• 분석과학
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• 제32권2호
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• pp.48-55
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• 2019

The simple and effective analytical method for the quality control of a novel scalp tonic formulation has been developed and optimized in terms of HPLC conditions and sample preparation method, meanwhile, the optimization of preparation condition was using response surface methodology (RSM) based on central composite design (CCD). Oleanolic acid was selected as marker compound because of its bioactivities for alopecia therapy. The developed analytical method and extraction condition were successfully qualified. Coefficient of determination ($r^2$) for the calibration was 0.9997 with a line passing through the origin point in the range of 0.1-100 mg/mL. The limit of detection (LOD) and the limit of quantitation (LOQ) were 17.5 ng/mL and 55.0 ng/mL, respectively. The intra-day and inter-day precision of the method were 0.5-1.4 % and 0.7-1.8 % in relative standard deviation, respectively, while those accuracy were 99.5-100.9 % and 100.0-102.2 %, respectively. The repeatability of oleanolic acid in samples ranged of 0.3-1.9 % based on peak area and 0.3-0.7 % for retention time. Recoveries from samples were 95.0-99.4 % with lower than 1.8 % in relative standard deviation. Overall, the developed analytical method will be used for quality control of this commercial scalp tonic products successfully.

• Mass Spectrometry Letters
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• 제13권4호
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• pp.133-138
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• 2022

Taurine is a type of sulfur-containing amino acid having a sulfate functional group, that is biosynthesized from cysteine. It is mainly distributed in high concentrations in animal tissues and is known to have various effects such as osmotic pressure control, calcium control, anti-inflammatory, antioxidant, and hepatocellular protection. Also, taurine deficiency causes a variety of symptoms, including visual impairment. In particular, in the case of cats, taurine is not biosynthesized and must be supplied through food, so it is classified as an essential amino acid. In this study, an analysis method using mass spectrometry was developed instead of the commonly used derivatization method to quickly, environmentally, and precisely analyze taurine in various animal feeds. The developed analytical method showed good linearity (R² > 0.99), accuracy (81.97-105.78%), and precision (0.07-12.37%). In addition, the developed method was further verified through quantitative comparison with the derivatization method. This developed method was used in the determination of taurine in 20 animal feed samples obtained from South Korea. The levels of taurine found ranged from 81.53 to 6,743.53 mg/kg. The developed analysis method will be used for the detection and quantification of taurine in domestic feed.

• 분석과학
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• 제32권4호
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• pp.139-146
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• 2019

A simple and reliable analytical method based on high-performance liquid chromatography-ultraviolet detection was established for the analysis of the flowers of Chrysanthemum morifolium (CM). Luteolin-7-O-glucoside (LU7G) was chosen as a target analyte considering its content, availability, and ease of analysis. Chromatographic separation of LU7G was achieved using a Phenomenex Gemini $C_{18}$ column ($250{\times}4.6mm$, $5{\mu}m$) run with a mobile phase consisting of 0.5 % acetic acid in water and 0.5 % acetic acid in acetonitrile at a flow rate of $1.0mL\;min^{-1}$. The detection wavelength and column temperature were set at 350 nm and $40^{\circ}C$, respectively. Method validation was performed according to the AOAC guidelines and the method was specific, linear ($R^2=0.9991$ for $50-300{\mu}g\;mL^{-1}$), precise (${\leq}3.91%$RSD), and accurate (100.1-105.7 %). The limits of detection and quantification were 3.62 and $10.96{\mu}g\;mL^{-1}$, respectively. The established method was successfully applied to determine the contents of LU7G in various batches of bulk CM extracts and labscale CM extract. The developed method is a readily applicable method for the quality assessment of CM and its related products.

• 분석과학
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• 제18권2호
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• pp.168-172
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• 2005

A comparison study of XRF and $^{31}P$-NMR method for the analysis of phosphorous in lubricating oil has been described. Pure oil and water were used for the observation of matrices effect variation by different analytical methods. Quantitative analysis was carried out by XRF and $^{31}P$-NMR using real samples. Significant difference is observed from the slopes on the calibration curves by the XRF due to the matrices (water: 124.0, oil: 276.6). While the result obtained from XRF showed a large matrix effect, the slopes obtained from $^{31}P$-NMR results of two different matrices, however, are in good agreement ranged of ${\pm}9%$ (water: 4.9, oil: 5.3).

