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The color of emeralds is predominantly influenced by the concentration of Cr3+. However, the evaluation of the trend of green color depth of emeralds, based on the practical single crystal synthesis with several instrumental analysis is not investigated in previous researches. Specifically, if the Cr2O3 content is controlled to be in the range of 0.2–0.4 wt%, then emeralds can be synthesized with the most esthetically pleasing color. Therefore, the effect of Cr2O3 concentration within the aforementioned range on the color of emeralds is studied using powder X‐ray diffractometry, digital microscopy, electron probe microanalysis, and micro‐spectrophotometry to understand how to achieve the most esthetically pleasing color. As a result, detailed behaviors relating to the absorbances, L*, a*, and b* values, and the relationship between the emerald crystal color changes and increases in Cr2O3 concentration are elucidated. Notably, the absorbance, L* and a* values change significantly when the Cr2O3 concentration is low (0.00–0.236 wt%). However, the changes in these values are moderate when the Cr2O3 concentration is higher (0.236–0.504 wt%). [ABSTRACT FROM AUTHOR]

Highlights • Developed single injection ion-exclusion/cation-exchange chromatography (IEC/CEC). • Ionic species and ethanol were determined with optimal chromatographic resolutions. • IEC/CEC could provide malt amount, bottling method type, and ethanol concentration. • IEC/CEC could analyze ions in 30 different beer samples. Abstract Multicomponent simultaneous analysis is important for management programs, which are required in beer industries because the beer constituents measure by combining several methods in the present. In response to a requirement, our research group developed single sample injection ion chromatography systems, which comprise ion-exclusion/cation-exchange chromatography (IEC/CEC) and post-column derivatization and show promise for simultaneously determining concentrations of organic and inorganic species and alcohol commonly found in beer. Optimal chromatographic resolutions for determining 17 different species in beer samples by IEC/CEC were obtained on a H+-formed weakly acidic cation-exchange resin column with an eluent comprising 2 mM phthalic acid and 1 mM 18-crown-6. Consequently, the usefulness of developed method for monitoring beer samples was demonstrated in terms of beneficial information such as dependency of K+ concentration on the malt amount, influences of organic anion concentrations on different types of bottling methods, and validation of ethanol concentrations displayed in the ingredient table. [ABSTRACT FROM AUTHOR]

The Japanese traditional pot-distilled spirit shochu has various tastes that are produced by variations in the manufacturing processes. In this study, an alcohol-stimulative taste was organoleptically evaluated using shochu samples, and the chemical components and proton nuclear magnetic resonance (1H NMR) spectra were measured. In some shochu samples, the alcohol-stimulative taste was weaker than that of the standard 15% (v/v) EtOH–H 2 O mixture, and the water–ethanol hydrogen-bonding structure was stronger compared to a water–ethanol solution. However, some shochu samples filtered with ion-exchange resin had a strong alcohol-stimulative taste comparable to that of the standard 15% (v/v) EtOH–H 2 O mixture, and the hydrogen-bonding structure was found to be similar to that of the water–ethanol solution. We also investigated the effect of MgCl 2 on reducing the alcohol-stimulative taste, and it was observed most strongly with in shochu samples filtered with ion-exchange resin. The change in chemical shift values of the 1H NMR spectra was also the largest in ion-exchange resin filtered shochu samples. The sensory reduction in the alcohol-stimulative taste could be enhanced by the strengthening of the water–ethanol hydrogen-bonding structure. Shochu samples contained many components in larger quantities compared to vodkas. It was found that MgCl 2 could reduce the alcohol-stimulative taste of shochu samples. Some salts, such as MgCl 2 , can be introduced into spirits through the water used to dilute the ethanol content before bottling the products. Our results indicated that some components, such as MgCl 2 , present in water used can reduce the alcohol-stimulative taste of different spirits produced worldwide. • The alcohol-stimulative taste of Japanese spirit "shochu" was investigated. • Shochu filtered with ion-exchange resin had a strong alcohol-stimulative taste. • MgCl 2 reduced the alcohol-stimulative taste of shochu. • MgCl 2 strengthened the water–ethanol hydrogen-bonding structure of shochu. • Components in water can reduce the alcohol-stimulative taste of spirits worldwide. [ABSTRACT FROM AUTHOR]

