Reported positive ion fragmentation of phenolic acid derivatives in rice (Oryza sativa L.) were summarized based on the literature. A total of eight phenolic acids (4 derivatives of ferulic acid, 3 derivatives of sinapic acid and p-coumaric acid) were isolated and identified from rice (raw and steamed) using UPLC-DAD-QToF/MS. Results revealed that 6-O-feruloylsurose was the major component with 3'-O-sinapoylsucorse being tentatively identified in Oryza sativa L. for the first time as a new hydroxycinnamoyl derivative in rice grains. In our study, raw brown rice had the highest phenolic acid contents with Samkwang showing higher phenolic acid content than Saeilmi and Sindongjin (12.41 vs. 7.89 and 3.10 mg/100 g dry weight, respectively). Of all varieties, brown rice had higher phenolic acid contents than white rice. These contents decreased considerably when rice was steamed whereas, p-coumaric acid and ferulic acid contents were increased. Additionally, contents of rice (raw and steamed) can be used as a fundamental report for new rice varieties.

Chelating agents in low and intermediate radioactive wastes can form complexes with radionuclides and increase the mobility of the radionuclides. According to the Korea Radioactive Waste Agency (Acceptance criteria for low and intermediate radioactive waste, WAC-SIL-2022-1), if the amount of residual chelating agents in the waste are greater than 0.1%, the chemical names and residual amounts should be specified; if greater than 1%, the waste must be solidified and contain no more than 8%. The existing method for analyzing chelates in radioactive waste was based on UV–Visible spectrophotometry (UV-Vis), but the new method is based on liquid chromatography/mass spectrometry (LC-MS). The analysis was performed in aqueous solution before applying to real samples. Since the real sample may contain several heavy metals, it is expected that the chelates will exist as complexes. Therefore, 1.0×10-4 mol L-1 of EDTA (Ethylenediaminetetraacetic acid), DTPA (Diethylenetriaminepentaacetic acid), NTA (Nitrilotriacetic acid), and excess metals in aqueous solution were analyzed using HPLC using RP (Reverse Phase) column and HILIC (Hydrophilic interaction) column. When the RP column was used, each substance eluted without separation at the beginning of the analysis. However, when analyzed using a HILIC column, the peaks of each substance were separated. LC-MS measurements using HILIC conditions resulted in separations with better sensitivity.

Some consumer goods containing radioactive substances are in circulation and used in everyday life. In accordance with the Nuclear Safety Act, consumer goods with radioactivity are regulated. However, since most consumer goods distributed in Korea have no information that can confirm the amount of radiation, it is necessary to analyze the radiation for safety regulation. Among these consumer goods, GTLS (Gaseous Tritium Light Source) contains gaseous tritium (tritium, written as 3H or T), which is a radioactive material. The gaseous composition ratio in GTLS was analyzed using a precision gas mass spectrometer (Thermo Fisher, model MAT 271). As a result of GTLS analysis, the H2, HD or H3 +(T) or 3He, HT or D2 or He, DT, and T2, which correspond to the mass-to-charge ratio (m/z) 2 to 6 and the air components were detected. In addition, substances corresponding to m/z=24 and m/z=21 were also detected. These were compared with pure CH4 and those fragmentation patterns. The ratios of CT4 (m/z = 24) to CT3 (m/z = 21) and CH4 (m/z = 16) to CH3 (m/z = 15) were compared and they agree within the measurement uncertainty. We also performed additional experiments to separate the water component in the GTLS samples, considering the possibility that the m/z = 21 to m/z = 24 region is tritium compounds based on H2O. Despite the removal of the water components, peaks were detected at m/z=21 and m/z=24. Therefore, we confirmed that the component of m/z = 24 in the GTLS sample was CT4.

To analyze the activity concentration of radionuclides in radioactive sludge samples generated from low- and intermediate-low-level radioactive waste from domestic nuclear power plant, a pretreatment process that dissolves and homogenizes the sample is essential. However, this pretreatment process requires the use of hydrofluoric acid, which makes analysis difficult and challenges users to handle harmful chemicals. Therefore, we aim to minimize the use of hydrofluoric acid by measuring gamma nuclides in the sludge sample without pretreatment process and compare the differences of measurement results according to the sample matrix with and without pretreatment process. We will collect about 0.1 g of the sludge sample, and dissolve it using an acid treatment process after using microwave decomposition. We will then use gamma spectroscopy to check the concentration of nuclides present in the sludge before and after dissolution and consider the effect of the sample matrix.

