Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 96
Filter
1.
J Chromatogr A ; 1720: 464769, 2024 Apr 12.
Article in English | MEDLINE | ID: mdl-38442499

ABSTRACT

In this study, we introduce a novel approach for the analysis of salivary ions using capillary electrophoresis (CE) with a triple-layer coated capillary. The capillary is sequentially coated with cationic silylating reagents, poly(vinylsulfonate), and polybrene to form a custom designed surface that effectively inhibits adsorption of protein matrix on the capillary inner wall and allows for reproducible ion analysis. For the CE with capacitively coupled contactless conductivity detection, we used suitable background electrolytes (BGEs) for salivary ion analysis. Anions were separated using a mixture of 2-(N-morpholino)ethanesulfonic acid and l-arginine, and cations were separated using that with 18-crown-6. This setup enabled rapid separation, within 4 min, together with sensitive detection. We quantified nine common anions and five cations typically found in saliva samples using this CE method, both before and after a cold pressure test (CPT, a standard stress test). The CE system demonstrated consistent ion separation across 30 consecutive measurements without requiring capillary replacement. Notably, the salivary ion balance remained predominantly anion-rich, regardless of the CPT. Cold water exposure induced greater variation in the total anion concentration than in the total cation concentration. Further analysis using multiple regression analysis revealed strong relationships between nitrate and nitrite, formate and phosphate, and potassium and nitrate, before and after the CPT. Notably, potassium and nitrate ions exhibited variations in response to stress. These results provided a method for assessing salivary ion composition and insights into the potential of salivary ions as biomarkers for stress.


Subject(s)
Electrophoresis, Capillary , Nitrates , Cations/analysis , Anions/analysis , Electrophoresis, Capillary/methods , Water , Potassium
2.
Anal Sci ; 39(5): 739-748, 2023 May.
Article in English | MEDLINE | ID: mdl-36943656

ABSTRACT

Mercury (Hg) is harmful to the human body. Its physical properties and toxicity differ greatly depending on its chemical form. The quantification of soluble Hg in soils or sediments is crucial for preventing further environmental contamination by Hg sources such as products, processes, and storage. In this study, the risk of leachable Hg that release from soil to the hydrosphere was evaluated by the sequential extraction procedure (SEP), a speciation method of a targeted element based on the solubility of its various compounds. The SEP, which consists of a four-channel circulating flow system (FCFS), was developed to reduce the time and amount of liquid required for SEP of leachable Hg in the Bloom method, which is a conventional SEP for Hg in a solid sample. The SEP with FCFS was optimized by considering the impact of extractant volume, circulation extraction time, and flushing of the extraction line. In the three-step (Fraction 1-3) sequential extraction of leachable Hg in soil samples, the optimized SEP with FCFS required 45 mL of extractant and 2.5 h, while the common batch SEP required 75 mL of extractant and 49 h. Furthermore, the combination of the SEP with FCFS for the leachable forms (Fraction 1-3) and the batch method for the insoluble forms (Fraction 4-5) was applied to the five-step SEP of Hg from CRM-JSAC0403. The sum of Hg concentrations that were classified into five fractions was in good agreement with that obtained from the batch method for all extraction, indicating that there are no significant differences in the concentrations extracted from the four channels.

3.
Kyobu Geka ; 76(2): 165-167, 2023 Feb.
Article in Japanese | MEDLINE | ID: mdl-36731855

ABSTRACT

A 81-year-old woman was referred to our hospital for neck discomfort. Chest computed tomography (CT) showed a tumor in the upper mediastinum. Fluorodeoxyglucose-positron emission tomography (FDG-PET) showed the mild accumulation in the tumor. Percutaneous biopsy was performed and epithelioid hemangioendothelioma was suspected, and the surgical treatment was performed. The histological study showed polygonal and irregular cells with nuclear atypia in myxoma-like substrate compatible with epithelioid hemangioendothelioma.


