three dyes were applied, acid yellow-23, disperse blue -79 and acid orange -7. Experiments were performed with feed concentration (40 -120) ppm, feed flow rate (25 -65) l/h and time (0.25 -1.5) h. The membrane used ceramic membrane, constructed as a candle. It was discovered that water flow diminishes with an elevation in running time, feeding oil concentration and enhancing with elevation in the feed flow rate. In addition, it was determined that the elimination (rejection) rate of dyes enhances with elevation in the flow rate, and the elimination (rejection) rate diminishes as time passes. In cross flow microfiltration, the rejection concentration (concentrate) goes up as time passes, with high feed concentration and flow rate. It was also discovered that the modal infusion concentration declines with high feed concentration and working time. In addition, it was found that product rate goes down as time passes and with high feed concentration. Increasing feed concentration of dyes was associated with an increase in the concentration of rejecting solution. The highest elimination of disperse blue -79, Acid Yellow- 23 and acid orange -7, are 97%, 96.4% and 95.8%, respectively. The maximum recovery percentage of disperse blue - 79, acid yellow- 23 and acid orange -7are 57.7%, 58.5% and 59% respectively.

Simultaneous aqueous two-phase flotation of sodium chlorophyllin and removal of sugars from saponified solution of bamboo leaves

An ethanol–tripotassium phosphate aqueous two-phase flotation (ATPF) system was first time studied for the separation of sodium chlorophyllin and sugars. The single factors influencing the recovery of sodium chlorophyllin in the top phase and removal of sugars in the bottom phase were investigated and optimized by response surface methodology (RSM). The maximum recovery percentage (88.28%) of sodium chlorophyllin were obtained at 0.55g/mL of tripotassium phosphate, 25mL/min of nitrogen flow rate, 26min of flotation time and 5mL of ethanol, meanwhile, the removal percentage of sugars reached 95.84%. Compared with aqueous two-phase extraction (ATPE), ATPF showed advantages of low consumption of organic solvent, high enrichment factors, and high separation effect. Sodium chlorophyllin were demonstrated theoretically and experimentally to have surfactivity. Finally, the scale-up experiments were conducted to further prepare sodium copper chlorophyllin, and the absorbance ratio (A406.00nm/A631.00nm) was 3.49. This method may blaze the trail for mass production of sodium copper chlorophyllin in industry.

Efectividad cualitativa del ganado caprino en la dispersión de especies de frutos secos y carnosos

Mancilla-Leyton, J.M., Fernandez-Ales, R., Martin Vicente, A. 2015. Seed dispersal effectiveness of shrubs by goat. Ecosistemas 24(3): 22-27. Doi.: 10.7818/ECOS.2015.24-3.04 We evaluated the role of domestic goats as seed dispersers of eight representative Mediterranean shrub species ( Cistus salviifolius, C. libanotis, Halimum halimifolium, H. calycinum, Myrtus communis, Phillyrea angustifolia, Pistacia lentiscus and Rhamnus lycioides ). Six female goats of similar size and age were fed with fruits of study species. Following fruits ingestion by goats, total faeces were collected at 24-h intervals. The seeds retrieved were tested for germination and viability, along with seeds not eaten by the goats. Less than 30% of the seeds eaten were retrieved from the dung, with significant differences between species. C. salviifolius showing the maximum recovery percentage (30%), and P. lentiscus the minimum (0%). Seed recovery was significantly related to seed hardness. In most species, the maximum amount of seeds recovered occurred 24-72 h after ingestion. The passage through the goat gut significantly increased seed germination in C. salviifolius, H. halimifolium, H. calycinum and P. angustifolia . The results of this study show that goats can potentially favour (Cistaceae) or inhibit (fleshy fruits) seed dispersal of browsed Mediterranean shrub species. Therefore, these results should be considered when developing conservation and restoration plans of natural vegetation in Mediterranean areas.