• 분석과학
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• 제25권4호
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• pp.214-222
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• 2012

ASTM (American Society for Testing and Materials) D6751-10은 바이오디젤의 품질 규격 뿐 아니라 분석방법 또한 제시하고 있다. 하지만 ASTM 표준에 따른 바이오디젤 및 포함된 여러 불순물의 품질 분석은 경제적, 시간적으로 부담이 크다. 본 연구는 적외선 분광분석법(infrared spectroscopy)과 다변량 통계분석법 중 하나인 PLS (partial least square method)를 이용하여 1회 측정만으로 바이오 디젤 및 불순물들의 농도를 분석하는 시스템을 개발하고자 하였다. 특히, 적외선을 이용한 분석에서 생기는 각 물질의 스펙트럼에 대한 산란 보정, 노이즈 감소 등을 위해 SNV, MSC, OSC, Savitzky-Golay 등의 4가지 전처리 방법의 성능을 비교하였다. 품질 분석에 필요한 바이오 디젤 검량 모델을 PLS로 모델링 결과, Savitzky-Golay 전처리를 하였을 때 정확도가 가장 우수함을 알았다.

• 분석과학
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• 제36권1호
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• pp.53-58
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• 2023

2'-Hydroxy-3',4'-methylenedioxy-3,4,5-trimethoxychalcone (HMTC) is a newly synthesized chalcone that affects proliferation, cytotoxic potential and apoptosis in human leukemia cells. However, no validated determination method has been described so far for HMTC in biological samples. Thus, we developed a liquid chromatographic method using a tandem mass spectrometry to determine HMTC in rat plasma. Liquid-liquid extraction with ethyl acetate was used for the clean-up procedure. The analyte was separated on a reversedphase column with mobile phase of distilled water and acetonitrile (2:8, v/v, including 0.1 % formic acid). The ion transition of the precursor to the product ion was principally deprotonated ions [M-H]^- at m/z 356.8 → 327.2 for HMTC. This analytical method was successfully applied in pharmacokinetic study of HMTC after intravenous administration in rats.

• Archives of Pharmacal Research
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• 제8권2호
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• pp.85-89
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• 1985

It was revealed that magnolol and honokiol isolated from the stem bark of Magnolia obovata, had potent antibacterial activity against Bacillus anthracis. A quantitative analytical method of magnolol and honokiol by HPLC has been established, and the amounts of the two components in the dried stem bark of M. obovata were 1, 94% and 0.44%, respectively.

• Bulletin of the Korean Chemical Society
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• 제19권11호
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• pp.1189-1193
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• 1998

The determination of total paraffin, naphthene, and aromatic (PNA) contents in naphtha samples, which were directly obtained from actual refining process, has been studied using near-infrared (NIR) spectroscopy. Each of the total PNA concentrations in naphtha has been successfully analyzed using NIR spectroscopy. Partial least squares (PLS) regression method has been utilized to quantify the total PNA contents in naphtha from the NIR spectral bands. The NIR calibration results showed an excellent correlation with those of conventional gas chromatography (GC). Due to its rapidity and accuracy, NIR spectroscopy is appeared as a new analytical technique which can be substituted for the conventional GC method for the quantitative analysis of petrochemical products including naphtha.

• 분석과학
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• 제25권6호
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• pp.395-401
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• 2012

본 연구에서는 PVC 제품에 잔류하는 염화비닐 단량체(VCM)에 대한 정량분석방법을 제시하였다. 용출용매의 경우, 에탄올, THF, 아세톤에서 유사한 추출효율을 나타내었으나, 노말헥산을 이용한 경우에는 상대적으로 낮은 추출효율을 보였다. 분쇄 PVC 시료에 VCM 표준용액을 주입한 분석시료에 대한 VCM 함유량 측정 결과, GC/MS를 이용한 직접주입법이나 헤드스페이스법 모두 양호한 결과를 나타내었다. PVC 제품의 중간물질인 스펀지에서의 VCM 분석과 관련하여 5 개 시험전문기관의 시험소간 비교시험 결과, 각 시험소간 결과 편차가 크지 않은 것으로 나타나 본 연구에서 제시한 전처리 및 분석방법에 대한 플라스틱 제품내의 VCM 정량방법이 유효한 것으로 판단되었다.

• 분석과학
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• 제14권5호
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• pp.384-391
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• 2001

본 연구에서는 ESI-MS/MS를 이용해 혈액내에서 아실카르니틴과 아미노산을 신속하게 정량분석하는 방법을 개발하였다. 아실카르니틴과 아미노산은 3N butanolic hydrogen chloride를 사용하여 유도체화 과정을 거친 뒤 이중질량분석기로 분석하였다. 아실카르니틴은 precursor 85 ion scan을 사용하여 분석하였고, 아미노산들중 알라닌, 발린, 루신/이소루신, 메티오닌, 페닐알라닌, 타이로신, 아스파르트산, 글루탐산 등은 neutral loss 102 scan, 오르니틴과 시트롤린은 neutral loss 119 scan, 글리신은 neutral loss 56 scan, 아르기닌은 neutral loss 161 scan 그리고 아르기니노석시닉산은 product ion 459 scan을 사용하여 분석하였다. 이 방법은 일반적인 액체 크로마토그래피나 아미노산 분석기에 비해서 시료의 전처리가 비교적 간단하며, 높은 감도와 좋은 재현성을 보여주었다.