• Journal of Pharmaceutical Investigation
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• 제21권3호
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• pp.179-188
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• 1991

An HPLC assay method of a drug to be applied to the pharmacokinetic studies of the drug should be completely validated. The validation process for an HPLC assay method in a biological sample was discussed using the data obtained from the development of HPLC method for the simultaneous quantitation of verapamil and norverapamil in human serum. The validation criteria included were specificity, linearity, accuracy, precision, sensitivity, recovery, drug stability, and ruggedness of an assay method.

• 한국수산과학회지
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• 제46권2호
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• pp.147-153
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• 2013

To prevent paralytic shellfish poisoning (PSP) due to the consumption of shellfish contaminated with PSP toxins, the quantitative analysis of these toxins is very crucial. The AOAC International mouse bioassay (MBA) has been used widely for the routine monitoring of PSP toxins for more than 50 years. However, this method has low sensitivity and high limit of quantification (LOQ) and interferences from other components in the extract, and it cannot determine toxic profiles. Ethical problems also exist with the continued use of this live mouse assay. To establish an alternative method to the MBA used for PSP toxins analysis, we attempted to optimize the analysis conditions of a precolumn high-performance liquid chromatography (HPLC) oxidation method and succeeded in validating its accuracy and precision in quantifying PSP toxins. A clear peak and the isolation of PSP toxins were obtained by injecting the working standards of Certified Reference Materials using HPLC. The LOQ of the precolumn HPLC oxidation method for PSP toxins was about $0.1002{\mu}g/g$, which represented an approximately fourfold improvement in detection capability versus the AOAC MBA. The intra-accuracy and precision for PSP toxins in oysters were 77.0-103.3% and 2.0-5.7%, respectively, while the respective inter-accuracy and precision were 77.3-100.7% and 2.4-6.0%. The mean recoveries of PSP toxins from oysters were 75.2-112.1%. The results of a comparison study showed good correlation between the results of the precolumn HPLC oxidation method and those of MBA, with a correlation factor of 0.9291 for mussels. The precolumn HPLC oxidation method may be used as an alternative to, or supplementary method with, MBA to monitor the occurrence of PSP toxins and to analyze the profiles of these toxins in shellfish.

• Journal of Pharmaceutical Investigation
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• 제21권3호
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• pp.171-177
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• 1991

A reverse-phase, ion-pair high performance liquid chromatographic (HPLC) method for the simultaneous quantative determination of pyridostigmine and its hydrolytic product, 3-hydroxy-N-methylpyridinium (HMP), is descrihed, The assay of pyridostigmine and HMP was linear in the range of amount from 24 to 60 mg/tablet and from 2.4 to 12.0 mg/tablet, respectively, with coefficient of variation (C.V.) of 0.05-0.12% (n=7) and 0.25-0.52% (n=5), respectively, and applicable conveniently even in the case of the mixture of pyridostigmine and HMP. Meanwhile, the conventional UV method gave inaccurate results for the aged pyridostigmine tablets. In the extraction of pyridostigmine from tablets prior to be assayed by HPLC, methanol was found to be more effective than ethanol or distilled water. Multiple extraction (four times) with methanol resulted in the full recovery of pyridostigmine, whereas ethanol gave 95% recovery even after four times extraction. Based on these results. the present method would be very useful for the accurate determination of pyridostigmine in the aged pyridostigmine tablets.

• Bulletin of the Korean Chemical Society
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• 제27권11호
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• pp.1923-1926
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• 2006

• 한국식품과학회지
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• 제36권2호
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• pp.189-195
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• 2004

본 연구에서는 조제분유 중에 영양강화를 위해 첨가하는 비타민 A와 E의 함량측정을 위해 각기 다른 실험방법을 사용하지 않고 2가지 비타민을 동시에 분석하는 신속분석법을 위와 같이 수행하였다. 비타민 A와 E를 유기용매로 동시에 신속하게 추출하고 역상컬럼과 PDA-HPLC를 이용하여 각각의 성분으로 모두 분리한 후 동시에 검출하는 방법을 사용하였다. 국제표준인증물질 및 조제분유를 시료로 사용하여 본 연구의 실험방법에 의해 측정된 값을 식품공전방법 및 AOAC방법에 의한 측정값과 비교한 결과 유사한 측정결과를 얻을 수 있었다. 또한 본 연구의 실험방법에 의하여 수행한 국제인증표준물질중의 비타민 A와 E의 함량측정 결과는 인증된 표준값내의 결과를 보여주었다. 따라서, 비타민 A또는 E를 강화한 분유, 이유식 등의 분말 유제품 중에서 비타민 A와 E의 함량을 측정 하고자 할 때 한정된 장비와 인력으로 각각의 2가지 실험방법을 수행하기가 어렵거나 시간단축이 필요한 경우, 본 연구에서 수행한 실험방법과 같이 시료 전처리를 간단하고 신속하게 수행할 뿐만 아니라 역상컬럼과 PDA-HPLC에 의해 비타민 A와 E를 동시에 분석함으로써 보다 효율적인 분석을 진행 할 수 있을 것으로 사료된다.