Simple and efficient approach for recycling of fine acrylic-based superabsorbent waste

Recycling fine particles (smaller than 150 µm) of acrylic-based superabsorbent polymer is of a great importance due to environmental and economic issues. In this paper, fines or dust is agglomerated by soaking in treatment solution containing acetone, water and cross-linker and subsequently curing at 160 °C for 2 h. Bisphenol A diglycidyl ether resin (BADGE), ethylene glycol diglycidyl ether (EGDGE) and polyethylene glycol diglycidyl ether (PEGDGE) have been employed as crosslinking agents. The considered effective parameters includes: cross-linker type and concentration in treatment solution and acetone to water ratio. Swelling capacity in saline and deionized water, absorbency under load (AUL), storage modulus, recovery proportion (percentage of particles above 100-mesh screen) and optical microscope images were utilized to investigate accurately. All the cross-linkers could raise the particle size in 70 and 50 % acetone content by variation of maximum recovery percentages between 70 and 93. The best condition was found for BADGE cross-linker in 70 and 50 % acetone content with appropriate swollen gel strength and absorbencies. Besides both dry and wet agglomeration were firmly integrated. Therefore, crosslinking agglomerated particles is a promising way to recycle fine SAP waste on account of its simplicity and efficiency. Recycling fine particles of acrylic-based superabsorbent polymer waste is of a great importance due to environmental and economic issues. Crosslinking agglomerated particles as a promising approach has been considered to reuse the fine SAP. Three different crosslinking agents were employed to compare their productivity. Swelling capacity in saline and deionized water, absorbency under load (AUL), storage modulus, recovery proportion and optical microscope images were utilized to investigate accurately.

Reverse Osmosis Polyamide Membrane for the Removal of Blue and Yellow Dye from Waste Water

The present work aims to study the removal of dyes from wastewater by reverse osmosis process. Two dyes were used direct blue 6, and direct yellow. Experiments were performed with feed concentration (75 – 450 ppm), operation temperature (30 – 50 oC) and time (0.2 – 2.0 hr). The membrane used is thin film composite membrane (TFC). It was found that modal permeate concentration decreases with increasing feed concentration and time operating, while permeate concentration increases with increasing feed temperature. Also it was found that product rate increase with increasing temperature, but it decrease with increasing feed concentration and time. The concentration of reject solution showed an increase with increasing feed concentration of dyes and feed temperature, while decreases with increasing time operating of reverse osmosis unit. The maximum rejection for direct blue 6 and direct yellow are 98.89% and 98.30% respectively. The maximum recovery percentage for direct blue 6 and direct yellow are 17.84% and 18.20% respectively. The maximum concentration factor of direct blue 6 is 1.227 and for direct yellow is 1.272.

REMOVAL OF HEAVY METALS USING REVERSE OSMOSIS

The aim of this work is to study reverse osmosis characteristics for copper sulfate hexahydrate(CuSO4.6H2O), nickel sulfate hexahydrate (NiSO4.6H2O) and zinc sulfate hexahydrate (ZnSO4.6H2O)removal from aqueous solution which discharge from some Iraqi factories such as Alnasser Company formechanical industries. The mode of operation of reverse osmosis was permeate is removed and theconcentrate of metals solution is recycled back to the feed vessel. Spiral-wound membrane is thin filmcomposite membrane (TFC) was used to conduct this study on reverse osmosis. The variables studied aremetals concentrations (50 – 150 ppm) and time (15 – 90 min). It was found that increasing the time results in an increase in concentration of metal in permeate, feed concentration in feed vessel and recovery percent. While, it was found that water flux, rejection percent and mass transfer coefficient is decreasing with increasing operating time. Also, it was found that the permeate concentration and feed concentration in feed vessel increases with increasing feed concentration, on the contrary, water flux, the percentage of recovery, rejection percent and mass transfer coefficient decreases with increasing the concentration of feed solution. The maximum rejection of copper, nickel, and zinc salts are 96.6%, 95.7% and 98.2% respectively. The maximum recovery percentage of copper, nickel, and zinc salts are 40.8%, 41.35% and 38.44% respectively. The pure water permeability constant was calculated for TFC membrane.