In gamma-ray spectrometry for volume samples, the self-attenuation effect should be considered in the case of differences in chemical composition and density between the efficiency calibration source for quantitative analysis of sample and the sample actually measured. In particular, the lower the gamma-ray energy, the greater the gamma-ray attenuation due to the self-attenuation effect of the sample. So, the attenuation effect of low-energy gamma-rays in the sample should be corrected to avoid over- or under-estimation of its radioactivity. One of the most important factors in correcting the self-attenuation effect of the sample is the linear attenuation coefficient for the sample, which can be directly calculated using a collimator. The larger the size of the collimator, the more advantageous it is to calculate the linear attenuation coefficient of the sample, but excessive size may limit the use of the collimator in a typical environmental laboratory due to its heavy weight. Therefore, it is necessary to optimize the collimator size and structure according to the measurement environment and purpose. This study is to optimize a collimator that can determine the effective linear attenuation coefficient of low-energy gamma-rays, and verify its applicability. The overall structure of the designed collimator was optimized for gamma-ray energy of less than 100 keV and cylindrical plastic bottle with diameter of 60 mm and a height of 40 mm. The materials of optimized collimator consisted of tungsten. Acryl and acetal were used to form the housing of the collimator, which fixes the central axis of the bottle, collimator and point-like source. In addition, using the housing, the height of the tungsten is adjusted according to the height of the sample. For applicability evaluation of the optimized collimator, IAEA reference material in solid form were used. The sample was filled in the bottle with heights of 1, 2, 3 and 4 cm respectively. Using the collimator and point-like source of 210Pb (46.5 keV), 241Am (59.5 keV), and 57Co (121.1 keV), the linear attenuation coefficient and the radioactivity for the samples were calculated. As a result, to calculate the linear attenuation coefficient using the optimized collimator, a relatively high sample height is required. However, the optimized collimator can be used to determine the linear attenuation coefficients of low-energy gamma-rays for the self-attenuation correction regardless of the sample height. It is concluded that the optimized collimator can be useful to correct the sample selfattenuation effect.

210Po is a naturally occurring radionuclide of 238U decay series with a half-life of 138.4 days. 210Po is decay products of 222Rn, which escapes into the atmosphere and present in all environments with aerosol particles. Also, 210Po has high radiotoxicity and emits a high alpha energy of 5.305 MeV, and it decays to finally become a stable isotope, 206Pb. Therefore, 210Po entering the body by continuously ingestion or inhalation is likely to cause severe damage to the bone marrow, kidney and spleen and other sites in the body. Accordingly, the World Health Organization (WHO) recommends that screening level of gross alpha for drinking water not exceed 0.5 Bq·L−1. Alpha spectrometry has been mainly used for analysis of 210Po, and for the accurate measurement of alpha particle with short range, it is essential to prepare suitable source for alpha detection. The 210Po alpha source is made by a spontaneous deposition method in which polonium is adsorbed thin and flat onto a metal disc, such as silver, nickel and copper. There are various pretreatment methods to separate and concentrate polonium from water samples prior to spontaneous deposition, including Fe(OH)3 or MnO2 co-precipitation and evaporation. However, in the case of co-precipitation, sample contamination or loss of polonium may occur through the experimental processes, and evaporation lead to not only time-consuming process but also may cause loss of polonium due to the low boiling point of polonium. Therefore, in order to compensate for these problems, an efficient polonium analysis method that directly collects polonium from the original sample without a pretreatment is required. In this study, 210Po in bottled drinking water sold in Korea was analyzed using alpha spectrometry. A high purity silver disc (99.99%) was inserted into a newly designed polonium deposition kit to quickly and conveniently collect polonium from a water sample. The polonium alpha detecting source was made effectively only by the spontaneous deposition method without a complicated pretreatment. The source was measured using a PIPS detector, and the radioactivity concentration of 210Po was calculated using 209Po as a yield tracer.

