• 한국수산과학회지
• /
• 제54권4호
• /
• pp.404-410
• /
• 2021

Although, mouse bioassay for the monitoring of azaspiracids (AZAs) toxins in shellfish has been used previously, the reported method has low sensitivity and it is time-consuming. Recently, there is an interest in the quantitative analysis of AZAs using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The purpose of this study is to verify the simultaneous analysis of AZAs in shellfish and tunicate in Korea using LC-MS/MS. To validate the method, linearity, limit of detection (LOD), limit of quantification (LOQ), precision, accuracy, and repeatability were determined. All standard compounds were analyzed within 7 min. The correlation coefficients (R²) of the standard solution was higher than 0.9995 (within the range of 0.8-10.0 ㎍/L). The LODs and LOQs of AZAs in shellfish were 0.08-0.16 ㎍/kg and 0.23-0.50 ㎍/kg, respectively. The accuracy and precision of the method for determining AZAs in shellfish were 87.1-93.0% and 1.23-4.91%, respectively. Consequently, the verified LC-MS/MS method is suitable to analyze AZAs in shellfish and tunicates in Korea.

• 생약학회지
• /
• 제49권1호
• /
• pp.76-83
• /
• 2018

A traditional herbal formula, Gyeji-tang has been used to treat the early colds, headache, chills, and fever in Asian countries. In this study, we were performed simultaneous determination of the 14 bioactive marker compounds, gallic acid, spinosin, paeoniflorin, albiflorin, liquiritin apioside, liquiritin, 6'''-feruloylspinosin, liquilitigenin, coumarin, cinnmamic acid, benzoylpaeoniflorin, cinnamaldehyde, glycyrrhizin, and 6-gingerol in Gyeji-tang using an ultra-performance liquid chromatography-electrospray ionization-mass spectrometry (UPLC-ESI-MS/MS). Analytical column was used a Waters Acquity UPLC BEH $C_{18}$ analytical column ($2.1{\times}100mm$, $1.7{\mu}m$) and maintained at $45^{\circ}C$ with a flow rate of 0.3 mL/min. The mobile phase consists of 0.1% (v/v) formic acid in water and acetonitrile with gradient elution. The MS analysis was conducted using multiple reaction monitoring in the positive and negative modes by a Waters ACQUITY TQD LC-MS/MS system. The calibration curves of 14 bioactive marker compounds showed linearity with correlation coefficients ${\geq}0.9798$. The limits of detection and quantification values were in the range of 0.11-6.66 ng/mL and 0.34-19.99 ng/mL, respectively. As a result of the analysis using the established LC-MS/MS method, the amounts of tested 14 compounds in the lyophilized Gyeji-tang sample were detected up to $85.7{\mu}g/g$. These results may be useful for quality assessment of a traditional herbal formulas.

• 분석과학
• /
• 제23권1호
• /
• pp.54-59
• /
• 2010

액체크로마토그래피/질량분석법(LC/MS)을 이용하여 화장품에 들어있는 파라벤류등을 동시 분석하였다. 화장품 시료를 메탄올에 직접 용해시키고 $0.45\;{\mu}m$ 필터로 여과하여 메탄올/물을 이동상으로 하여 Extend $C_{18}$의 비극성 컬럼을 사용하여 기울기 용리 조건에서 12분 안에 분리하여 SIM(selected ion monitoring)방법으로 정량하였다. LC/MS 분석결과 검량선은 $0.05-10\;{\mu}g$/mL 농도범위에서 $r^2$=0.9993의 상관계수를 갖는 좋은 직선성을 나타내었으며, 검출한계는 $0.01\;{\mu}g$/mL 이었다.

• 치위생과학회지
• /
• 제22권4호
• /
• pp.249-255
• /
• 2022

Background: Sexual dimorphism is important for sex determination in the field of forensics. However, sexual dimorphism is commonly assessed using cone beam computed tomography (CBCT) rather than three-dimensional (3D) modeling software; therefore, studies using a more accurate measurement approach are necessary. This study assessed the sexual dimorphism of the MS using a 3D modeling program to obtain information that could contribute to the fields of surgery and forensics. Methods: The CBCT data of 60 patients (age, 20~29 y; 30 males and 30 females) admitted to the Department of Orthodontics at the Dankook University School of Dentistry were provided in Digital Imaging and Communications in Medicine (DICOM) format. The left MS and right MS were modeled based on the DICOM files using the Mimics (version 22; Materialise, Leuven, Belgium) 3D program and converted to stereolithography (STL) files used to measure the width, length, and height of the MS, infraorbital foramen (IOF), right MS, and left MS. The average of three repeated measurements was calculated, and a reliability test was performed to ensure data reliability (Cronbach's α=0.618). A canonical discriminant analysis was performed using a standard approach (left: Box's M=0.096; right: Box's M=0.115). Results: Males had greater values for all parameters (MS width, MS length, MS height, IOF, right MS, left MS) than females. The discriminant analysis identified six independent variables (MS width, MS height, MS length, IOF, right MS, left MS) that could identify sex. The left MS and right MS correctly identified the sex of 81.7% and 71.7% of the patients, respectively, with the left MS having higher accuracy. Conclusion: This study confirmed that, for Korean individuals, the left MS has a better ability to identify sex than the right MS. These results may contribute to sex identification in the fields of surgery and forensics.