Subject(s)
Hemangioendothelioma, Epithelioid , Mediastinum , Female , Humans , Aged, 80 and over , Fluorodeoxyglucose F18 , Hemangioendothelioma, Epithelioid/diagnostic imaging , Hemangioendothelioma, Epithelioid/surgery , Hemangioendothelioma, Epithelioid/pathology , Positron-Emission Tomography , Tomography, X-Ray Computed
4.
Anal Sci ; 39(5): 671-677, 2023 May.
Article in English | MEDLINE | ID: mdl-36637706

ABSTRACT

Radioactive isotope (RI) metals are a new type of tracer for positron emission tomography generated from the target metal by proton irradiation using a cyclotron. The generated metal RIs need to be separated from the target metal rapidly and effectively. In the present study, we developed a 3D-printed flow device to separate metal RIs from target metals. The separation was performed with selective formation of ethylenediaminetetraacetic acid (EDTA) complex based on the difference in formation constants. The RI metal selectively formed a EDTA complex, thus changing its ionic charge in solution. The solution was then introduced into a cation exchange column for selective adsorption of the target metal. The solution with added chelator and controlled pH was introduced into the developed system and automatically separated metal RI from target metals within 14 min. The separation method was applied to separate RI 67Ga from target metal Zn using a mixture of 107 pg L-1 67Ga in 250 mg L-1 Zn2+. The recoveries of 67Ga and Zn were 97% and 100%, respectively. Furthermore, an ultraviolet (UV) radiation reactor was integrated into the system to decompose the EDTA complex and recover the Ga3+ ion. Ga3+ recovery by UV radiation was effective, 87%. The developed system was also successfully applied to the separation of Zr and Y. Therefore, the method and system can be applied to separate other metal RIs from target metals.

5.
Kyobu Geka ; 75(12): 1059-1061, 2022 Nov.
Article in Japanese | MEDLINE | ID: mdl-36299163

ABSTRACT

A 67-year-old woman was referred to our hospital for cough and fever. Chest computed tomography (CT) showed some masses showing slightly enhanced effect in the pericardium. FDG-PET showed the accumulation of FDG in the masses. Thoracoscopic surgical biopsy was performed to establish the diagnosis. The histological study showed proliferation of short spindle-shaped cells surrounded by lymphocyte, and the spindle cells were immunohistochemically positive for cytokeratin AE1/AE3, WT-1, D2-40, CAM5.2, intelectin-1 and negative for CEA, TTF-1, napsin A, claudin-4, calretinin, MUC4, PAX8, CD30. These findings were compatible with epithelial pericardial malignant mesothelioma.


Subject(s)
Heart Neoplasms , Lung Neoplasms , Mediastinal Neoplasms , Mesothelioma, Malignant , Mesothelioma , Thymus Neoplasms , Female , Humans , Aged , Mesothelioma/diagnostic imaging , Mesothelioma/surgery , Calbindin 2 , Fluorodeoxyglucose F18 , Lung Neoplasms/pathology , Claudin-4 , Keratins
6.
ACS Omega ; 7(18): 15779-15785, 2022 May 10.
Article in English | MEDLINE | ID: mdl-35571765

ABSTRACT

Preparing compounds containing the radioisotope 64Cu for use in positron emission tomography cancer diagnostics is an ongoing area of research. In this study, a highly efficient separation method to recover 64Cu generated by irradiating the target 64Ni with a proton beam was developed by employing a flow electrolysis cell (FE). This system consists of (1) applying a reduction potential for the selective adsorption of 64Cu from the target solution when dissolved in HCl and (2) recovering the 64Cu deposited onto the carbon working electrode by desorbing it from the FE during elution with 10 mmol/L HNO3, which applies an oxidation potential. The 64Cu was selectively eluted at approximately 30 min under a flow rate of 0.5 mL/min from the injection to recovery. The newly developed flow electrolysis system can separate the femtomolar level of ultratrace radioisotopes from the larger amount of target metals as an alternative to conventional column chromatography.

7.
Anal Sci ; 38(3): 563-569, 2022 Mar.
Article in English | MEDLINE | ID: mdl-35286633

ABSTRACT

A zirconia (ZrO2) stationary phase with a chemically fixed silane coupling agent (trimethyl [3-(trimethoxysilyl)propyl]ammonium chloride; TMA), which possesses quaternary ammonium functional groups, is evaluated as a separation column for ion chromatography (IC) of anions. The selectivity for anions varies depending on the amount of TMA immobilized on the ZrO2. The TMA-ZrO2, with an anion-exchange capacity of 17 ± 3 µeq/g, shows an anion-exchange reaction that involves the specific retention of fluoride ion on ZrO2. The TMA-ZrO2 exhibits a decrease of the anion resolution with an increase of the eluent pH and an enhancement of the selective separation of fluoride ion with an increase of the column temperature. Through this study, the TMA-ZrO2 stationary phase shows potential as a new medium for ion separation.


