• Journal of Food Hygiene and Safety
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• v.32 no.4
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• pp.284-289
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• 2017

Oxidized polyethylene wax (OPEW) is, one of the food additives, used as a coating agent in citrus fruits and nuts. OPEW is authorized to quantum satis in EU, USA, and is acceptable less than 250 mg/kg in Australia and New Zealand. But OPEW is unauthorized as a food additive in Korea. This study was to establish the analytical method of OPEW and demonstrate the effective application of various food samples. We first conducted to compare the various analytical method including acid value (AV), high temperature gel permeation chromatography (HT-GPC), matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF/MS), gas chromatography flame ionization detector (GC-FID) and fourier transform infrared spectroscopy (FT-IR). This result indicated that FT-IR spectrum of OPEW treated food sample displayed absorption bands for carbonyl group (C=O, $1714cm^{-1}$), ester group (C-O, $1463cm^{-1}$), aliphatic group (C-H, $2916cm^{-1}$). Furthermore, IR spectrum of OPEW treated food sample showed similar tendency with IR spectrum of OPEW standard. Therefore, it is confirmed that analytical method using FT-IR can be detected on analysis of OPEW in food. As a result of monitoring of 111 samples using established analytical method, OPEW was not detected in the food samples.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.7
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• pp.505-514
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• 2009

Aqueous potassium salt of serine was proposed as an alternative $CO_2$ absorbent to monoethanolamine (MEA) and its $CO_2$ absorption characteristics were studied. The experiment has been conducted using screening test equipment with NDIR type gas analyzer and vapor-liquid equilibrium apparatus. $CO_2$ absorption/desorption rate and net amount of $CO_2$ absorbed in cyclic process are the criteria to assess the $CO_2$ absorption characteristics in this study. Effective $CO_2$ loading of potassium salt of serine and MEA are 0.425 and 0.230 respectively. Cyclic capacities are 0.354 and 0.298 for potassium salt of serine and MEA. The absorption rate of the potassium serinate decreased sharply at $CO_2$ loading is 0.1 and were maintained approximately at half of MEA. To enhance the absorption rate of aqueous potassium salt of serine, small quantities of rate promoters, namely piperazine and tetraethylenepentamine were blended, so that rich $CO_2$ loading were increased by 13.7% and 18.7% respectively. The rich $CO_2$ loading of potassium salt of serine was 29.2% and 35.0% higher than those of aqueous sodium and lithium salt of serine, respectively. The absorption rate of potassium salt of valine and isoleucine which have similar molecular structures to serine were lower than that of serine because of the presence of bulky side group. Precipitation phenomena during $CO_2$ absorption were discussed by the aid of literatures.

• Analytical Science and Technology
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• v.22 no.6
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• pp.488-497
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• 2009

In this study, analytical methodology for several organic fatty acids (OFA: propionic acid (PA), butyric acid (BA), isovaleric acid (IA), and valeric acid (VA)) designated as new offensive odorants in Korea (as of year 2010) was investigated along with some odorous VOCs (styrene, toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, butyl acetate, and isobutyl alcohol). For this purpose, working standards (WS) containing all of these 13 compounds were loaded into adsorption tube filled with Tenax TA, and analyzed by gas chromatography (GC) system thermal desorber interfaced with. The analytical sensitivities of organic fatty acids expressed in terms of detection limit (both in absolute mass (ng) and concentration (ppb)) were lower by 1.5-2 times than other compounds (PA: 0.24 ng (0.16 ppb), BA: 0.19 ng (0.11 ppb), IA: 0.15 ng (0.07 ppb), and VA: 0.28 ng (0.13 ppb)). The precision of BA, IA, and VA, if assessed in terms of relative standard error (RSE), maintained above 5%, while the precison of other compounds were below 5%. The reproducibility of analysis improved with the aid of internal standard calibration (PA: $1.1{\pm}0.4%$, BA: $10{\pm}0.46$, IA; $12{\pm}0.3%$, VA: $4{\pm}0.1%$), respectively. The results of this study showed that organic fatty acid can be analyzed using adsorption tube and thermal desorber in a more reliable way to replace alkali absorption method introduced in the odor prevention law of the Korea Ministry of Environment (KMOE).