• Transactions of the Korean hydrogen and new energy society
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• v.21 no.6
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• pp.561-569
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• 2010

The present study deals with experimental investigations on the syngas-oxygen combustion characteristics of a swirl-stabilized premixed flame in a 10 kW combustor. The effect of hydrogen in syngas has been investigated with different swirl angles to identify the role of hydrogen and swirl strength on the flame stability and CO emissions. The results show that hydrogen addition extended the blowout limit while narrowing the flashback limit. The dependence of blowout on the swirl angle is negligible while the dependence of flashback on the swirl angle is evidenced by two regimes depending on the amount of hydrogen. CO emission is decreased with increasing excess $O_2$ supply or increasing hydrogen content. Chemiluminescence diagnostics is utilized to provide information on the structure of a swirl-stabilized premixed flame. The OH chemiluminescence intensity is more concentrated near the burner exit with an increase in the hydrogen content, which results from high reactivity of hydrogen.

• Journal of Photoscience
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• v.12 no.3
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• pp.149-153
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• 2005

A chemiluminescence (CL) method for the determination of ascorbic acid was proposed, which is based on the enhancement of the CL intensity of $Ru(bipy)_3^{2+}$ - Ce (IV) system with the addition of ascorbic acid. The CL intensity is proportional to the concentration of ascorbic acid in the range of $1{\times}10^{-10}\;to\;1{\times}10^{-5}M$ with a correlation coefficient of 0.9985. The detection limit is $3{\times}10^{-11}M$. The relative standard deviation (R.S.D.) of 10 determinations of 0.1 mM ascorbic acid was 1.75%. The proposed method has been successfully applied to the determination of ascorbic acid in the commercia] drinks. The possible mechanism of the CL reaction was studied.

• 한국연소학회:학술대회논문집
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• 2003.12a
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• pp.75-81
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• 2003

In this paper, the study of effects of flow variables on flame structure and NOx emission concentration was performed in co-axial laminar partially premixed methane/air flames. the objectives are to reveal its effect as parameters were varied and to understand the correlation between flame structure and NOx emission characteristics in the reaction zone. equivalence ratio(${\Phi}$), fuel split degree(${\sigma}$), and mixing distance(x/D) were defined as a premixing degree and varied within $1.36{\sim}3.17$(equivalence ratio), $50{\sim}100$(fuel split degree), and $5{\sim}20$(mixing distance). the image of $OH{\ast}$ and $CH{\ast}$, and NOx concentration were obtained with an ICCD camera and a NOx analyzer. additionally the maximum intensity location of $OH{\ast}$ chemiluminescence and $CH{\ast}$ chemiluminescence were measured to compare each flame structures. In conclusion flame structure and NOx emission characteristics were changed from diffused to premixed flame when mixing degree was on the increase. the main effect on flame structure and NOx production was at first equivalence ratio(${\Phi}$), and next fuel split degree(${\sigma}$), and finally mixing distance(x/D).

• Journal of Microbiology and Biotechnology
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• v.15 no.2
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• pp.310-320
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• 2005

A membrane-based oligonucleotide array was used to detect predominant bacterial species in human fecal samples. Digoxygenin-labeled 16S rDNA probes were generated by PCR from DNA that had been extracted from fecal samples or slurries. These probes were hybridized to an array of 120 oligonucleotides with sequences specific for 40 different bacterial species commonly found in human feces, followed by color development using an alkaline phosphatase-conjugated antibody and NBT /BCIP. Twenty of the species were detected by this method, but E. coli, which was present at $\~$1 $\times 10$^5$ CFU per gram feces, was not detected. To improve the sensitivity of this assay, reverse transcriptase-PCR was used to generate probes from RNA extracted from fecal cultures. Coupled with a chemiluminescence detection method, this approach lowered the detection limit for E. coli from $\~1$ $\times 10$^6$ to ${\leq}$ 1 $\times 10$^5$ These results indicate that the membrane-array method with reverse transcriptase-PCR and chemiluminescence detection can simultaneously identify bacterial species present in fecal samples at cell concentrations as low as${\leq}$ 1 $\times 10$^5$ CFU per gram.

• Bulletin of the Korean Chemical Society
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• v.33 no.1
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• pp.204-208
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• 2012

A novel chemiluminescence (CL) flow injection method for the determination of balofloxacin is described. The method is based on the weak CL signal arising from the reaction of $KBrO_3$ with $Na_2S_2O_4$ in acidic medium being significantly enhanced by balofloxacin in the presence of europium (III) ion and sodium dodecyl benzene sulfonate (SDBS). The experimental conditions that affected CL intensity were carefully optimized and the CL reaction mechanism was briefly discussed. Under the optimum conditions, the relative CL intensity was proportional to the concentration of balofloxacin in the range of $7.0{\times}10^{-11}$ to $3.0{\times}10^{-7}g\;mL^{-1}$. The detection limit was $2.7{\times}10^{-11}g\;mL^{-1}$ and the relative standard deviation was 2.1% for $7.0{\times}10^{-10}g\;mL^{-1}$ balofloxacin (n = 13). The proposed method was successfully applied to the determination of balofloxacin in pharmaceutical formulations and biological fluids.