• Natural Product Sciences
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• 제25권3호
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• pp.275-283
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• 2019

In this study, we described the new developed method to simultaneously discriminate two herbal drugs of Artemisiae Argyi Folium and Artemisiae Iwayomogii Herba using eight marker compounds (1 - 8) on an HPLC-PDA system. The developed method was applied to quantify the major components of two herbal drugs. The pattern analysis successfully discriminated and evaluated different components between Artemisiae Argyi Folium and Artemisiae Iwayomogii Herba. Results were used for classification of different species from collected samples.

• Journal of Applied Biological Chemistry
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• 제57권4호
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• pp.301-305
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• 2014

On-line screening high performance liquid chromatography (HPLC)-$ABTS^+$ assay를 이용한 청호로부터 chlorogenic acid, caffeic acid, vitexin, queretin, aremisinin의 항산화 활성을 온라인스크리닝 하였다. 이때 침적방법을 적용한 추출시간과 추출용매 조성으로부터 추출효율을 확인하였다. 이 결과 100% 물 추출물에서 수율이 가장 좋왔고 chloroenic acid의 항산화 활성이 가장 높았다. 또한 on-line screening HPLC-$ABTS^+$ assay 분석은 천연물에서 항산화 활성을 신속하게 탐색하는데 효율적이다.

• Natural Product Sciences
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• 제25권2호
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• pp.122-129
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• 2019

The roots of Phlomis umbrosa (Turcz.) (Phlomidis Radix) have been traditionally used to treat cold, reduce swelling and staunch bleeding. Four iridoids (1 - 3 and 5) and six phenylethanoid derivatives (4, and 6 - 10) were isolated from the roots of P. umbrosa. A simple, sensitive, and reliable analytical HPLC/PDA method was developed, validated, and applied to determine 10 marker compounds in Phlomidis Radix. Furthermore, the isolates were evaluated for cytotoxic and anti-oxidant activities as well as DPPH-HPLC method. Among them, compounds 4 and 6 - 9 displayed potent anti-oxidant capacities using DPPH assay with $IC_{50}$ values of $27.7{\pm}2.4$, $10.2{\pm}1.1$, $18.0{\pm}0.8$, $19.1{\pm}0.3$, and $19.9{\pm}0.6{\mu}M$, and compounds 6, 8, and 9 displayed significant cytotoxic activity against HL-60 with $IC_{50}$ values of $35.4{\pm}3.1$, $18.6{\pm}2.0$, and $42.9{\pm}3.0{\mu}M$, respectively.

• 대한본초학회지
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• 제22권2호
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• pp.97-102
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• 2007

Objectives : This study presents a high performance liquid chromatography - electrospray ionization-mass spectrometer (HPLC-MS/MS) methods for the quantitative and qualitative analysis of various active components in Samul-tang, which is composed of four crude herbs. Methods : HPLC-ESI-MS/MS for the determinations of paeoniflorin and 5-HMF (5-hydroxymethyl 2-furaldehyde) in the Samul-tang, the separation method was performed on an COSMOS1L 5C18-AR-Il (2.0 X 150 mm I.D.) column by gradient elution with 0.1% acetic acid and 5% CH3CN in water (A)-0.1% acetic acid and 5% H20 in CH3CN (B) as the mobile phase at a flow-rate of 300 ${\mu}L/min$ with detection at quadrupole mass spectrometer. The all marker substances were always detected as the base peaks in the positive ion mode. Results : The paeoniflorin of Paeoniae Radix in Samul-tang showed a strong base peak [M+H2O]+ in the positive detection mode to give the following as; paeoniflorin (498.109 [M+H2O]+, 479.8 [M]+, 301 [M-glucose]+, 179.3 [glucose]+). Based on the HPLC retnetion time and MS of standard compounds confirmed the identity of active compounds in Rehmanniae Radix Preparata as follows; 5-HMF (127.0[M+H]+, 109.3 [M-OH]+) in the positive ion mode. Conclusion : According to the above results, HPLC-ESI-MS method permits assignment of tentative structures such as paeoniflorin and 5-HMF in the Samul-tang.

• 대한원격탐사학회지
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• 제18권1호
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• pp.35-42
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• 2002

The results of our observation in May 2000 indicated that the SeaWiFS algorithm (O'Reilley et al., 1998), which was adopted for OSMI data processing, overestimated the actual chlorophyll values. This was rather unexpected in that there were good reasons to expect that the bio-optical properties of East/Japan Sea belonged to Case 1 water and in such case, the OC2 algorithm would give unbiased estimates of actual chlorophyll a values. In November 2000, a cruise conducted bio-optical surveys in the same area. This time we added HPLC (High Performance Liquid Chromatography) method for measuring chlorophyll a concentration to the standard fluorometric method, which we hale been using during the past Fluorometric method with acidification is known to result in under/overestimation of chlorophyll values in many parts of the world oceans, while it is easier and cheaper than HPLC method. To our surprise, the comparison of HPLC chlorophyll and fluorometric chlorophyll values show that fluorometric values gave an underestimation up to 50%. This error was due to the presence of accessory pigments such as chlorophyll b. Considering this error, our precious result of May 2000(Yoo et al., 2000) might have to be reinterpreted. Calculation of reflectance at 490 and 555nm, however, indicated that this is not still enough to explain the discrepancies.