The Experts below are selected from a list of 183 Experts worldwide ranked by ideXlab platform
Nobuhito Imanaka - One of the best experts on this subject based on the ideXlab platform.
-
total nitrogen oxides gas sensor based on solid electrolytes with refractory oxide based auxiliary electrode
Journal of The Electrochemical Society, 2004Co-Authors: Nobuhito Imanaka, Shinji Tamura, Gin-ya AdachiAbstract:A new type of total nitrogen oxides (NO X ) gas sensor was fabricated by the conjunction of trivalent aluminum cation and divalent oxide anion conducting solid electrolytes with Potassium Nitrite-doped rare earth oxide-based auxiliary electrode. The sensor response was rapid, reproducible, and a continuous response was obtained. The sensor's electromotive force output is equivalent in both NO and NO 2 detection with obeying the Nernst relationship, indicating that a quantitative total NO X (NO plus NO 2 gases) gas detection can be successfully realized.
-
New type of nitrogen oxide sensor with multivalent cation- and anion-conducting solid electrolytes
Sensors and Actuators B-chemical, 2003Co-Authors: Nobuhito Imanaka, Gin-ya AdachiAbstract:A new nitrogen monoxide (NO) gas sensor was fabricated from a combination of trivalent aluminum cation- and divalent oxide anion-conducting solid electrolytes, with Potassium Nitrite-doped gadolinium oxide solid solution serving as the NO sensing auxiliary electrode. The sensor exhibits rapid response, and provides a continuous and reproducible output. The sensor output shows close agreement with the Nernst equation, thereby demonstrating quantitative NO detection.
-
Extraordinary high Potassium ion conducting polycrystalline solids based on gadolinium oxide–Potassium Nitrite solid solution
Electrochemistry Communications, 2003Co-Authors: Young Woon Kim, Atsushi Oda, Nobuhito ImanakaAbstract:Abstract A new type of Potassium ion conducting polycrystalline solid electrolyte was prepared by forming the Gd 2 O 3 –KNO 2 solid solution. Since KNO 2 is dissolved in the Gd 2 O 3 crystal lattice scale, a considerable enhancement in K + ion conductivity was successfully realized. The K + ion conductivity is more than three orders of magnitude higher than that of the well-known K + ion conducting K 2 SO 4 polycrystal solid and the value also exceeds that of K + –β ″ -alumina single crystal, demonstrating the highest ion conductivity among the K + ion conducting solid series.
-
extraordinary high Potassium ion conducting polycrystalline solids based on gadolinium oxide Potassium Nitrite solid solution
Electrochemistry Communications, 2003Co-Authors: Young Woon Kim, Atsushi Oda, Nobuhito ImanakaAbstract:Abstract A new type of Potassium ion conducting polycrystalline solid electrolyte was prepared by forming the Gd 2 O 3 –KNO 2 solid solution. Since KNO 2 is dissolved in the Gd 2 O 3 crystal lattice scale, a considerable enhancement in K + ion conductivity was successfully realized. The K + ion conductivity is more than three orders of magnitude higher than that of the well-known K + ion conducting K 2 SO 4 polycrystal solid and the value also exceeds that of K + –β ″ -alumina single crystal, demonstrating the highest ion conductivity among the K + ion conducting solid series.
-
Solution of Potassium nitrate into gadolinium oxide lattice
physica status solidi (a), 2003Co-Authors: Young Woon Kim, Shinji Tamura, Atsushi Oda, Toshiyuki Masui, Nobuhito ImanakaAbstract:Gadolinium oxide (Gd 2 O 3 )-Potassium nitrate (KNO 3 ) solid solution has been synthesized by a solid-state reaction. The thermal behavior of the solid solutions has been characterized by using X-ray powder diffraction, elemental analysis, thermal gravimetric and differential thermal analysis, Fourier transform infrared and Raman spectroscopy. From these measurements, it has been confirmed that Potassium Nitrite (KNO 2 ) could dissolve into the Gd 2 O 3 lattice with oxidation to Potassium nitrate (KNO 3 ). By the formation of interstitial solid solutions, nitrate anions were stabilized and remained in the Gd 2 O 3 lattice even if they were heated at 873K, which is higher than the melting points of KNO 2 and KNO 3 .
Gin-ya Adachi - One of the best experts on this subject based on the ideXlab platform.
