Biomethanation of a mixture of salty cheese whey and poultry waste or cattle dung

This paper describes the results of a study aimed at improving the efficiency of anaerobic digestion of salty cheese whey in combination with poultry waste or cattle dung. Best results were obtained when salty cheese whey was mixed with poultry waste in the ratio of 7:3, or cattle dung in the ratio of 1:1, both on dry weight basis giving maximum gas production of 1.2 L/L of digester/d with enriched methane content of 64% and 1.3 L/L of digester/d having methane content of 63% respectively. Various conditions such as temperature and retention time have been optimized for maximum process performance.     

Thin-Layer Chromatographic Determination of Diazepam,Phenobarbitone, and Saccharin in Toddy Samples

JPC – Journal of Planar Chromatography – Modern TLC -     

Tuning the size of macrocyclic cavities in trianglimine macrocycles

The synthesis of aromatic dicarboxaldehydes is described along with their reactivity in the [3 + 3] cyclocondensation reaction with (1R,2R)-diaminocyclohexane to give trianglimine macrocycles. In particular, the scope and limitation of the reaction with regard to complete control of the cavity size of the macrocycles is discussed producing a total of 11 macrocycles with different cavity sizes ranging from 9 to 23 angstroms.     

Silver nanoparticles embedded cation-exchange membrane for remediation of Hg species and application as the dip catalyst in organic transformation

Silver nanoparticles (Ag NPs) embedded in poly(perfluorosulfonic) acid cation-exchange membrane (Nafion-211) were synthesized by in situ reductions of Ag⁺ ions by sodium borohydride at room temperature and formamide at 65 °C. The formamide-reduction formed Ag NPs uniformly distributed in the membrane matrix. Therefore, the formamide-reduced Ag NPs embedded membranes were used for the sorption-preconcentration of Mercury (Hg)²⁺ ions by the galvanic reaction with Ag NPs in the membrane matrix. The replacement of Ag⁰ in NPs with Hg²⁺ ions resulted in the formation of Hg⁰ accumulated as nanodroplets in the membrane matrix as indicated by the field emission scanning electron microscopy studies. The sorption of Hg²⁺ ions via galvanic reaction in the Nafion membrane was found to be maximum (>93%) from pH = 2.5 to pH = 6.5. The Ag NPs embedded membrane was studied for Hg²⁺ ions sorption from the aqueous samples by radiotracer (²⁰³Hg), spectrophotometry, energy dispersive X-ray fluorescence and cold vapor atomic absorption spectrophotometry. This membrane was successfully applied for the determination and quantification of Hg²⁺ ions in the real water samples and safe storage of Hg for the remediation objective. The Hg⁰ embedded membrane was also found to be promising as the dip catalyst in the representative organic transformation of phenylacetylene to acetophenone. The Hg⁰ embedded membrane dip catalyst was reused in four consecutive cycles under similar conditions and found to be successful by giving an almost similar yield (%) of the product. This demonstrated a possibility of safe application of Hg⁰ stored in the matrix of poly(perfluorosulfonate) membrane for catalysis.     

Determination of 77 Multiclass Pesticides and Their Metabolitesin Capsicum and Tomato Using GC-MS/MS and LC-MS/MS

A quick, sensitive, and reproducible analytical method for the determination of 77 multiclass pesticides and their metabolites in Capsicum and tomato by gas and liquid chromatography tandem mass spectrometry was standardized and validated. The limit of detection of 0.19 to 10.91 and limit of quantification of 0.63 to 36.34 µg·kg⁻¹ for Capsicum and 0.10 to 9.55 µg·kg⁻¹ (LOD) and 0.35 to 33.43 µg·kg⁻¹ (LOQ) for tomato. The method involves extraction of sample with acetonitrile, purification by dispersive solid phase extraction using primary secondary amine and graphitized carbon black. The recoveries of all pesticides were in the range of 75 to 110% with a relative standard deviation of less than 20%. Similarly, the method precision was evaluated interms of repeatability (RSDr) and reproducibility (RSD_wR) by spiking of mixed pesticides standards at 100 µg·kg⁻¹ recorded anRSD of less than 20%. The matrix effect was acceptable and no significant variation was observed in both the matrices except for few pesticides. The estimated measurement uncertainty found acceptable for all the pesticides. This method found suitable for analysis of vegetable samples drawn from market and farm gates.     

Solubility and solution thermodynamics of 2, 6-bis (4-hydroybenzylidene) cyclohexanone in pure and binary solvents at various temperatures

Solubility of 2, 6-bis (4-hydroxybenzylidene) cyclohexanone (BHBC) in pure solvents such as 1,4-dioxane, methanol, 1-butanol, 1-propanol, ethyl acetate, acetone, tetrahydrofuran (THF), glacial acetic acid, dimethyl sulphoxide (DMSO) and binary solvents dimethyl formamide (DMF) and (1-Propanol + Tetrahydrofuran) were investigated by gravimetric method at different temperature range. The experiment solubility increases with increase in temperature in both pure and binary solvents. The Maximum solubility is found in DMF at 328.15 K and for binary solvent mixture i.e. 1-propanol and THF (0.9 mol fraction) it was maximum at 318.15 K. Further modified Apelblate and Buchowski-Ksiazczak models were used for the theoretical calculation of solubility of BHBC in pure as well binary solvents. A satisfactory correlation of these models with experimental data was observed. The solution thermodynamics parameters like enthalpies, Gibb's free energy of dissolution and entropy of solutions were calculated using Van't Hoff and Gibb's equation, which reveals the solvation mechanism is non-spontaneous and entropy driven.     