The objective of this study was to develop a simultaneous method for 8 amino acids including alanine, arginine, glutathione, lysine, ornithine, methionine, threonine and tryptophan in veterinary products using LC-MS/MS. To optimize MS analytical condition of 8 amino acids, each parameter was established by multiple reaction monitoring in positive mode. The chromatogram separation was achieved on a C18 column with mobile phase of 0.1% formic acid in D.W. and 0.1% formic acid in acetonitrile for green technology at a flow rate of 0.4mL/min for 5 min with gradient elution. The developed method was validated for mass accuracy, precision, linearity in veterinary products. Calibration curves were linear over the calibration ranges (0.5 – 10 mg/L) for all the analytes r2>0.99. Average recoveries were 92.96 – 105.61% and relative standard deviations (RSD) were 0.27 – 3.5%. The limit of detection (LOD) and the limit of quantification (LOQ) were 0.04 – 0.83 mg/L and 0.12 – 2.52 mg/L, respectively. All values were corresponded with the criteria ranges requested by CD 2002/657/EC. The application of this method will be helpful in quality control analysis of amino acids in veterinary products.

최근 선박용 연료유에 대한 황 함유량 규제를 준수하기 위해 저유황유의 수요가 증가하고 있다. 그러나 저유황유를 공급하는 시기, 지역, 회사 별로 그 품질이 상이함에 따라 선내 연료유 저장탱크에서는 과도한 슬러지가 발생하는 등 혼합 안정성에 대한 문제가 제기되고 있다. 따라서 본 연구는 초음파의 캐비테이션 현상을 이용하여 저유황유의 품질 향상을 하고자 하였다. 선내 저장 탱크에서 이종의 연료유가 혼합되는 상황을 모사하기 위해 두 가지 종류의 저유황유(황 함유량 0.5 % 이하 MGO, MDO)를 혼합하여 시료유로 사용하였다. 원료유와 50 wt.% 씩 혼합한 시료유를 120분 동안 초음파 처리하였으며, 40분 주기로 채취된 샘플은 GC/MS 분석을 수행하여 초음파 조사 시간에 따른 시료유의 조성 변화를 분석하였다. 연구결과, 초음파의 캐비테이션 효과로 인하여 화학결합이 깨지면서 MGO 내 존재하는 고분자량 화합물의 감소와 저분자량의 화합물 증가가 관찰되었다. MDO와 혼합유의 경우, 초음파 조사 후 저분자 화합물에 대한 상대 존재 비의 부분적 증가가 관찰되었지만 시간과 상대 존재비 사이의 상관관계는 관찰되지 않았다.

안전한 화장품용 방부제에 대한 연구를 위하여 1, 2-octanediol (OD)에 galactose 한 분자가 결합된 1, 2-octanediol galactoside (OD-gal)의 합성을 시도하였다. 이를 위하여, 재조합 대장균의 β-galactosidase (β-gal)를 이용하여 transgalactosylation 반응을 수행하였으며, OD-gal 합성을 확인하기 위하여 mass spectrometry 분석과 NMR (1H- and 13C-) spectroscopy 분석을 실시하였다. 합성 반응물에서 m/z=331.1732의 sodium adduct ion 형태로 OD-gal 분자의 합성을 확인하였고, 정제된 OD-gal의 NMR 분석을 통하여 OD-gal의 1H NMR 스펙트럼에서 OD에 갈락토실화가 되었음을 보여주는 다양한 피크를 확인하였다. 1H NMR 스펙트럼의 다운필드인 δH 4.39 ppm과 δH 3.98~3.55 ppm에서 나타나는 다양한 피크들은 이들이 OD에 갈락토실화가 되었다는 것을 잘 암시하고 있으며, 또한 1H NMR 스펙트럼의 업필드에서 나타나는 δH 1.52~1.26 ppm과 0.89 ppm의 피크는 OD의 CH2 와 CH3 작용기로 부터 나타나는 피크로써 OD가 본 물질에 존재함을 알 수 있었다. 13C NMR 스펙트럼에서는 OD-gal의 알파-아노머와 베타-아노머의 구조에서 기인하는 총 24개의 탄소피크가 나타났고, 각 아노머 마다 14개의 탄소가 존재하는데 이중 δc 31.4, 29.0, 22.3 그리고 13.7 ppm에 보이는 OD 4개의 탄소는 지방족 사슬의 끝부분에 해당하며 화학적 구조의 유사성으로 인하여 탄소 피크가 겹쳐서 나타난 것으로 보인다. 따라서 총 28개의 탄소 피크 중 24개가 나타났다. 마지막으로, 합성된 OD-gal 의 β-gal을 이용한 가수분해 반응을 통하여 OD-gal에 gal이 결합되어 있다는 것을 확인하였다. 이러한 결과를 바탕으로 세포독성이 감소된 첨가물 개발을 기대하고 있으며, 추가적인 후속연구를 진행할 예정이다.

