• Journal of Food Hygiene and Safety
• /
• v.35 no.3
• /
• pp.252-260
• /
• 2020

This study was conducted to improve the standard method for vitamin B₁₂ and biotin contained in foods for special dietary uses to ensure the specificity of the complex matrix properties of foods. For the food code, the test method was improved to determine vitamin B₁₂ and biotin by high-performance liquid chromatography (HPLC)-UV using column-switching after concentration using immunoaffinity column. The immunoaffinity columns contain a gel suspension of monoclonal antibody specific to the vitamin of interest so that it can be used to concentrate the vitamin B₁₂ and biotin and remove interferences from the food extracts. Moreover, validation of advanced new methods was carried out to support the suitability of the proposed analytical procedure (specificity, linearity, detection limits (LOD), quantitative limits (LOQ), accuracy, and precision). The improved analytical method is being used to monitor relevant food items on sale. The results of this study showed that the new analytical method is suitable and appropriate for managing food intended for special dietary uses.

• Journal of Food Hygiene and Safety
• /
• v.36 no.1
• /
• pp.34-41
• /
• 2021

The purpose of this research is to improve analysis methods of determining the contents of fatty acids in infant formulas and follow-up formulas. A gas chromatography (GC) method was performed on a GC system coupled to flame ionization detector, with a fused silica capillary column (SP2560, 100 m×0.25 mm, 0.20 ㎛). The method was validated using standard reference material (SRM, NIST 1849a). Performance parameters for method validation such as specificity, linearity, limits of detection (LOD) and quantification (LOQ), accuracy and precision were examined. The linearity of standard solution with correlation coefficient was higher than 0.999 in the range of 0.1-5 mg/mL. The LOD and LOQ were 0.01-0.06 mg/mL and 0.03-0.2 mg/mL, respectively. The recovery using standard reference material was confirmed and the precision was found to be between 0.8% and 2.9% relative standard deviation (RSD). Optimized methods were applied in sample analysis to verify the reliability. All the tested products had acceptable contents of fatty acids compared with component specification for nutrition labeling. The result of this research will provide efficient experimental information and strengthen the management of nutrients in infant formula and follow-up formula.

• Journal of Pharmaceutical Investigation
• /
• v.40 no.1
• /
• pp.33-38
• /
• 2010

Sibutramine is a serotonin-norepinephrine reuptake inhibitor indicated for the management of obesity in conjunction with a reduced calorie diet. The oral administration of sibutramine is followed by its dose-related side effects. In this study, sibutramine was formulated into drug in adhesive (DIA) patches in an attempt to overcome these problems. The effects of different formulation variables including pressure-sensitive adhesive (PSA), loading amount of drug, thickness of matrix and enhancer on the skin permeation of the drug were evaluated using excised hairless mouse skin. In the acrylic adhesive with carboxyl functional group, low release of sibutramine was observed due to the strong interaction between carboxyl group of adhesive and amine group of sibutramine. The acrylic adhesive without functional group provided good adhesion force and allowed high drug loading. Changing drug load as well as thickness of the matrix was found to alter permeation rate. $Crovol^{(R)}$ PK40 and $Crovol^{(R)}$ A40, were found to be effective enhancers for sibutramine. The optimized patch contained 20% sibutramine, and 5% $Crovol^{(R)}$ A40 as permeation enhancer, in $80\;{\mu}m$ thick Duro-$Tak^{(R)}$ 87-9301 matrix.

• Elastomers and Composites
• /
• v.54 no.4
• /
• pp.308-312
• /
• 2019

Polyphenylene sulfide (PPS) is a well-known super engineering plastic with a high melting temperature (above 290℃). It is generally insoluble under regular conditions. Therefore, it can be used for replacing metallic materials. Many researchers are looking at the possibility of replacing aluminum in the engine compartment of an automobile. However, studies on PPS are not common as compared to conventional engineering plastics because only a few companies produce super engineering plastics. In this research, the material properties of PPS composites containing two different kinds of glass fibers and produced under different processing temperatures were investigated. The tensile strength of the PPS composites increased as the processing temperature increased. Although glass fibers with similar aspect ratios were compounded under the same processing condition, one of them yielded a higher mechanical strength.

• Journal of Adhesion and Interface
• /
• v.11 no.2
• /
• pp.50-56
• /
• 2010

Polyethyleneterephthalate (PET) film is widely used in various industrial fields such as mobile phone, display pannel, notebook etc. Recently PET film attached on indium tin oxide (ITO) surface has a role of high pencil hardness, high refractive index etc. So we synthesized two types of multi-functional monomer which are epoxy modifed acrylate and unmodified acrylate type using recyclable resource like phloroglucinol, derived from trinitrotoluene. We studied the effect of multi-functional monomer's chemical structure on the various properties such as refractive index, optical transmittance, and pencil hardness. We characterized synthesized multi-functional monomer by qualitative analysis through H NMR. We observed that pencil hardness of 1,3,5-triepoxide benzene and 1,3,5-triacrylate benzene they have the range of 2~3 H at high UV dosage of 300 mW. Refractive index appeared the value of 1.54~1.57. Transmittance of all multi-functional monomers has more than 93%.

• Proceedings of the Microbiological Society of Korea Conference
• /
• 2002.10a
• /
• pp.221.2-221.2
• /
• 2002

• Polymer Science and Technology
• /
• v.17 no.3
• /
• pp.303-311
• /
• 2006

• Proceedings of the Korean Vacuum Society Conference
• /
• 2008.08a
• /
• pp.66-66
• /
• 2008

• Food Science and Industry
• /
• v.48 no.4
• /
• pp.4-10
• /
• 2015

• Bulletin of the Korean Chemical Society
• /
• v.32 no.4
• /
• pp.1321-1326
• /
• 2011

In this work, the effects of different surface functional groups on the elemental mercury adsorption of porous carbons modified by chemical treatments were investigated. The surface properties of the treated carbons were observed by Boehm's titration and X-ray photoelectron spectroscopy (XPS). It was found that the textural properties, including specific surface area and pore structures, slightly decreased after the treatments, while the oxygen content of the ACs was predominantly enhanced. Elemental mercury adsorption behaviors of the acidtreated ACs were found to be four or three times better than those of non-treated ACs or base-treated ACs, respectively. This result indicates that the different compositions of surface functional groups can lead to the high elemental mercury adsorption capacity of the ACs. In case of the acid-treated ACs, the $R_{C=O}/R_{C-O}$ and $R_{COOH}/R_{C-O}$ showed higher values than those of other samples, indicating that there is a considerable relationship between mercury adsorption and surface functional groups on the ACs.