A simple high-performance liquid chromatographic method for the estimation of boswellic acids from the market formulations containing Boswellia serrata extract

A simple, rapid, and reproducible reverse-phase high-performance liquid chromatographic method is developed for the estimation of boswellic acids, the active constituents in Boswellia serrata oleo-gum resin. The chromatographic separation is performed using a mobile phase consisting of acetonitrile-water (90:10, % v/v) adjusted to pH 4 with glacial acetic acid on a Kromasil 100 C18 analytical column with flow rate of 2.0 mL/min and detection at 260 nm. The elution times are 4.30 and 7.11 min for 11-keto beta-boswellic acid (11-KBA) and 3-acetyl 11-keto beta-boswellic acid (A-11-KBA), respectively. The calibration curve is linear in the 11.66-58.30 microg/mL and 6.50-32.50 microg/mL range for 11-KBA and A-11-KBA, respectively. The limits of detection are 2.33 microg/mL and 1.30 microg/mL for 11-KBA and A-11-KBA, respectively. The mean recoveries are 98.24% to 104.17% and 94.12% to 105.92% for 11-KBA and A-11-KBA, respectively. The inter- and intra-day variation coefficients are less than 5%. The present method is successfully applied for the estimation of boswellic acids from the market formulations containing Boswellia serrata extract.     

Stereoselective Plasmonic Interaction in Peptide-tethered Photopolymerizable Diacetylenes Doped with Chiral Gold Nanoparticles

Designing polymeric systems with ultra-high optical activity is instrumental in the pursuit of smart artificial chiroptical materials, including the fundamental understanding of structure/property relations. Herein, we report a diacetylene ( DA ) moiety flanked by chiral D - and L -FF dipeptide methyl esters that exhibits efficient topochemical photopolymerization in the solid phase to furnish polydiacetylene ( PDA ) with desired control over the chiroptical properties. The doping of the achiral gold nanoparticles provides plasmonic interaction with the PDA s to render asymmetric shape to the circular dichroism bands. With the judicious design of the chiral amino acid ligand appended to the AuNPs, we demonstrate the first example of selective chiral amplification mediated by stereo-structural matching of the polymer-plasmonic AuNP hybrid pairs. Such ordered self-assembly aided by topochemical polymerization in peptide-tethered PDA provides a smart strategy to produce soft responsive materials for applications in chiral photonics.     

Sonochemical Effect on Activity and Conformation of Commercial Lipases

The enzyme under lower-intensity ultrasonic irradiation leads to favourable conformational changes, thereby enhancing its activity. The augmentation of activity of ultrasound-treated enzyme is strongly dependent on ultrasound intensity, duty cycle and exposure time, which was investigated for commercial lipases. Thermomyces lanuginosus (TL) lipase showed a 1.3-fold enhanced activity after irradiating at 22 kHz and 11.38 W cm^?2 with 50 % duty cycle for 25-min ultrasonic treatment and 1.5-fold enhanced activity was observed for lipozyme (candida antarctica lipase B (CALB)) lipase, at 22 kHz and 15.48 W cm^?2 with 66.67 % duty cycle for 20-min ultrasonic treatment. After sonication, thermodynamic parameters viz. E _a, ΔH, ΔS and ΔG were evaluated and values were found to be significantly lower for both lipases. In addition, the changes in secondary structure due to sonication were investigated by using Fourier transform infrared (FT-IR), which revealed increase in a certain number of random coiled structure, loss of β-sheets, β-turns and α-helix content in TL lipase and CALB lipase. Also, fluorescence spectroscopy exhibited the increased number of tryptophan on surface of both lipases. Moreover, particle size distribution after sonication also helped to improve surface area and enhanced mass transfer, which contributed to improvement in lipase activity.     

Nanocellulose for biosorption of chlorpyrifos from water: chemometric optimization,kinetics and equilibrium

The study explores the biosorption potential of nanocellulose (NC) to remove an insecticide, chlorpyrifos (CP), from aqueous solutions using the batch method. Biosorption kinetics were very fast and reached equilibrium in 60 min, and the experimental kinetic data had fit well with the pseudo-second-order model. Film diffusion was the rate-limiting step for the biosorption of CP onto crystalline nanocellulose (CNC). The equilibrium sorption was well described by the Sips and Langmuir isotherm models. The values of maximum sorption capacities (7.237–5.017 mg/g for the Sips and 12.325–7.247 mg/g for the Langmuir model) decreased with an increase in temperature from 288 to 308 K, signifying biosorption of CP is an exothermic process. Based on the central composite design (CCD), two-factor interaction (2FI) and quadratic models, the correlation between the effects of variable parameters on the CP biosorption onto NC was evaluated. The chemometric analyses suggested that 1.5 g/l NC required 20 min to biosorb 5 mg/l CP to yield an efficiency of 99.3%. Overall, the results demonstrated that NCs can be a promising biosorbent for the removal of pesticides from aqueous streams.