The Experts below are selected from a list of 234 Experts worldwide ranked by ideXlab platform
Gregory S. Girolami - One of the best experts on this subject based on the ideXlab platform.
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Microscale vacuum Distillation Apparatus for high-boiling, air- and heat-sensitive liquids.
Talanta, 2020Co-Authors: Sumeng Liu, Gregory S. GirolamiAbstract:We describe a simple Apparatus that enables the vacuum Distillation of ~0.2 mL of air- and water-sensitive, high-boiling liquids. The Apparatus should be useful in teaching laboratories, and also to practicing chemists.
Sheng Yen Hsu - One of the best experts on this subject based on the ideXlab platform.
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Multifunctional microchip-based Distillation Apparatus II - Aerated Distillation for sulfur dioxide detection.
Analytica chimica acta, 2019Co-Authors: Loise Ann N. Dayao, Sheng Yen Hsu, Chan Chiung Liu, Lemmuel L. TayoAbstract:Abstract A multifunctional microchip-based Distillation Apparatus is presented for the distilled of sulfur dioxide (SO2) in food products. The microchip is fabricated on poly(methyl methacrylate) (PMMA) substrates, and comprises a sample zone, a buffer zone, a serpentine Distillation column, and a collection zone. In the process, the sample is introduced into the sample zone and is heated under carefully controlled temperature and time conditions. The resulting SO2 and water vapor are carried by nitrogen (N2) gas to the Distillation column, where the SO2 is separated from the water vapor via the condensing effects of a continuous cold water flow. Finally, the SO2 is transported to the collection zone, where it is collected with hydrogen peroxide (H2O2) and its concentration determined using an alkali-based titration and paper-based detection method. A Distillation efficiency of 90.5% is obtained under the optimal Distillation conditions at concentrations of 20–4000 ppm. Moreover, a linear correlation (R2 = 0.9997) is observed between the experimental measurements of the SO2 concentration and the known concentration. The validity of the presented microchip-based Distillation Apparatus is further investigated by distilling the SO2 concentrations of 25 commodity samples. The detection results show that the deviation does not exceed 5.4% compared with the traditional official method.
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Multifunctional microchip-based Distillation Apparatus I - Steam Distillation for formaldehyde detection
Analytica chimica acta, 2019Co-Authors: Sheng Yen Hsu, Chan Chiung Liu, Chia En YangAbstract:Abstract A multifunctional microchip-based Distillation Apparatus for distilling and detecting formaldehyde (CH2O) in food products is developed. The presented Apparatus comprises a disposable microchip, a steam supply system, and a recirculating cooling water supply. The microchip is formed on PMMA substrates by laser ablation and includes a sample zone, a flash Distillation zone, a cooling zone, a condensation zone, and a collection zone. In the presented method, the CH2O sample is placed in the microchip and is vaporized by the high-throughput vapor supply and driven through the condensed zone. The condensed CH2O liquid is guided into the collection zone of the microchip. Finally, the distilled CH2O solution is determined using an AHMT spectrometry method and a paper-based RGB (red, green and blue) intensity analysis method. A distilled efficiency is as high as 98%, when a vapor stream rate is 0.4 ml/min and a distilled time is 10 min. Moreover, both detection methods show linear relationships of the corresponding CH2O concentrations. The actual sample suitability of the presented multifunctional microchip-based Distillation Apparatus is confirmed by analyzing the CH2O concentrations of 21 commodities.
John Tsaknis - One of the best experts on this subject based on the ideXlab platform.
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Determination of malondialdehyde in traditional fish products by HPLC
The Analyst, 1999Co-Authors: John Tsaknis, Stavros Lalas, Evangelos EvmorfopoulosAbstract:The oxidation state of traditional fish products was measured by determining the malondialdehyde (MDA) level by HPLC and the results were compared to those given by a spectrophotometric method. The procedure involves oxidation of the products by incubation at 40 degrees C for 3 d. Samples were steam distilled in a Kjeldahl Distillation Apparatus and the MDA was determined in the aqueous distillates by HPLC, using a micro-Bondapak C18 column, with mixed mobile phase of 1% acetic acid-acetonitrile (85 + 15; v/v). A total time of 2 min was necessary to assay each distillate and only MDA was detected. MDA can be determined at a level of 1.5 x 10(-8) mol l-1. The highest rate of oxidation of the samples, as shown by the changes in the TBA test and MDA concentration determined by HPLC, was observed in smoked fish and the lowest in dried-salted fish.
