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The blood ammonia (NH3) level is one of the most important hepatic biomarkers for the diagnosis and monitoring of liver pathologies and infections. In this work, we developed an optimized optical biosensing method to extract and quantify the ammonia contained in complex-matrix samples emulating the blood serum. First, the approach was tested with solutions of phosphate-buffered saline (PBS) and ammonia chloride. Then, further trials were carried out with solutions of fetal bovine serum (FBS). The ammonia was extracted from the tested samples through a customized cell, and it was optically quantified by exploiting the indophenol reaction. The extraction cell included a cation-exchange membrane in Nafion, which was chemically pre-treated through cleaning procedures of sulfuric acid and hydrogen peroxide to keep a basic pH in the ammonia solution and to avoid contaminants in the membrane. From the NH3 solution, the indophenol reaction produced light-reactive indophenol dye molecules, which were used as colorimetric indicators. Through absorbance measurements of the indophenol dye solution at 670 nm wavelength, we were able to detect and quantify the ammonia level in the samples both with a spectrophotometer and a customized miniaturized read-out system, obtaining a detection limit of 0.029 µmol/mL. [ABSTRACT FROM AUTHOR]

In this study, ammonium was removed from an aqueous solution by using the Emulsion Liquid Membrane technique. The optimum values of the parameters that had effects on the removal process were determined and results were analyzed using statistical methods. As a result of the conducted experiments, it was determined that the volumetric ratio of the emulsion phase was 0.12, the effective internal phase source was H 2 SO 4, the internal phase volumetric ratio was 0.42, the internal phase concentration was 0.36 N, the surfactant ratio was 2 %, the diluent ratio was 34/64 (mineral oil/toluene, %, v/v), homogenizer speed and time were 10,000 rpm and 1 min, agitation speed was 250 rpm, and external phase pH was 10.80. The fact that 98 % yield was achieved in a very short extraction time (15 s) under optimal conditions and the fact that the studies conducted on this subject in the literature are limited and different reveals the importance of this study obviously. [Display omitted] [ABSTRACT FROM AUTHOR]

The blood ammonia (NH3) level is one of the most important hepatic biomarkers for the diagnosis and monitoring of liver pathologies and infections. In this work, we developed an optimized optical biosensing method to extract and quantify the ammonia contained in complex-matrix samples emulating the blood serum. First, the approach was tested with solutions of phosphate-buffered saline (PBS) and ammonia chloride. Then, further trials were carried out with solutions of fetal bovine serum (FBS). The ammonia was extracted from the tested samples through a customized cell, and it was optically quantified by exploiting the indophenol reaction. The extraction cell included a cation-exchange membrane in Nafion, which was chemically pre-treated through cleaning procedures of sulfuric acid and hydrogen peroxide to keep a basic pH in the ammonia solution and to avoid contaminants in the membrane. From the NH3 solution, the indophenol reaction produced light-reactive indophenol dye molecules, which were used as colorimetric indicators. Through absorbance measurements of the indophenol dye solution at 670 nm wavelength, we were able to detect and quantify the ammonia level in the samples both with a spectrophotometer and a customized miniaturized read-out system, obtaining a detection limit of 0.029 µmol/mL.

• Ammonia was extracted and recovered from aqueous solutions as valuable resource. • A mathematical model was developed to predict ammonia-vapour binary transport in VMD. • Trade-off between ammonia selectivity and membrane flux led to optimal feed temperature. • Process driving force decreased as fibre length increased indicated an optimal length. • Permeate gas and membrane surface temperatures were identical until x / L of 0.94. Ammonia is both a contaminant and valuable commodity as chemical. The extraction of ammonia from wastewater was proven technically feasible using membrane distillation (MD). However, the fundamental separation mechanisms of ammonia in MD is not well understood, due to the complexity related to the binary transport and solution chemistry. This study aimed to develop a numerical model for the first time to describe the ammonia and vapour binary transport across hollow fibre membrane in single-stage vacuum membrane distillation (VMD). The key model constants were obtained based on measured membrane properties and unique ammonia chemistry. The modelling results indicated that the ammonia concentration factor into the permeate was strongly correlated with feed temperature at fixed pH but not sensitive to feed concentration. The trade-off between ammonia selectivity and membrane flux indicated a suitable temperature range of 40–45 °C for efficient extraction. The predicted gas pressure of ammonia-vapour mixture showed a slow increase of process driving force and membrane flux with feed temperature. While the averaged process driving force decreased as fibre length increased, indicating an optimal length for maximum permeate production. The predicted permeate gas and membrane surface temperatures were identical along fibre length, indicating minimal conductive heat loss and hence high thermal efficiency (>90%) for ammonia extraction. [ABSTRACT FROM AUTHOR]