Subject(s)
Zirconium , Anions , Chromatography, Ion Exchange/methods , Indicators and Reagents , Zirconium/chemistry
8.
Anal Sci ; 38(1): 207-214, 2022 01.
Article in English | MEDLINE | ID: mdl-35287224

ABSTRACT

Radiocesium concentrations were measured in the pectoralis muscles of great cormorant (n = 36) collected from Gunma Prefecture between November 2011 and July 2012. The 137Cs contamination levels in great cormorant were consistent with the 137Cs deposition levels on ground soil and 137Cs concentrations in freshwater fishes. The Tag of great cormorants were comparable with those of other birds except for copper pheasant.


Subject(s)
Fukushima Nuclear Accident , Radiation Monitoring , Animals , Birds , Nuclear Power Plants , Soil
9.
Anal Methods ; 14(9): 957-961, 2022 03 03.
Article in English | MEDLINE | ID: mdl-35136894

ABSTRACT

This technical note illustrates the possibility of using a conductivity cell electrode (CCE) as an ion chromatography (IC) detector to extend the application fields of this analytical technique. A conventional non-suppressed IC system consists of an eluent delivery pump, a separation column, column oven, and conductivity detector (CD). In this study, the conventional CD, which is one of the expensive parts of the instrument, is replaced with a relatively inexpensive CCE, leading to comparable peak resolution, detection sensitivity, and relative standard deviation. The separation effectiveness was retained and the developed IC-CCE system was successfully applied to the simultaneous separation of inorganic anions (SO42-, Cl-, and NO3-) and cations (Na+, NH4+, K+, Mg2+, and Ca2+) in three natural mineral water samples, with good accordance between the monitored values obtained using the CCE and CD. The commercially available CCE is potentially suitable for application as an IC detector for monitoring ionic components with overall IC cost reduction.


Subject(s)
Chromatography, Ion Exchange , Anions/analysis , Cations/analysis , Chromatography, Ion Exchange/methods , Electric Conductivity , Electrodes
10.
Anal Chem ; 93(51): 17069-17075, 2021 12 28.
Article in English | MEDLINE | ID: mdl-34910462

ABSTRACT

Short-lived radioactive metals are important tracers in clinical diagnosis. Radioactive metals for clinical use are produced from suitable target metals in cyclotrons. The trace amount of radioactive metal produced is contained in a relatively large amount of target metal. A rapid and effective method is required to isolate the radioactive metal. In the present study, selective complex formation followed by cation-exchange adsorption was performed in a continuous flow-based system. Ethylenediamine-N,N,N',N'-tetraacetic acid (EDTA) was selected as the ligand after simulation of the separation of radioactive Ga from the target (Zn). Selectively, the Ga-EDTA complex passed through the cation trap, while Zn2+ was trapped. This separation principle is opposite to that of typical solid-phase extraction, which captures the target ion. The proposed separation was performed in a flow-based system with a parallel, open-channel ion trap. The performance was optimized by altering the channel dimensions, channel-filling mesh, and flow rate. Finally, the target radioactive metal, Ga, was selectively and effectively (>99%) separated from a mixture of 50 fg Ga/L and 100 mg Zn/L. The concentration of Zn remaining in the Ga solution was 2.3 µg/L. The complexed Ga was converted to free Ga3+ by a simple UV irradiation method. The proposed method effectively and rapidly separates trace amounts of radioactive metals contained in larger amounts of target metals using a simple flow system that can be operated on site.


Subject(s)
Cyclotrons , Metals , Indicators and Reagents , Solid Phase Extraction
11.
Anal Methods ; 13(9): 1106-1109, 2021 03 07.
Article in English | MEDLINE | ID: mdl-33569554

ABSTRACT

A simple method for determining total inorganic mercury (Hg) in solution using an enclosed quartz cell applying cold vapour-atomic absorption spectrometry (CV-AAS) can reduce sample volume, reductant, and cost compared with those of official methods. The Hg determination under the optimised conditions achieves precision similar to that of conventional CV-AAS.