-
total nitrogen oxides gas sensor based on solid electrolytes with refractory oxide based auxiliary electrode
Journal of The Electrochemical Society, 2004Co-Authors: Nobuhito Imanaka, Shinji Tamura, Gin-ya AdachiAbstract:A new type of total nitrogen oxides (NO X ) gas sensor was fabricated by the conjunction of trivalent aluminum cation and divalent oxide anion conducting solid electrolytes with Potassium Nitrite-doped rare earth oxide-based auxiliary electrode. The sensor response was rapid, reproducible, and a continuous response was obtained. The sensor's electromotive force output is equivalent in both NO and NO 2 detection with obeying the Nernst relationship, indicating that a quantitative total NO X (NO plus NO 2 gases) gas detection can be successfully realized.
-
New type of nitrogen oxide sensor with multivalent cation- and anion-conducting solid electrolytes
Sensors and Actuators B-chemical, 2003Co-Authors: Nobuhito Imanaka, Gin-ya AdachiAbstract:A new nitrogen monoxide (NO) gas sensor was fabricated from a combination of trivalent aluminum cation- and divalent oxide anion-conducting solid electrolytes, with Potassium Nitrite-doped gadolinium oxide solid solution serving as the NO sensing auxiliary electrode. The sensor exhibits rapid response, and provides a continuous and reproducible output. The sensor output shows close agreement with the Nernst equation, thereby demonstrating quantitative NO detection.
Susan Luong - One of the best experts on this subject based on the ideXlab platform.
-
Detection and identification of 2‐nitro‐morphine and 2‐nitro‐morphine‐6‐glucuronide in Nitrite adulterated urine specimens containing morphine and its glucuronides
Drug Testing and Analysis, 2013Co-Authors: Susan Luong, Shanlin FuAbstract:In vitro urine adulteration is a well-documented practice adopted by individuals aiming to evade detection of drug use, when required to undergo mandatory sports and workplace drug testing. Potassium Nitrite is an effective urine adulterant due to its oxidizing potential, and has been shown to mask the presence of many drugs of abuse. However, limited research has been conducted to understand its mechanism of action, and to explore the possibility of the drugs undergoing direct oxidation to form stable reaction products. In this study, opiates including morphine, codeine, morphine-3-glucuronide and morphine-6-glucuronide were exposed to Potassium Nitrite in water and urine to mimic the process of Nitrite adulteration. It was found that two stable reaction products were detected by liquid chromatography-mass spectrometry (LC-MS) when morphine and morphine-6-glucuronide were exposed to Nitrite. Isolation and elucidation using spectrometric and spectroscopic techniques revealed that they were 2-nitro-morphine and 2-nitro-morphine-6-glucuronide, respectively. These reaction products were also formed when an authentic morphine-positive urine specimen was fortified with Nitrite. 2-Nitro-morphine was found to be stable enough to undergo the enzymatic hydrolysis procedure and also detectable by gas chromatography-mass spectrometry (GC-MS) after forming a trimethylsilyl derivative. On the contrary, morphine-3-glucuronide did not appear to be chemically manipulated when exposed to Potassium Nitrite in urine. These reaction products are not endogenously produced, are relatively stable and can be monitored with both LC-MS and GC-MS confirmatory techniques. As a result, these findings have revealed the possibility for the use of 2-nitro-morphine and 2-nitro-morphine-6-glucuronide as markers for the indirect monitoring of morphine and morphine-6-glucuronide in urine specimens adulterated with Nitrite. Copyright © 2013 John Wiley & Sons, Ltd.
-
Detection and identification of 2-nitro-morphine and 2-nitro-morphine-6-glucuronide in Nitrite adulterated urine specimens containing morphine and its glucuronides.