• 대한환경공학회지
• /
• 제32권4호
• /
• pp.349-356
• /
• 2010

과염소산이온의 분석을 위해 전기전도도 검출기(CD; conductivity detector)를 연결한 이온크로마토그래피(IC; ion chromatography) 방법이 지금까지 가장 널리 사용되어 왔다. 그러나 이 방법은 시료의 조성에 영향을 받을 수 있고, 정량한계를 낮추는데 한계가 있다. 따라서, 본 연구에서는 미량의 과염소산이온 분석을 위해 이온크로마토그래피 질량분석법(IC-MS/MS; ion chromatography mass spectrometry)을 제시하였다. IC-MS/MS를 이용한 과염소산이온의 분석방법을 적용한 결과 평균회수율 104.4 ${\pm}$ 5.7%, 상대표준편차 1.9 ${\pm}$ 1.3%를 얻었으며, 검출한계(MDL; method detection limit)는 0.0207 ${\pm}$ 0.0099 ${\mu}g/L$를 얻을 수 있었다. IC-MS/MS를 한강수계 지류천과 본류에 적용시킨 결과, 최소 <0.1 ${\mu}g/L$에서 최고 18.30 ${\mu}g/L$ 범위로 나타났다. 서울시 6개 아리수정수센터의 취수원수와 정수에서는 과염소산이온이 0.18~0.34 ${\mu}g/L$의 농도로 존재하는 것으로 나타났다.

• 식물조직배양학회지
• /
• 제27권3호
• /
• pp.197-202
• /
• 2000

조직배양을 이용한 처녀치마 대량증식을 위한 적정배지, 생장조절제 및 농도구명을 위해 본 연구를 수행하였다. Shootb 및 roots분화의 경우 zeatin 3.0 mgι$^{-1}$을 첨가한 MS 배지에서 shoots및 roots 형성률이 각각 20, 30%로서 가장 양호한 것으로 나타났다. 1/2 MS배지의 경우 zeatin 1.0mgι$^{-1}$에서 shoots 형성률이 67 %, B5 배지에 있어서 zeatin 3.0 mgι$^{-1}$ 처리에서 33 %로 가장 양호한 것으로 나타났다. 배지에 따른 식물 생장조절제 처리에 따른 식물체 분화율은 MS 배지에서는 2,4-D 0.5 mgι$^{-1}$, 1/2 MS 배지에서 zeatin 1.0 mgι$^{-1}$ 및 B5 배지에서 reatin 3.0 mgι$^{-1}$에서 자장 가장 많은 100, 193, 280 및 310%의 분화된 식물체를 얻을 수 있었다. 전반적으로 야생화인 처녀치마의 잎 조직으로부터 multiple shoots을 유도하여 대량증식을 위한 목적으로는 B5 배지에 생장조절제인 zeatin 3.0 mgι$^{-1}$을 첨가시키는 것이 가장 효과적인 것으로 나타났다.

• 대한임상검사과학회지
• /
• 제37권1호
• /
• pp.22-26
• /
• 2005

Total homocysteine is now considered a risk factor for cardiovascular diseases. I increased interest has led to a multitude of studies requiring the determination of total homocysteine in conjunction with other factor. There are various methods for measuring total homocysteine, including HPLC, FPIA, GC-MS and LC-MS/MS. The most recent method for measuring total homocysteine uses a deuterium-labelled internal standard and tandem mass spectrometry. This development requires no derivatization and therefore leads to an increase in sample throughput compared to other techniques. We have evaluated the method for homocysteine by the LC-MS/MS method, and the correlation between the FPIA method and the LC-MS/MS method. The standard curve (0, 5, 10, 20, 50, 100 uM) was linear over the range examined (up to 100 uM). The lower limit of quantification (CV < 10 %) was 0.5 uM/L and the lower limit of detection (S/N >3) was 0.1 uM/L. Intra-assay variation and inter-assay variation were both <6 %. The comparision study for homocysteine concentration showed good correlation (r=0.9684) between the FPIA method and LC-MS/MS methods. Our conclusion is that the method showed relatively good precision, and was rapid and accurate.