12.
Anal Sci ; 37(1): 93-105, 2021 Jan 10.
Article in English | MEDLINE | ID: mdl-33071268

ABSTRACT

Ion-exclusion chromatography (IEC) is categorized as a type of ion chromatography and is recognized as a simple and convenient water quality monitoring technology for a variety of ionic and nonionic substances. This review, mainly focusing on historical milestone studies by various authors, outlines the archives that concern the separation sciences and practical applications obtained from a variety of IEC modes used for water-quality monitoring as follows: (1) early-developed IEC; (2) IEC using enhanced conductivity detection for weak ionic substance; (3) IEC using nonionic substances eluents such as sugars or polyols; (4) vacancy IEC based on a novel separation concept; (5) applications to the water quality monitoring of inorganic ionic-nutrients; (6) simultaneous IEC and cation-exchange chromatography of anions and cations; and (7) the multicomponent IEC combining different separation modes and detection methods with the expansion of applicable fields, such as for food analysis or material evaluations.

13.
RSC Adv ; 11(31): 18702-18707, 2021 May 24.
Article in English | MEDLINE | ID: mdl-35478608

ABSTRACT

Methods for effectively utilizing lignin are necessary for the realization of a sustainable society. Herein, we report a method for directly converting lignin to graphene-based materials. Fe-supported lignin is prepared by dissolving lignin in an aqueous FeCl2 solution, followed by freeze drying. Graphene is then produced by catalytically carbonizing this Fe-supported lignin at 1200 °C. The characteristics of both the Fe catalyst and lignin are crucial for the production of high-quality graphene. Specifically, the lignin should disperse well in water, freeze dry, and carbonize via solid-state carbonization. The obtained graphene-based material is highly resistant to electrochemical oxidation, as observed in other graphene-based materials. The direct conversion of lignin to graphene described herein is an unprecedented method for synthesizing large amounts of graphene-based material at low cost, as well as being an excellent use for lignin.

14.
J Chromatogr A ; 1635: 461647, 2021 Jan 04.
Article in English | MEDLINE | ID: mdl-33291035

ABSTRACT

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 NO3- 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.


Subject(s)
Anions/isolation & purification , Cations/isolation & purification , Electrophoresis, Capillary/methods , Saliva/chemistry , Biomarkers/analysis , Electroosmosis , Humans , Indicators and Reagents , Limit of Detection
15.
Anal Chem ; 92(22): 14953-14958, 2020 11 17.
Article in English | MEDLINE | ID: mdl-32959650

ABSTRACT

Radioactive metals are applied in biochemistry, medical diagnosis such as positron emission tomography (PET), and cancer therapy. However, the activity of radioisotopes exponentially decreases with time; therefore, rapid and reliable probe preparation methods are strongly recommended. In the present study, electrodialytic radioactive metal ion handling is studied for counter ion conversion and in-line probe synthesis. Presently, counter ion conversion and probe synthesis are achieved by evaporative dryness and solution mixing, respectively. Evaporative dryness is time-consuming and is a possible process that can lead to loss of radioactive metal ions. Mixing of solutions for synthesis makes dilution and undesirable effects of counter ion on the synthesis. An optimized electrodialytic flow device can transfer a radioisotope, 64Cu2+, with high recovery from HCl matrices to HNO3 (∼100%). Matrices can also be transferred into acetic acid and citric acid, even though the concentration of the metal ion is at the picomolar level. The ion transfer can also be achieved with simultaneous counter ion conversion, complex synthesis, and enrichment. When the ligand was dissolved in an acceptor solution, the transferred metal ions from the donor were well mixed and formed a complex with the ligand in-line. The efficiency of the synthesis was ∼100% for 1.0 pM 64Cu. A relatively larger donor-to-acceptor flow rate can enrich the metal ion in the acceptor solution continuously. The flow rate ratio of 10 (donor/acceptor) can achieve 10 times enrichment. The present electrodialytic ion handling method can treat ultra-trace radioisotopes in a closed system. With this method, rapid, effective, and safe radioisotope treatments were achieved.


Subject(s)
Electrochemical Techniques/instrumentation , Metals/chemistry , Radioisotopes/chemistry , Hydrochloric Acid/chemistry , Indicators and Reagents/chemistry
16.
Kyobu Geka ; 73(7): 553-556, 2020 Jul.
Article in Japanese | MEDLINE | ID: mdl-32641677

ABSTRACT

A 71-year-old woman was referred to our hospital for a round mass shadow in the right lower lung field in mass screening chest X-ray. Computed tomography (CT) of the chest showed a well-defined lobulating mass shadow measuring 2.2 cm in diameter in the lower lobe of the right lung and a ground glass opacity ( GGO) in the upper lobe of the left lung. She underwent video-assisted partial resection of right lower lobe of the lung. The pathological examinations indicated a pulmonary metastasis of follicular thyroid carcinoma. Three months later, video-assisted partial resection of left upper lobe of the lung was performed. Microscopically, 2 lesions of adenocarcinoma in situ were revealed.