Abstract: The simultaneous spectrophotometric determination of phosphate and silicate ions in river water was examined by using ion-exclusion chromatography and post-column derivatization. Phosphate and silicate ions were separated by the ion-exclusion column packed with a polymethacrylate-based weakly acidic cation-exchange resin in the H+-form (TSKgel Super IC-A/C) by using ultra pure water as an eluent. After the post-column derivatization with molybdate and ascorbic acid, so-called molybdenum-blue, both ions were determined simultaneously by spectrophotometry. The effects of sulfuric acid, sodium molybdate and ascorbic acid concentrations and reaction coil length, which have relation to form the reduced complexes of molybdate and ions, on the detector response for phosphate and silicate ions were investigated. Under the optimized conditions (color-forming reactant, 50mM sulfuric acid–10mM sodium molybdate; reducing agent, 50mM ascorbic acid; reaction coil length, 6m), the calibration curves of phosphate and silicate ions were linear in the range of 50–2000μgL−1 as P and 250–10,000μgL−1 as Si. This method was successfully applied to water quality monitoring of Kurose-river watershed and it suggested that the effluent from a biological sewage treatment plant was significant source of phosphate ion in Kurose-river water. [Copyright &y& Elsevier]

In this study, ion-exclusion/cation-exchange chromatography (IEC/CEC) using dual-ion-exchange groups (carboxy and sulfo groups) for the simultaneous determination of anions (SO42−, Cl−, NO3−, and HPO42−) and cations (Na+, NH4+, K+, Mg2+, and Ca2+) was developed. By using the combination of dual-ion-exchange groups, simultaneous separation of inorganic ions with HPO42− was achieved that was impossible by the conventional IEC/CEC based on the single-ion-exchange group (carboxy group). This method was applied to the monitoring of inorganic ionic nutrients in fertilizer solution samples in hydroponic culture. As a result, a higher peak resolution of inorganic anions and cations with phosphate ion using IEC/CEC with dual-ion-exchange groups was achieved in the absence of matrix effects. In addition, the developed method helps to understand the behavior of ionic nutrients in fertilizer solution during hydroponic cultivation and is potentially useful for the individual fertilization of ionic nutrients. [ABSTRACT FROM AUTHOR]

Nutrient availability in hydroponic solutions must be accurately monitored to maintain crop productivity; however, few cost-effective, accurate, real-time, and long-term monitoring technologies have been developed. In this study, we describe the development and application of cation-/anion-exchange chromatography with a neutral eluent (20-mmol/L sodium formate, pH 7.87) for the simultaneous separation (within 50 min) of ionic nutrients, including K+, NH4+, NO2−, NO3−, and phosphate ion, in a hydroponic fertilizer solution. Using the neutral eluent avoided degradation of the separation column during precipitation of metal ion species, such as hydroxides, with an alkaline eluent and oxidation of NO2− to NO3− with an acidic eluent. The suitability of the current method for monitoring ionic components in a hydroponic fertilizer solution was confirmed. Based on our data, we propose a controlled fertilizer strategy to optimize fertilizer consumption and reduce the chemical load of drained fertilizer solutions. [ABSTRACT FROM AUTHOR]