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Rapid high-performance liquid chromatographic method of determining malondialdehyde for evaluation of rancidity in edible oils
The Analyst, 1998Co-Authors: John Tsaknis, Stavros Lalas, Vassiliki Tychopoulos, Michael Hole, Gillian SmithAbstract:A simple HPLC method for the determination of malondialdehyde (MDA) in oxidised vegetable oils was developed and the results were compared with those given by a spectrophotometric method. Vegetable oil was steam-distilled in a Kjeldahl Distillation Apparatus and the MDA was determined in the aqueous distillates by HPLC, using a µ-Bondapak C18 column, with a mobile phase of 1% acetic acid–acetonitrile (85 + 15, v/v). A total time of 2 min was necessary to assay each distillate and only MDA was detected. MDA can be determined at a level of 1.5 × 10–9 mol l–1.
Lemmuel L. Tayo - One of the best experts on this subject based on the ideXlab platform.
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Multifunctional microchip-based Distillation Apparatus II - Aerated Distillation for sulfur dioxide detection.
Analytica chimica acta, 2019Co-Authors: Loise Ann N. Dayao, Sheng Yen Hsu, Chan Chiung Liu, Lemmuel L. TayoAbstract:Abstract A multifunctional microchip-based Distillation Apparatus is presented for the distilled of sulfur dioxide (SO2) in food products. The microchip is fabricated on poly(methyl methacrylate) (PMMA) substrates, and comprises a sample zone, a buffer zone, a serpentine Distillation column, and a collection zone. In the process, the sample is introduced into the sample zone and is heated under carefully controlled temperature and time conditions. The resulting SO2 and water vapor are carried by nitrogen (N2) gas to the Distillation column, where the SO2 is separated from the water vapor via the condensing effects of a continuous cold water flow. Finally, the SO2 is transported to the collection zone, where it is collected with hydrogen peroxide (H2O2) and its concentration determined using an alkali-based titration and paper-based detection method. A Distillation efficiency of 90.5% is obtained under the optimal Distillation conditions at concentrations of 20–4000 ppm. Moreover, a linear correlation (R2 = 0.9997) is observed between the experimental measurements of the SO2 concentration and the known concentration. The validity of the presented microchip-based Distillation Apparatus is further investigated by distilling the SO2 concentrations of 25 commodity samples. The detection results show that the deviation does not exceed 5.4% compared with the traditional official method.
Chan Chiung Liu - One of the best experts on this subject based on the ideXlab platform.
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Multifunctional microchip-based Distillation Apparatus II - Aerated Distillation for sulfur dioxide detection.
Analytica chimica acta, 2019Co-Authors: Loise Ann N. Dayao, Sheng Yen Hsu, Chan Chiung Liu, Lemmuel L. TayoAbstract:Abstract A multifunctional microchip-based Distillation Apparatus is presented for the distilled of sulfur dioxide (SO2) in food products. The microchip is fabricated on poly(methyl methacrylate) (PMMA) substrates, and comprises a sample zone, a buffer zone, a serpentine Distillation column, and a collection zone. In the process, the sample is introduced into the sample zone and is heated under carefully controlled temperature and time conditions. The resulting SO2 and water vapor are carried by nitrogen (N2) gas to the Distillation column, where the SO2 is separated from the water vapor via the condensing effects of a continuous cold water flow. Finally, the SO2 is transported to the collection zone, where it is collected with hydrogen peroxide (H2O2) and its concentration determined using an alkali-based titration and paper-based detection method. A Distillation efficiency of 90.5% is obtained under the optimal Distillation conditions at concentrations of 20–4000 ppm. Moreover, a linear correlation (R2 = 0.9997) is observed between the experimental measurements of the SO2 concentration and the known concentration. The validity of the presented microchip-based Distillation Apparatus is further investigated by distilling the SO2 concentrations of 25 commodity samples. The detection results show that the deviation does not exceed 5.4% compared with the traditional official method.
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Multifunctional microchip-based Distillation Apparatus I - Steam Distillation for formaldehyde detection
Analytica chimica acta, 2019Co-Authors: Sheng Yen Hsu, Chan Chiung Liu, Chia En YangAbstract:Abstract A multifunctional microchip-based Distillation Apparatus for distilling and detecting formaldehyde (CH2O) in food products is developed. The presented Apparatus comprises a disposable microchip, a steam supply system, and a recirculating cooling water supply. The microchip is formed on PMMA substrates by laser ablation and includes a sample zone, a flash Distillation zone, a cooling zone, a condensation zone, and a collection zone. In the presented method, the CH2O sample is placed in the microchip and is vaporized by the high-throughput vapor supply and driven through the condensed zone. The condensed CH2O liquid is guided into the collection zone of the microchip. Finally, the distilled CH2O solution is determined using an AHMT spectrometry method and a paper-based RGB (red, green and blue) intensity analysis method. A distilled efficiency is as high as 98%, when a vapor stream rate is 0.4 ml/min and a distilled time is 10 min. Moreover, both detection methods show linear relationships of the corresponding CH2O concentrations. The actual sample suitability of the presented multifunctional microchip-based Distillation Apparatus is confirmed by analyzing the CH2O concentrations of 21 commodities.