PURPOSES : The purpose of this study is to evaluate the asphalt binder properties using FTIR analysis. METHODS : To investigate the chemical properties of asphalt binders, FTIR tests were performed. Recently, FTIR was used for quantification under various aging conditions. Three scans were averaged for each sample within the wavenumber range of 4000 to 400 cm-1, at a resolution of 4 cm-1 (default Simatech software settings). To determine the oxidation of the extracted asphalt binder and the remaining TCE solution in the extracted asphalt binder, the penetration test was adopted and compared. To track the changes in the chemical composition of the aged bitumens, the ATR spectrum of each sample was analyzed, both qualitatively and quantitatively. The qualitative analysis involved identifying characteristic absorption peaks for the functional group of interest, such as polymer components, carbon and sulfur oxidation products, and polar aromatics. RESULTS : The asphalt binder is easily oxidized in air during FTIR testing. To reduce the oxidization of the asphalt binder, the asphalt binder must avoid air contact to measure constant results. Sometimes, the extracted asphalt binder has a residual solvent (TCE), which affects the evaluation of the extracted asphalt binder rheology, such as absolute viscosity and penetration testing. To solve this problem, the research team adopted the FTIR test method. First, the TCE was scanned with FTIR to obtain the chemical characteristics of TCE. After that, the extracted asphalt binder was scanned and the FTIR spectra were compared with those of TCE. If there is a TCE in the extracted asphalt binder, a typical peak was found in the spectrum. Thus, it is possible to estimate the content of the TCE remaining in the extracted asphalt binder via the FTIR test method. CONCLUSIONS : It is possible to evaluate the aging of asphalt binder through FTIR analysis used for the analysis of the chemical structure of asphalt. In addition, during FTIR analysis, the sample is required to avoid air contact to obtain accurate results. FTIR analysis was conducted to confirm whether the solvent (TCE) remained in the extracted asphalt binder and it was confirmed that the penetration increased by a factor of two when the solvent remained. This suggests that it is difficult to control the quality of the asphalt mixture by controlling the amount of recycled additive, as well as the aging of the extracted asphalt binder.

2019년 1월부터 11월까지 서울약령시장에서 유통되는 식·약 공용 농산물 총 187건을 대상으로 곰팡이독소 동시 다성분 SPE 컬럼으로 정제 후 LC-MS/MS로 분석하여 곰팡이독소 8종의 동시분석법 유효성을 검증하고, 확립된 분석법으로 곰팡이독소 오염도 파악 및 위해평가를 실시하였다. LC-MS/MS를 이용한 동시분석법의 유효성 검증은 매질효과, 직선성, 검출한계, 정량한계, 정확성 및 정밀성으로 하였다. 매질 보정 검량선의 상관계수(r2)는 0.9999이상의 우수한 직선성을 보였고, 검출한계는 0.02-0.11 μg/ kg였고, 정량한계는 0.06-0.26 μg/kg였고, 회수율은 81.2- 118.7%였고, 상대표준편차는 0.33-8.90%로 우수한 재현성을 나타냈다. 확립된 분석법으로 검사한 결과 기준이 설정된 아플라톡신은 B1이 1.18-7.29 μg/kg (기준: 총 아플라톡신 15.0 μg/kg이하, B1 10.0 μg/kg이하)으로 기준 이내로 검출되었고, 아플라톡신 B2, G1 및 G2는 검출되지 않았다. 기준이 미설정된 곰팡이독소는 푸모니신(0.84-14.25 μg/ kg) 오크라톡신 A (0.76-17.42 μg/kg) 및 제랄레논(1.73- 15.96 μg/kg)이 검출되었다. 위해평가 결과 아플라톡신 B1의 1일 인체노출량은 0.00052 μg/kg b.w./day였고, 푸모니신 및 제랄레논의 일일섭취한계량 대비 각각 0.04%, 0.24% 였고, 오크라톡신 A의 주간섭취한계량 대비 4.76%로 우리나라 국민들이 식·약 공용 농산물 섭취로 인한 곰팡이 독소 위해도는 안전한 것으로 평가되었다.

