• Journal of the Optical Society of Korea
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• v.7 no.4
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• pp.240-244
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• 2003

Simultaneous determination of concentrations for four major components in human blood serum was investigated using a Fourier-transform mid-infrared spectroscopy. Infrared spectra of human blood serum were measured in 8.404 ∼ 10.25 ${\mu}m$ range where the highest absorption peaks of glucose are located. A partial least square (PLS) algorithm was utilized to establish a calibration model for determining total protein, albumin, globulin and glucose levels which are commonly measured metabolites. The standard error of cross validation obtained from our multivariate calibration model was 0.24 g/dL for total protein, 0.15 g/dL for albumin, 0.17 g/dL for globulin, and 6.68 mg/dL for glucose, which are comparable with or meet the criteria for clinical use. The results indicate that the infrared absorption spectroscopy can be used to predict the concentrations of clinically important metabolites without going through a chemical process with a reagent.

• Proceedings of the IEEK Conference
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• 2002.07a
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• pp.269-272
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• 2002

This work describes the use of neural networks (NNs) for interpreting voltammetric data, i.e., current-voltage spectra that obtained from the electrochemical reaction of analyte species at a gold electrode. Current-voltage spectra of glucose, fructose and ascorbic acid in mixtures obtained from dual-pulse staircase voltammetry (DPSV) was in the form of the mixed responses contain characteristics of the individual analytes approximately in proportion to their concentration. Extraction of individual analyte concentration from combined data was subsequently achieved using NNs. The combination of DPSV and NNs opens a possibility for simultaneous determination of mixtures of the species for fruit juices quality monitoring.

• The Korean Journal of Physiology
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• v.15 no.2
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• pp.97-101
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• 1981

The early plasma gastrin responses to single oral glucose or casein solution were studied in the same normal subjects on different days. After an overnight fast, glucose or casein solution was ingested within few minutes at the breakfast time. The plasma gastrin responses to these solutions were compared and contrasted with the concentration when the subjects received glucose solution intravenously. Results were as follows: 1) Rapid intravenous glucose infusion did not produce any changes in the plasma gastrin concentration. 2) Plasma gastrin concentration rose and peaked within 10 minutes after an oral liquid ingestion and then decreased substantially by 15 minutes, but remained slightly above fasting levels at 60 minutes. 3) There was no significant difference between the mean plasma gastrin concentrations after glucose of casein ingestion, but each fluid produced a significant increase in serum gastrin above fasting levels. 4) The subjects who produced high plasma gastrin response to glucose solution did so to casein solution. Conversely a low response to one solution reflected a low response to the other solution. 5) From the above results, authors discussed that individual responsibility rather than the sorts of meals is the factor in the determination of the magnitude of the early gastrin response.

• Korean Journal of Food Science and Technology
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• v.45 no.5
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• pp.537-544
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• 2013

This study was performed to establish method of simultaneous determination of fructose, glucose, and sucrose in honey and commercial vitamin drinks by GC and GC/MS. Optimum chromatographic separation of trimethylsilyl-oxime (TMSO) derivatives by GC was achieved on a DB-5 column. Calibration curves for fructose, glucose and sucrose TMSO derivatives by GC were linear in the range of 50-5000 ${\mu}g/mL$, and their $r^2$ values were 0.9999, The limit of detection and limit of quantification of fructose, glucose, and sucrose were 0.68, 0.47, and 0.53 ${\mu}g/mL$, respectively, and 2.27, 1.58, and 1.77 ${\mu}g/mL$, respectively. Average recoveries of fructose, glucose, and sucrose were 100.5, 101.0, and 99.7%, respectively. When the method was applied to 12 honey samples, the average concentrations of fructose, glucose and sucrose were $42.58{\pm}1.97%$, $27.74{\pm}1.16%$, and $0.79{\pm}0.52%$, respectively. The F/G ratio was $1.53{\pm}0.07$. For fructose and glucose contents, results from the GC analysis were similar to those from the HPLC analysis, but the sucrose content was different for each analysis method. We suggest that the GC method is more suitable than other official analytical methods for simultaneous determination of fructose, glucose, and sucrose in honey.