• 한국가금학회지
• /
• 제33권2호
• /
• pp.127-131
• /
• 2006

본 시험은 expanding 가공 기술이 산란계의 생산성, 계란 품질과 영양소 소화율에 대하여 알아보고자 실시하였다. 49주령 Hy-line Brown 270수를 공시하였고, 6주간 시험을 실시하였다. 1) MS(mash), 2) EC(expanded crumble) 및 3) EP( expanded pellet) 으로 3처리구로 구성하였으며, 처리 당 15반복, 반복당 6수씩 완전임의 배치하였다. 산란율은 EC와 EP 처리구가 MS 처리구와 비교하여 유의적으로 높게 나타났다(p<0.05). 그러나 난중은 처리구간에 유의적인 차이는 없었다(p>0.05). 난각 강도는 EC와 EP 처리구가 MS 처리구와 비교하여 유의적으로 높게 나타내었지만(p<0.05), 난각 두께는 처리 구간에 유의적인 차이를 나타내지 않았다(p>0.05). 난황색은 EC 처리구가 MS 처리구와 비교하여 유의적으로 높게 나타났다(p<0.05). 난황 계수는 EC와 EP 처리구가 MS 처리구와 비교하여 유의적으로 높게 나타났다(p<0.05). Haugh uint에 있어서 처리구간의 유의적인 차이는 없었으나(p>0.05), 변화량에 있어서 EP 처리구가 가장 높게 나타났다(p<0.05). 영양소 소화율에 있어서 건물, 칼슘, 인 소화율에 있어서 EP 처리구가 소화율을 개선시켰다(p<0.05). 본 연구 결과는 2차적인 사료 가공 기술이 산란계에 서 계란 품질과 영양소 소화율을 개선하였다.

• 한국방사선학회논문지
• /
• 제9권1호
• /
• pp.47-53
• /
• 2015

본 연구에서 3.0 T에서 조영제 몰 농도에 따른 뇌 대사물질의 MR spectrum을 Phantom에서 PRESS 펄스 파형으로 분석하고자 하였다. 뇌 대사물질인 N-Acetyl Asparatate(NAA), Choline(Cho), Creatine(Cr)의 spectrum은 획득할 수 있었지만, Lactate(Lac)는 획득할 수 없었다. 조영제가 없는 대조군의 TR 2000 ms가 NAA, Cho에서 TR 1700 ms와 TR 1500 ms보다 높게 측정되었고, Cr에서는 TR 1500 ms에서 높게 측정되었다. 조영제가 희석된 TR 1700 ms에서 $0.1mmol/{\ell}$의 NAA 73%, Cho 249%, Cr 37%로 다른 TR 값보다 가장 높게 측정되었고, $0.3mmol/{\ell}$에서도 신호크기가 증가하였다. $0.5mmol/{\ell}$에서는 뇌 대사물질들의 신호크기가 감소하였으며, 특히 TR 1500 ms과 TR 2000 ms에서는 대조군보다도 감소하였다. NAA/Cr, Cho/Cr에서도 조영제 농도가 $0.1mmol/{\ell}$, $0.3mmol/{\ell}$, $0.5mmol/{\ell}$로 증가할수록 신호크기가 감소하였다. 조영제에 의한 MRS PRESS 펄스파형의 적정화를 위하여 3.0T에서 TR 2000 ms 보다 조영제 농도가 낮은 $0.1mmol/{\ell}$와 $0.3mmol/{\ell}$에서 신호크기가 가장 높고, 조영제 농도가 높은 $0.5mmol/{\ell}$에서는 신호크기가 가장 적게 감소한 TR 1700 ms로 반복시간을 단축시켜 사용하는 것이 유용할 것으로 사료된다.

• International Journal of Industrial Entomology and Biomaterials
• /
• 제12권1호
• /
• pp.41-43
• /
• 2006

Lamerin breed of the silkworm Bombyx mori L. is the only mulberry silkworm breed which survives with an associated microsporidian $(Lb_{ms})$ infection from generations. This present comparative investigation has produced information on the influence of $Lb_{ms}$ on the growth and development of the breed. The $Lb_{ms}$ transmits tranovarially as well as perorally at low level. Larvae developed from the eggs laid by female, infected with $Lb_{ms}$ were as normal as larvae developed from the eggs laid by healthy female. In infected tissues early developmental stages and mature spores located intracellularly but did not show hypertrophy of cells of the host. The meronts and sporonts measures $0.46{\pm}0.25,\;1.11{\pm}0.05{\mu}m$ in length and $0.32{\pm}0.05,\;0.78{\pm}0.10{\mu}m$ in width respectively. The mature spore measures $4.36{\pm}0.06{\mu}m$ in length and $2.14{\pm}0.01{\mu}m$ in width.