Determination of genetic variability among the isolates of Metarhizium anisopliae var. anisopliae from different geographical origins

The entomopathogenic fungus Metarhizium anisopliae is currently used as an efficient biological control agent against different insects. The prevalence and genetic variability of the entomopathogenic fungus Metarhizium anisopliae var. anisopliae in Asian countries (China, Laos, Singapore and South Korea) and a European country (The Netherlands) was examined. The fungus was found to be widespread in agricultural and forest soils throughout China especially in the south and south western regions, with a maximum recovery percentage of 81.6, while in Laos it was found to be abundant in the forest soils only, the soil of Netherlands also seemed to be an excellent source of entomopathogens with a significant recovery of insect pathogenic fungi. Simple sequence repeats (SSR) and ITS-rDNA sequence data showed that the isolates are closely linked to each other. The gene diversity (He) and polymorphic information content values of sixty two isolates showed mean values of 0.37 and 0.63. The majority of the isolates belonged to one of the closely related genotypes and these were found to be dominant in the agricultural as well as forest ecosystem. Genetic distances among the isolates according to locations and different sources showed minimal variation ranging from 0.23 to 0.34%, with maximum genetic distance of 0.34% among the isolates from Laos and The Netherlands. The reason for the limited variation is uncertain, however even the similarity index among the isolates can endow with sufficient knowledge for the implications of the methods to develop this fungus as a microbial control agent.

A cryopreservation protocol for immature zygotic embryos of species of Ilex (Aquifoliaceae)

Tropical Ilex species have recalcitrant seeds. This work describes experiments demonstrating the feasibility of long-term conservation of Ilex brasiliensis, I. brevicuspis, I. dumosa, I. intergerrima, I. paraguariensis, I. pseudoboxus, I. taubertiana, and I. theezans through cryopreservation of zygotic rudimentary embryos at the heart developmental stage. The embryos were aseptically removed from the seeds and precultured (7 days) in the dark, at 27 +/- 2 degrees C on solidified (0.8% agar) 1/4MS medium, [consisting of quarter-strength salts and vitamins of Murashige and Skoog (1962) medium] with 3% sucrose and 0.1 mg/l Zeatin. The embryos were then encapsulated in 3% calcium alginate beads and pretreated at 24 h intervals in liquid medium supplemented with progressively increasing sucrose concentrations (0.5, 0.75 and 1 M). Beads were dehydrated for 5 h with silicagel to 25% water content (fresh weight basis) and then placed in sterile 5 ml cryovials. Then the beads were either plunged rapidly in liquid nitrogen were they were kept for 1 h (rapid cooling) or cooled at 1 degrees C min(-1) to -30 degrees C. Then the beads were immersed in liquid nitrogen for 1 h (slow cooling). The beads were rewarmed by immersion of the cryovials for 1 min in a water bath thermostated at 30 degrees C. Finally, beads were transferred onto culture medium (1/4MS, 3% sucrose, 0.1 mg/l zeatin, solidified with 0.8% agar) and incubated in a growth room at 27 +/- 2 degrees C under a 14 h light (116 micromol. m(-2) x s(-1))/ 10 h dark photoperiod. Maximum recovery percentages between 15 and 83% (depending on de the species and the treatment) were obtained with the cryopreserved embryos.

Optimization via experimental design of an SPE‐HPLC‐UV‐fluorescence method for the determination of valsartan and its metabolite in human plasma samples

A chemometric approach was applied for the optimization of the extraction and separation of the antihypertensive drug valsartan and its metabolite valeryl-4-hydroxy-valsartan from human plasma samples. Due to the high number of experimental and response variables to be studied, fractional factorial design (FFD) and central composite design (CCD) were used to optimize the HPLC-UV-fluorescence method. First, the significant variables were chosen with the help of FFD; then, a CCD was run to obtain the optimal values for the significant variables. The measured responses were the corrected areas of the two analytes and the resolution between the chromatographic peaks. Separation of valsartan, its metabolite valeryl-4-hydroxy-valsartan and candesartan M1, used as internal standard, was made using an Atlantis dC18 100 mm x 3.9 mm id, 100 angstroms, 3 microm chromatographic column. The mobile phase was run in gradient elution mode and consisted of ACN with 0.025% TFA and a 5 mM phosphate buffer with 0.025% TFA at pH 2.5. The initial percentage of ACN was 32% with a stepness of 4.5%/min to reach the 50%. A flow rate of 1.30 mL/min was applied throughout the chromatographic run, and the column temperature was kept to 40+/-0.2 degrees C. In the SPE procedure, experimental design was also used in order at achieve a maximum recovery percentage and extracts free from plasma interferences. The extraction procedure for spiked human plasma samples was carried out using C8 cartridges, phosphate buffer (pH 2, 60 mM) as conditioning agent, a washing step with methanol-phosphate buffer (40:60 v/v), a drying step of 8 min, and diethyl ether as eluent. The SPE-HPLC-UV-fluorescence method developed allowed the separation and quantitation of valsartan and its metabolite from human plasma samples with an adequate resolution and a total analysis time of 1 h.