[Display omitted] • A closed-flow photocatalytic system with O2 supply is developed. • The system is applied to recover gallium radioisotopes from complexes. • Capillary electrophoresis is suitable for the quantification of byproducts. This report describes the development and application of a flow photocatalytic reactor for the effective photodecomposition of organic compounds and the recovery of a targeted metal ion; specifically, we describe the decomposition of a gallium-ethylenediaminetetraacetic acid (Ga-EDTA) complex. The system includes a scrubber, which increases the amount of dissolved oxygen in the solution before entering the photocatalytic reactor. First, the decomposition efficiency of the developed reactor is evaluated using dimethyl sulfoxide (DMSO). The decomposition of DMSO is accelerated upon introducing oxygen from the scrubber into the flowline. Second, we employ this system for the decomposition of Ga-EDTA and evaluate the recovery of a Ga radioisotope (RI), which can serve as a probe in positron emission tomography for medical diagnoses. The byproducts generated during Ga-EDTA photodecomposition are monitored by capillary electrophoresis, and the released Ga3+ concentrations are determined by inductively coupled plasma atomic emission spectroscopy for the stable isotope of Ga and with a scintillation detector for RI-Ga. After 30 min under ultraviolet irradiation, 54 % of the RI-Ga released during the photodecomposition of RI-Ga-EDTA was recovered. [ABSTRACT FROM AUTHOR]

Abstract: We describe the ion chromatographic separation of inorganic anions using a diol-stationary phase column (–CH(OH)CH2OH; diol-column) without charged functional groups. Anions were separated using acidic eluent as in typical anion-exchange chromatography. The retention volumes of anions on the diol-column increased with increasing H+ concentration in the eluent. The anion-exchange capacities of diol-columns in the acidic eluent (pH 2.8) were larger than that of zwitterionic stationary phase column but smaller than that of an anion-exchange column. The separation of anions using the diol-column was strongly affected by the interaction of H+ ions with the diol-functional groups and by the types of the eluents. In particular, the selection of the eluent was very important for controlling the retention time and resolution. Good separation was obtained using a diol-column (HILIC-10) with 5mM phthalic acid as eluent. The limits of detection at a signal-to-noise ratio of 3 ranged from 1.2 to 2.7μM with relative standard deviations (RSD, n =5) of 0.04–0.07% for the retention time and 0.4–2.0% for the peak areas. This method was successfully applied to the determination of H2PO4 −, Cl−, and NO3 − in a liquid fertilizer sample. [Copyright &y& Elsevier]

The preservatives benzoic acid and sorbic acid are generally quantified with separation techniques, such as HPLC or GC. Here we describe a new method for determining these compounds in processed food samples based on a narrowness of the UV–visible spectral band width with derivative processing. It permits more selective identification and determination of target analytes in matrices. After a sample is purified by micro dialysis, UV spectra of sample solutions were measured and fourth order derivatives of the spectrum were calculated. The amplitude between the maximum and minimum values in a high-order derivative spectrum was used for the determination of benzoic acid and sorbic acid. Benzoic acid and sorbic acid levels in several commercially available processed foods were measured by HPLC and the proposed spectrometry method. The levels obtained by the two methods were highly correlated (r 2 > 0.97) for both preservatives. [ABSTRACT FROM AUTHOR]

Selective separation and sensitive detection of dissolved silicon and boron (DSi and DB) in aqueous solution was achieved by combining an electrodialytic ion isolation device (EID) as a salt remover, an ion-exclusion chromatography (IEC) column, and a corona charged aerosol detector (CCAD) in sequence. DSi and DB were separated by IEC on the H + -form of a cation exchange resin column using pure water eluent. DSi and DB were detected after IEC separation by the CCAD with much greater sensitivity than by conductimetric detection. The five-channel EID, which consisted of anion and cation acceptors, cathode and anode isolators, and a sample channel, removed salt from the sample prior to the IEC-CCAD. DSi and DB were scarcely attracted to the anion accepter in the EID and passed almost quantitatively through the sample channel. Thus, the coupled EID–IEC–CCAD device can isolate DSi and DB from artificial seawater and hot spring water by efficiently removing high concentrations of Cl − and SO 4 2− (e.g., 98% and 80% at 0.10 mol L −1 each, respectively). The detection limits at a signal-to-noise ratio of 3 were 0.52 μmol L −1 for DSi and 7.1 μmol L −1 for DB. The relative standard deviations (RSD, n = 5) of peak areas were 0.12% for DSi and 4.3% for DB. [ABSTRACT FROM AUTHOR]