Subject(s)
Adenocarcinoma, Follicular , Lung Neoplasms , Thyroid Neoplasms , Aged , Female , Humans , Lung , Tomography, X-Ray Computed
17.
Anal Sci ; 36(5): 531-535, 2020 May 10.
Article in English | MEDLINE | ID: mdl-32173674

ABSTRACT

We monitored the relationship between the cadmium (Cd) concentration uptake of rice and the oxidation-reduction potential (ORP) at the soil surface with the supplementation of fermented botanical waste-based amendment (FBWA), an organic fertilizer prepared from woody and food wastes. This study was carried out for 3 years in the western part of Jiangsu Province, China. It was found that the Cd concentration taken up by rice was correlated to a decreased the ORP of the cultivated soil. The yield of rice was ∼1.20 times higher than that of the control plot. The effects of reducing the Cd content in rice and increasing the rice yield remained for 2 years after FBWA application. Finally, Cd was immobilized in the soil with adsorption to FBWA or the decomposed products. The ORP measurement during rice cultivation might be a key index to predict the suppression effect of Cd uptake into the rice or limitation of the sustainable effect by the FBWA.


Subject(s)
Cadmium/analysis , Fermentation , Food Contamination/analysis , Oryza/chemistry , Soil Pollutants/analysis , Cadmium/metabolism , China , Dietary Supplements , Farms , Food Analysis , Oryza/metabolism , Oxidation-Reduction , Soil/chemistry , Soil Pollutants/metabolism , Surface Properties
18.
Anal Sci ; 36(5): 611-615, 2020 May 10.
Article in English | MEDLINE | ID: mdl-32037349

ABSTRACT

Recovery of copper was attempted from municipal waste incineration ashes using acid extraction and electrodeposition by a flow-through type electrolysis cell (FE). Efficient extraction of copper from the incineration ash was obtained using 0.5 mol L-1 sulfuric acid, i.e., copper extraction rate: 78% from bottom ash and 88% from fly ash. The copper in the 10-fold diluted extractant injected into the FE was quantitatively adsorbed by applying -0.4 V and was quantitatively desorbed by eluting with nitric acid.

19.
Anal Sci ; 35(10): 1117-1122, 2019 Oct 10.
Article in English | MEDLINE | ID: mdl-31231089

ABSTRACT

This study demonstrated that a guard column containing anion-exchange resin has the potential for use as a separation column for acid eluent. Specifically, a 1-cm long anion-exchange guard column with a 4.6-mm internal diameter provided good separation of monovalent inorganic anions, by elution of 8 mM tartaric acid or 4 mM malic acid. Using the guard column with acid eluent could be applied to evaluation of nitrite and nitrate ions in mountain and urban river water samples. When the guard column was connected in front of a cation-exchange separation column (15 cm long × 4.6 mm internal diameter) in a series, the system provided simultaneous separation of anions and cations in eluent of 8 mM tartaric acid and 0.5 mM 18-crown-6 ether by a single injection.

20.
Anal Sci ; 35(10): 1089-1096, 2019 Oct 10.
Article in English | MEDLINE | ID: mdl-31204369

ABSTRACT

A method for extracting metals from solid samples was developed. The system had four flow channels (each containing a column packed with a solid sample), a single-flow peristaltic pump, and eight six-port valves. An extractant was passed into each channel for a specified period, then the valves were closed. We evaluated the system by performing a four-step sequential extraction procedure to extract heavy metals from a lake sediment sample. The four extractants were, in order of use, magnesium chloride, ammonium acetate, hydroxylamine hydrochloride, and hydrochloric acid. The concentrations of the analytes extracted agreed well with the concentrations determined using the batch method. The system was also successfully used to analyze heavy metals in a soil sample from a parking lot and fly ash from a domestic waste disposal facility. The total amount of extractant required per sample using the system was two-thirds of the amount required using the batch method.

SELECTION OF CITATIONS
SEARCH DETAIL
...