• Journal of the Korean Chemical Society
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• v.59 no.1
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• pp.88-92
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• 2015

• Microbiology and Biotechnology Letters
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• v.19 no.3
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• pp.296-302
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• 1991

Glucose isomerase producer, which produces 488 U/ml of glucose isomerase activity in 500 ml flask scale, was isolated among 666 isolates of Actinomycetes from pine forest soil samples. The isolate was identified as Streptomyces luteogriseus through the studies about morphology (spiral aerial mycelia), cell wall type (Type I), spore chains (spiral form), pigment formation (gray melanine pigment) & metabolism (sugar utilization etc). The optimum conditions of fermentation were determined in 500 ml flask scale. The enzyme production was reached maximum after 4 days at pH 6.0~8.0 and 27~$30^{\circ}C$ in the medium containing 1.5~3.0% of xylose; 0.5-0.8% of glucose; 0.1% of $MgSO_4.7H_20$; 0.05% of $CoCI_2-6H_20$; 7.5% of corn steep liquor.

• Applied Biological Chemistry
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• v.27 no.3
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• pp.158-162
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• 1984

In order to estimate the basic data for the processing suitability of fruits, the contents of free sugars in citrus fruits(14 varieties) cultured in Jeju island, and peaches(4), grapes(4), pears(3) and apples(6) obtained from a local market were investigated by HPLC. The sucrose was the most abundant sugar in citrus fruits and peaches, and followed by fructose and glucose in order. The sugar contents in citru fruits was a wide difference according to the variety. In citrus fruit, the sucrose content was about 53 to 65% to total free sugars and the ratio of fructose to glucose was 1.0/0.8-1.1. The sugars present in grapes and pears were fructose of most abundance, glucose and sucrose in order. Jangshiprang pear showed 2 times higher fructose content than other variety. The free sugar in Taeyang and Hongok(Jonathan) apples were fructose, glucose and sucrose in order of abundance which fructose, sucrose and glucose in Golden Fuji and Mutsu.

• Analytical Science and Technology
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• v.5 no.2
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• pp.177-184
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• 1992

A preparation method and response characteristics of a glucose sensor which consisted of pH-ISFET and glucose oxidase-immobilized membrane were investigated. The pH-ISFET glucose sensor was fabricated by immbilizing bovine serum albumin and glucose oxidase with glutaraldehyde on gate of the pH-ISFET. Effects of pH and concentration of working buffer and enzyme load on the pontentiometric response of the pH-ISFET glucose sensor were examined. Response characteristics for the determination of glucose in synthetic physiological saline solution(pH 7.4) were as follows. That is the concentration range of linear response, slope of linear response(sensitivity), and response time were $1.0{\times}10^{-4}{\sim}6.0{\times}10^{-3}M $, 4.1 mV/decade, and 12~15 min., respectively.

• Journal of the Korean Chemical Society
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• v.43 no.3
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• pp.264-270
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• 1999

Enzyme electrodes for amperometric measurement of glucose were prepared by immobilization of glucose oxidase on an Immobilon-AV Affinity membrane and attachement to a Pt electrodes. The electrochemical oxidation of Hz02 was monitored at +0.8V vs. Ag/AgCl. Response was linear from 0.2 mM to 20mM. The detection limit was 10m3 mM. Response time, the optimum pH and life time of enzyme immobilized membrane was 12 seconds, pH 5.5(CH3COONaJCH3COOH) and about 27 days, respectively. When the enzyme electrode was applied for the determinaion of glucose with amperometric method, other physiolosical materials have not interfered. Also, we compared the result with that from AOAC(Association of Offical Analytical Chemists) method, measuring the glucose in sweet potato. The relative error was 0.1%.

• Journal of Electrochemical Science and Technology
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• v.14 no.3
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• pp.252-261
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• 2023

Glucose detection is particularly important for clinical diagnosis and personal prevention and control. Herein, the smartphone-based amperometric glucose sensors were constructed using the NiS/CuS nanorods (NRs) as sensing electrodes. The NiS/CuS NRs were prepared through a facile hydrothermal process accompanied by the subsequent vulcanization treatment. The morphological and structural properties of NiS/CuS NRs were characterized with SEM, EDS, XRD, and XPS. Electrochemical measurements including cyclic voltammetry, chronoamperometry, and electrochemical impedance spectroscopy display that NiS/CuS NRs can act as highly efficient electrocatalyst for glucose detection. The NiS/CuS NRs electrodes present a wide detection range of 1-8000 µM for glucose sensing with the sensitivity of 956.38 µA·mM^-1·cm^-2. The detection limit was 0.35 µM (S/N=3). When employed in smartphone-based glucose sensing device, they also display a high sensitivity of 738.09 µA·mM^-1·cm^-2 and low detection limit of 1.67 µM. Moreover, the smartphone-based glucose sensing device also presents favorable feasibility in determination of glucose in serum samples with the recoveries ranging between 99.5 and 105.8%. The results may provide a promising viewpoint to design other new portable glucose sensors.