• Bulletin of the Korean Chemical Society
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• v.30 no.1
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• pp.102-106
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• 2009

A rapid and sensitive chemiluminescence (CL) method using flow-injection (FI) has been developed for the determination of mandelic acid which is based on the enhancement of mandelic acid to the CL intensity of ${Ru(bipy)_{3}}^{2+}$-Ce(IV) system. The enhancement effect was dependent on the concentration of mandelic acid, based on which, CL system was established for the determination of mandelic acid. The concentrations of ${Ru(bipy)_{3}}^{2+}$+, Ce(IV), and $H_2SO_4$ were optimized. Under the optimum experimental conditions, the linear range and detection limit are 1.46-342.0 ${\mu}g/ml$ and 0.072 ${\mu}g/ml$, respectively. The correlation coefficient (R) was 0.99732. The utility of this method was demonstrated by determining mandelic acid in capsules and human urine sample.

• Proceedings of the Korean Society of Food Hygiene and Safety Conference
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• 2002.05a
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• pp.138-138
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• 2002

Oxidative stress has been associated with a number of diseases in human. Among the sources that can generate oxidative stress, it has been reported that iron can generate reactive oxygen species (ROS)with thiol. In iron overload state, increased thiol levels in plasma appeared to be associated with human mortality. In this study we examined whether iron could interact with thiols in plasma, generating ROS. In human plasma, unlike with Fe(III), Fe(II) increased lucigenin-enhanced chemiluminescence in concentration-dependent manner, and this was inhibited by SOD. Boiling of plasma did not affect chemiluminescence induced by Fe(II). Hovever, thiol depletion in plasma by pretreatment with N-ethylmaleimide (NEM)decreased Fe(II)-induced chemiluminescence significantly, suggesting that Fe(II) generated superoxide anion by the nonenzymatic reaction with plasma thiol. Consistent with this findings, albumin, the major thiol contributor in plasma, also generated ROS with Fe(II) and this generation was inhibited by pretreatment with NEM. Treatment with Fe(II) to plasma resulted un significant reduction of oxygen radical absorbance capacity (ORAC) value, suggest that total antioxidant capacity could diminished in iron overload state. In conclusion, In iron overload state, plasma may be affected by oxidative stress mediated by nonenzymatic reaction of Fe (II)with plasma thiol.

• Analytical Science and Technology
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• v.19 no.3
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• pp.218-225
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• 2006

A molecularly imprinted polymer (MIP) was synthesized by radiation-induced polymerization (RIP), where the ferulic acid was used as a template molecule, 4-vinylpyridine as a monomer and ethylene glycoldimethacrylate (EGDMA) as a cross-linking monomer. The MIP was packed in a glass column using a slurry method for use in medium pressure liquid chromatography (MPLC). The MPLC column was tested for separation and purification of ferulic acid from the rice oil. When repeated three times, the MPLC separation/purification yielded the ferulic acid with the purity higher than ~99%. The chemiluminescence of the luminal (5-amino-2,3-dihydro-1,4-phtalazinedione) measured on a potato disc slide (5.0 mm thick) was enhanced in the presence of ferulic acid, while, without the ferulic acid, the chemiluminescence of luminol on the potato slice disc was not observed, which suggests the ferulic acid obtained from the rice oil can be useful for immunoassay.

• Applied Chemistry
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• v.15 no.1
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• pp.21-24
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• 2011

A sensitive silver nanoparticles (Ag NPs) enhanced chemiluminescence (CL) method is reported for the determination of mandelic acid (MA). This method is based on the luminol-KIO₄ system catalyzed by Ag NPs to produce CL spectra. Prepared Ag NPs were characterized by UV-visible spectra and TEM image. Under optimal condition, CL spectra of the system were responded linearly with the concentration of MA in the range of 2.5×10^-9 to 2.0×10^-8 mol L^-1 (r=0.9989) with a detection limit of 1.2×10^-10 mol L^-1. The relative standard deviation of 1.0×10^-7 mol L^-1 MA was found 1.45 (n=9).

• Analytical Science and Technology
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• v.31 no.1
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• pp.47-56
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• 2018

Finding the blood left at a crime scene is very important to reconstruct or solve a criminal case. Although numerous reagents have been developed for use at crime scenes, luminol is the most representative. Bluestar Forensic has been used in recent years, but is expensive and cannot be stored after preparation. This study aims to develop a new luminol reagent that can be stored for a long period of time while maintaining the chemiluminescence intensity at the level of Bluestar Forensic. Because luminol dissolves well in aqueous alkaline solutions, the use of sodium hydroxide in the preparation of luminol reagents can promote the decomposition of hydrogen peroxide. Magnesium sulfate, sodium silicate, and potassium triphosphate have been used as hydrogen peroxide stabilizers. The effects of the addition of these substances on the chemiluminescence emission intensity and the storage period of the luminol reagents were confirmed. The addition of a hydrogen peroxide stabilizer was shown to have no significant affect on the chemiluminescence emissions intensity or stabilized pH of the luminol reagent during storage. It also greatly increases the shelf life of the reagents. The use of magnesium sulfate as a hydrogen peroxide stabilizer is the most appropriate. When sodium perborate is used instead of hydrogen peroxide as an oxidizing agent, there is no significant change in the sensitivity and chemiluminescence emissions intensity, but the storage period is shortened. However, after the reaction with blood, the pH of the mixed solution does not increase significantly, and is judged to be more suitable than a reagent made of hydrogen peroxide.