Highlights • A modified process for reducing ammonia inhibition of chicken manure is addressed. • Ammonia was rapidly released in the pre-hydrolysis process within the first 3–5 days. • The released ammonia was removed through membrane contactor efficiently. • BMP tests verified the process reduced inhibitory effects and enhanced methane yield. • The proposed process effectively improves the utilization of chicken manure. Abstract This study describes a modified process of ammonia release through pre-hydrolysis – ammonia removal via membrane contactor – methanization for counteracting ammonia inhibition in anaerobic digestion of chicken manure. In the pre-hydrolysis step, ammonia was rapidly released within the first 3–5 days. 78%-83% of the total nitrogen was finally converted into total ammonia/ammonium (TAN) with volatile fatty acids concentration of approximately 300 g/kg·VS. In the ammonia removal process, diluting the hydrolyzed chicken manure to 1:2, the TAN could be reduced to 2 g/kg in 21 h when pH was increased to 9. The final BMP test of chicken manure verified that lower TAN concentration (decreased to 2 g/kg) significantly reduced inhibitory effects, obtaining a high methane yield of 437.0 mL/g·VS. The investigations underlined several advantages of this modified process. [ABSTRACT FROM AUTHOR]

In this paper, the preliminary results of a study aimed to discriminate between the different species of lichens, from which orchil dyes originate, are presented. A multi-analytical approach has been used to analyze several species of lichens, in particular Roccella tinctoria DC, Lasallia pustulata L. and Ochrolechia tartarea L., in an attempt to identify distinguishing markers within different orchil mixtures. In the first part of the research, samples of yarns dyed with the different species, prepared in laboratory after the proper raw lichens treatment, have been subjected to SERS on fiber analyses. Hence an innovative ammonia protocol has been applied to all the specimens. Firstly, in order to evaluate the difference among the different species, HPTLC has been applied to the extracts of dyed yarns and the dye baths. All the spots present on the TLC plates have been analyzed through SERS (HPTLC-SERS), in order to obtain a SERS database of each single compound, fixed on the yarns. Then, HPTLC-MS and HPLC-MS experiments have been carried out, in order to deep into the identification of compounds corresponding to each spot. [ABSTRACT FROM AUTHOR]

Effective utilization of winter bamboo shoot shell (BSS) is of great interest, since BSS provides a renewable and inexpensive bioresource for the production of biofuels. In this study, an effective combination pretreatment by the sequential aqueous ammonia (25 wt%) extraction at 50 °C for 24 h and LiCl/ N, N-dimethyl formamide (LiCl/DMF) (6 wt% of LiCl) pretreatment at 50 °C for 8 h was used for pretreating BSS. SEM, FTIR, and XRD results indicated that combination pretreatment could effectively remove lignin and change the crystal structure of cellulose for promoting enzymatic saccharification. Additionally, significant linear correlations were found about solid recovery-delignification ( R = 0.9235), delignification-reducing sugars ( R = 0.9552), and delignification-hemicellulose removal ( R = 0.9779) during the combination pretreatment. The reducing sugars and glucose from the hydrolysis of 100 g/L pretreated BSS could be obtained at 72.3 and 40.5 g/L, respectively. Using the recovered BSS-hydrolysates containing 20-50 g/L glucose as carbon source, the ethanol yields at 48 h could be obtained at 84.5-86.1% of the theoretical yield. In conclusion, the sequential ammonia extraction and LiCl/DMF pretreatment has high potential application in future. [ABSTRACT FROM AUTHOR]

It is difficult to dissociate Cl by plasma because of the high ionization energy. Since the optical path of Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES) cannot produce a low enough vacuum, the light wave of Cl is absorbed intensively causing difficulty in identifying the characteristic spectrum and subsequently in obtaining an accurate measurement of Cl in geology samples. In this article, a method is described here for completely extracting Cl in marine sediment samples by 10% ammonia with 30 minutes ultrasound bath. The Cl was measured by ICP-AES with an analysis spectrum of 725.670 nm. The detection limit of this method, which was based on ten standard deviations of the blank (10σ, dilution factor=100), was 50 μg/g for Cl. The accuracy and precision of the method were verified by analyzing different geological certified reference materials GBW 07313, GBW 07315 and GBW 07316. The relative standard deviations (RSD, n=7) of the results of independent determination GBW 07316 were 4.3%-8.6%, and relative error (n=7) were 2.9%-7.5%. Compared with traditional methods, this method is simple, fast, easy to perform, and its precision and accuracy are suitable for marine geochemistry.