• An inexpensive solid-phase fluorometry for OTA determination was developed. • A small amount of IgG was immobilized only one side of monolith disc. • Effective cleanup was performed by sample loading from the non-immobilized side. • Its application to agricultural samples demonstrated the analytical performance. We established a method for directly measuring mycotoxin ochratoxin A (OTA) in foods by solid-phase fluorescence of monolith-immobilized antibodies. The antibody was introduced onto only one side of an 8 mm-diameter, 3 mm-thick monolith via covalently immobilized protein G. 4 μg (2.7 × 10−11 mol) of antibody was immobilized per one monolith. A maximum of 10 μg (2.4 × 10−11 mol) OTA adsorbed to the activated side of each monolith. The amount of OTA adsorbed and the fluorescence intensity showed good linearity in the range of 0.5–3 ng OTA. Loading the sample solution onto the non-antibody side on the monolith blocked the hydrophobic fluorescent matrices from reaching the immobilized surface of the antibody. The proposed method was able to detect 1 ng OTA/g in solid samples with complex matrices. Mean recoveries obtained at spiked concentration of 3 ng g−1 OTA/g were 78–90% with relative standard deviations of <7.9%. [ABSTRACT FROM AUTHOR]

• Effects of components in vodkas were investigated on the stimulative taste of ethanol. • Mg salts reduced the alcohol-stimulative taste in EtOH-H 2 O solution. • Mg salts strengthened the hydrogen-bonding structure of water-ethanol. • These two phenomena were not found with other salts, such as K, Na, and Ca. • Some Mg salts from water could improve the quality of vodkas. Quantitative analyses of chemical components and sensory tests were carried out on vodka samples to test for stimulative taste of ethanol. Proton nuclear magnetic resonance (1H NMR) spectra of the vodkas were measured with 600 MHz NMR. The effects of salts on the alcohol-stimulative taste were investigated for 15% (v/v) EtOH-H 2 O solution. 1H NMR spectroscopy results showed that a magnesium salt could reduce the stimulative taste of ethanol organoleptically and, at the same time, strengthen the hydrogen-bonding structure of water-ethanol, although the effect of the magnesium could not be clarified quantitatively in the products of vodka. It was also suggested that a change in the water-ethanol hydrogen-bonding structure could lead to a reduction in the stimulative taste of ethanol in vodka. [ABSTRACT FROM AUTHOR]

• Capillary electrophoresis provides highspeed simultaneous separation. • Salivary anions and cations are analyzed in 5 min in a single injection. • This method provides useful information on changes in ion concentrations in saliva. • Multiple regression analyses are combined to evaluate the salivary ion data. This paper describes the simultaneous capillary electrophoresis (CE) of anions and cations using an anion exchange-modified capillary, which was prepared by chemical coating with a cationic silylating reagent, and its application to saliva analysis. The CE method provides high-throughput (5 min for a single sample injection) analysis by generating a high-velocity electroosmotic flow at pH 3.0–3.5. The detection limits at a signal-to-noise ratio of 3 ranged from 1.2 to 18 μM for anions and 1.0 to 2.7 μM for cations. The relative standard deviations for the migration times and peak areas of analytes (n = 4) ranged from 0.05% to 0.40% and 0.94% to 4.7%, respectively. The CE system was used to analyze 11 common ions in saliva samples collected from long-distance runners and sedentary university students before and after running for a set distance or a set time. Interestingly, the SCN− concentrations decreased in the saliva samples of all 14 athletes and 16 sedentary students after running. Furthermore, when the concentrations of the analyzed ions were compared with that of cortisol as a typical stress marker by multiple regression analysis, SCN− and NO 3 − in saliva samples from the two subject groups strongly correlated with cortisol levels, as determined by an electrochemiluminescence immunoassay. This study improves our knowledge of both the analytical methodology for CE and statistical methods for identifying common ions that could be used as physical stress markers. [ABSTRACT FROM AUTHOR]