Drug testing and analysis, 2013Co-Authors: Susan LuongAbstract:In vitro urine adulteration is a well-documented practice adopted by individuals aiming to evade detection of drug use, when required to undergo mandatory sports and workplace drug testing. Potassium Nitrite is an effective urine adulterant due to its oxidizing potential, and has been shown to mask the presence of many drugs of abuse. However, limited research has been conducted to understand its mechanism of action, and to explore the possibility of the drugs undergoing direct oxidation to form stable reaction products. In this study, opiates including morphine, codeine, morphine-3-glucuronide and morphine-6-glucuronide were exposed to Potassium Nitrite in water and urine to mimic the process of Nitrite adulteration. It was found that two stable reaction products were detected by liquid chromatography-mass spectrometry (LC-MS) when morphine and morphine-6-glucuronide were exposed to Nitrite. Isolation and elucidation using spectrometric and spectroscopic techniques revealed that they were 2-nitro-morphine and 2-nitro-morphine-6-glucuronide, respectively. These reaction products were also formed when an authentic morphine-positive urine specimen was fortified with Nitrite. 2-Nitro-morphine was found to be stable enough to undergo the enzymatic hydrolysis procedure and also detectable by gas chromatography-mass spectrometry (GC-MS) after forming a trimethylsilyl derivative. On the contrary, morphine-3-glucuronide did not appear to be chemically manipulated when exposed to Potassium Nitrite in urine. These reaction products are not endogenously produced, are relatively stable and can be monitored with both LC-MS and GC-MS confirmatory techniques. As a result, these findings have revealed the possibility for the use of 2-nitro-morphine and 2-nitro-morphine-6-glucuronide as markers for the indirect monitoring of morphine and morphine-6-glucuronide in urine specimens adulterated with Nitrite. Copyright © 2013 John Wiley & Sons, Ltd.
-
2-Nitro-6-monoacetylmorphine: potential marker for monitoring the presence of 6-monoacetylmorphine in urine adulterated with Potassium Nitrite.
Analytical and bioanalytical chemistry, 2012Co-Authors: Susan Luong, Ronald Shimmon, James M. HookAbstract:6-Monoacetylmorphine (6-MAM), being a unique metabolite of heroin, is routinely tested in urine samples to monitor heroin use. However, detection of 6-MAM-related opiates such as morphine is known to be affected by in vitro urine adulteration using oxidizing adulterants such as Potassium Nitrite. This study aimed to investigate the fate of 6-MAM after exposure to Nitrite and to identify any formed oxidation products that may potentially be used for monitoring heroin abuse despite Nitrite adulteration. Potassium Nitrite (0.05 M and 0.6 M) was reacted with 6-MAM (5–10,000 ng/mL) in both water and blank urine with pH adjusted to range from 3 to 8. Following reaction at room temperature for varying periods, the reaction mixtures were monitored by both the CEDIA® Heroin Metabolite (6-AM) immunoassay and liquid chromatography-mass spectrometry (LC-MS) methods. Structural elucidation of the isolated oxidation products was based on mass spectrometry and nuclear magnetic resonance spectroscopic evidence. Nitrite, under acidic environment (pH
R.k. Nkum - One of the best experts on this subject based on the ideXlab platform.
-
Resistivity anomaly in Potassium Nitrite
Materials Chemistry and Physics, 1997Co-Authors: R.k. NkumAbstract:Abstract The temperature dependence of the electrical resistivity of Potassium Nitrite has been investigated in the temperature range 293 to 413 K. An anomaly is observed in the resistivity-temperature curve at about 319 K. This temperature agrees well with the transition temperatures of 315 and 320 K reported by others. The activation energy of KNO 2 changes from 0.16 eV below the transition temperature to 0.02 eV above the transition temperature. These values indicate that in the less disordered rhombohedral phase A the electrons are localised by the local electric field of the domains. Therefore, the electrons need more energy to overcome the local field and to take part in the conductivity. In the highly disordered cubic phase B, the local field drops off and less energy is required for the electrons to take part in the conductivity.
Kristien Mortelmans - One of the best experts on this subject based on the ideXlab platform.
-
Bacterial mutagenicity testing of 49 food ingredients gives very few positive results.
Mutation research, 1991Co-Authors: Michael J. Priva, Vincent F. Simmon, Kristien MortelmansAbstract:49 substances permitted for use in food in the United States was tested for mutagenicity in the Ames Salmonella typhimurium assay and in Escherichia coli strain WP2. Four of these substances caused increases in revertant counts in S. typhimurium. Two of these four (papain and pepsin) were found to contain histidine, and therefore the results of the tests on these two substances could not be taken as demonstrating mutagenicity. The other two substances causing increases in revertant counts (hydrogen peroxide and Potassium Nitrite) were mutagenic. The results on one chemical, beta-carotene, were evaluated as inconclusive or questionable. The remaining 44 substances were nonmutagenic in the test systems used. It is concluded that, for those generally physiologically innocuous chemicals tested, there are very few 'false positives' in the bacterial test systems used.