Removal and recovery of cationic dyes from aqueous solutions using spherical sulfonic lignin adsorbent

AbstractA novel spherical sulfonic lignin adsorbent, denoted as SSLA, was adopted to removal and recover the cationic dyes from aqueous solutions, e.g., Cationic Red GTL, Cationic Turquoise GB, and Cationic Yellow X‐5GL, and various affecting factors were optimized. It was found that the adsorption of cationic dyes on the adsorbent was initially concentration‐ and temperature‐dependent, and followed both the Freundlich and Langmuir isothermal adsorption. The positives values for ΔH indicated that the process was endothermic. The breakthrough adsorption capacities for GTL, GB, and X‐5GL were 536.0, 550.0, and 582.0 mg/g, respectively, which prevailed over the commercial powdered activated carbon and strongly acidic cation‐exchange resin R732 evidently. Additionally, the maximum recovery percentage could reach 93.2, 97.1, and 96.5% separately for GTL, GB, and X‐5GL, when a mixture of 3.0 mol/L HCl and alcohol with the volume ratio of 1 : 4 was adopted as eluant. Moreover, the results of the mobile desorption and recovery tests indicated that the maximum concentrations of GTL, GB, and X‐5GL in the eluants could reach 13,108, 13,980, and 13,520 mg/L, respectively. Only 6.3, 5.0, and 4.6% of adsorption capacities for GTL, GB, and X‐5GL decreases individually after 20 replicates of adsorption and desorption. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2284–2291, 2006

MultiSimplex and experimental design as chemometric tools to optimize a SPE-HPLC-UV method for the determination of eprosartan in human plasma samples

A chemometric approach was applied for the optimization of the extraction and separation of the antihypertensive drug eprosartan from human plasma samples. MultiSimplex program was used to optimize the HPLC-UV method due to the number of experimental and response variables to be studied. The measured responses were the corrected area, the separation of eprosartan chromatographic peak from plasma interferences peaks and the retention time of the analyte. The use of an Atlantis dC18, 100 mm × 3.9 mm i.d. chromatographic column with a 0.026% trifluoroacetic acid (TFA) in the organic phase and 0.031% TFA in the aqueous phase, an initial composition of 80% aqueous phase in the mobile phase, a stepness of acetonitrile of 3% during the gradient elution mode with a flow rate of 1.25 mL/min and a column temperature of 35 ± 0.2 °C allowed the separation of eprosartan and irbesartan used as internal standard from plasma endogenous compounds. In the solid phase extraction procedure, experimental design was used in order to achieve a maximum recovery percentage. Firstly, the significant variables were chosen by way of fractional factorial design; then, a central composite design was run to obtain the more adequate values of the significant variables. Thus, the extraction procedure for spiked human plasma samples was carried out using C8 cartridges, phosphate buffer pH 2 as conditioning agent, a drying step of 10 min, a washing step with methanol–phosphate buffer (20:80, v/v) and methanol as eluent liquid. The SPE-HPLC-UV developed method allowed the separation and quantitation of eprosartan from human plasma samples with an adequate resolution and a total analysis time of 1 h.

Influence of stone size on seed quality characters of Ber (Ziziphus mauritiana)

The stone of ber (Ziziphus mauritiana) cv. cola were size graded using round perforated metal sieves of size 28/64", 26/64", 24/64"and 22/64". Seed quality characters in terms of germination (%), root and shoot length (cm), dry matter production (mg 10 sl-1) and vigour index were more in medium sized stones compared to large and small sized stones. The maximum recovery percentage, number of seedlings produced per 100 graded stones with 24/64" round perforated sieve are recommended for production of better quality seedlings in ber.