In this study, chemical information on a total of 20 individual compounds was constructed to identify isoflavones from the previous reports related with used parts(seeds, leaves, stems, pods) and products of soybean(Glycine max L.). Through constructed library and UPLC-DAD-QToF/MS analysis, a total of 19 individual isoflavones including aglycones, glucosides, acetylglucosides and malonylglucosides as major compounds was identified and quantified from 14 selected soybean seeds. Among them, genistein 7-O-(2"-O-apiosyl)glucoside and genistein 7-O-(6"-O-apiosyl)glucoside(ambocin) were identified tentatively as novel compounds in soybean seeds. Besides, among malonylglucosides, glycitein 4'-O-(6''-O-malonyl)glucoside was estimated for the first time. Total isoflavone contents were distributed from 240.21 to 445.21(mg/100 g, dry matter) and 7-O-6''-O-malonylglucosides were composed of 77.8% on total isoflavone as well as genistein derivatives were confirmed as major class. It was considered importantly that the development of isoflavone-rich varieties was necessary to strengthen their effects such as anti-inflammation, anti-cancer and menopause mitigation. The qualitative and quantitative data presented precisely in this study could be help to select and breed isoflavone-rich varieties. Furthermore, their basic isoflavone profile is expected to be applied to estimate the change of isoflavone conjugates on bioavailability after soy food supplements.

This study investigated the residue of tulathromycin (TLM) on the lung tissue of pigs intramuscularly injected with 2.5 mg/kg body weight as a single dose. Nine healthy cross swine were intramuscularly injected with the drug. Three treated animals were arbitrarily selected to be sacrificed at 7, 10 and 14 days after treatment. TLM residue concentrations in lung tissue were determined using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). The drug was extracted from lung samples using acetonitrile followed by clean-up with n-hexane. The analyte was separated on a Hypersil GOLDTM liquid chromatography column using 0.1% formic acid in deionized distilled water and acetonitrile. The correlation coefficient (R2) of the calibration curve was 0.9981, and the limits of detection and quantification were 10 and 50 μg/kg, respectively. Recoveries at three spiking levels ranged between 95.0-98.2%, and relative standard deviations were less than 3.95%. In TLM-treated group, the concentration of TLM on 7, 10 and 14 days post-treatment was 627.3, 496.9, 259.1 μg/kg, respectively. The developed method is sensitive and reliable for detection of TLM in porcine lung tissues. In addition, it can detect below the maximum residue limits in animal-derived food products destined for human consumption.

본 연구는 불법적으로 식품에 사용될 수 있는 부정물질 11종에 대한 안전관리 강화를 위해 정량 및 정성 분석이 가능한 HPLC-DAD와 LC-MS/MS를 검증하기 위해 수행 되었다. 확립된 시험법은 AOAC 가이드라인에 따라 직선성, 정밀성, 정량한계 및 회수율 등을 통해 유효성을 확인 하였다. 본 실험에서 정량한계를 포함하여 검량선을 작성 하였고, 모두 0.99 이상의 직선성을 확인하였다. 또한 정확성은 LC (90.0-106%), LC-MS/MS (83.0-114%) 이고, 정 밀도는10% 이하로 재현성이 우수하였다. 확립된 시험법은 식품 중 부정물질 안전관리 및 모니터링에 활용될 것으로 사료된다.