• 분석과학
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• 제15권3호
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• pp.196-213
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• 2002

물 시료 중 알킬페놀류, 클로로페놀류 및 비스페놀 A의 동시분석을 기체크로마토그래피/질량분석기-선택이온검색법을 사용하여, US EPA 분석방법, isoBOC 유도체화 분석방법과 TBDMS 유도체화 분석방법을 비교하였다. 시료의 전처리는 유기용매로 추출하고 농축하여 분석한 방법과 XAD-4를 이용한 액체-고체 추출 후 isoBOC 유도체화와 TBDMS 유도체화를 실시하였다. 11종의 페놀류에 대한 회수율 실험은 3차 증류수에 각각 10 ${\mu}g/{\ell}$ (US EPA 방법) 또는 2 ${\mu}g/{\ell}$ (isoBOC 유도체화 분석방법과 TBDMS 유도체화 분석방법)의 농도를 대상으로 측정한 결과 각각 85.1~109.9%와 90.3~126.6%의 결과를 얻었다. 각 분석방법의 비스페놀 A에 대한 분석방법 검출한계는 US EPA 분석방법, isoBOC 유도체화 분석방법과 TBDMS 유도체화 분석방법이 각각 0.732 ${\mu}g/{\ell}$, 0.002 ${\mu}g/{\ell}$와 0.021 ${\mu}g/{\ell}$로 나타났으며, $5{\sim}400ng/{\ell}$의 농도 범위에서 isoBOC 유도체화 분석방법과 TBDMS 유도체화 분석방법 각각 0.9755~0.9981과 0.9908~0.9996의 직선성을 보였다. 폴리에틸렌 공장의 방류수를 대상으로 잔류량을 측정한 결과 일부페놀이 검출한계 이하에서 흔적으로 나타났다.

• Journal of Microbiology and Biotechnology
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• 제27권4호
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• pp.816-824
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• 2017

Human noroviruses are widespread and contagious viruses causing nonbacterial gastroenteritis. Real-time reverse transcription quantitative PCR (real-time RT-qPCR) is currently the gold standard for the sensitive and accurate detection of these pathogens and serves as a critical tool in outbreak prevention and control. Different surveillance teams, however, may use different assays, and variability in specimen conditions may lead to disagreement in results. Furthermore, the norovirus genome is highly variable and continuously evolving. These issues necessitate the re-examination of the real-time RT-qPCR's robustness in the context of accurate detection as well as the investigation of practical strategies to enhance assay performance. Four widely referenced real-time RT-qPCR assays (Assays A-D) were simultaneously performed to evaluate characteristics such as PCR efficiency, detection limit, and sensitivity and specificity with RT-PCR, and to assess the most accurate method for detecting norovirus genogroups I and II. Overall, Assay D was evaluated to be the most precise and accurate assay in this study. A ZEN internal quencher, which decreases nonspecific fluorescence during the PCR, was added to Assay D's probe, which further improved the assay performance. This study compared several detection assays for noroviruses, and an improvement strategy based on such comparisons provided useful characterizations of a highly optimized real-time RT-qPCR assay for norovirus detection.

• Journal of Microbiology and Biotechnology
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• 제19권11호
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• pp.1464-1469
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• 2009

To achieve more accurate and rapid detection of macrolide-lincosamide-streptogramin B resistance genes, erm(A), erm(B), and erm(C), we developed a TaqMan probe-based real-time PCR (Q-PCR) method and compared it with conventional PCR (C-PCR), which is the most widely using erm gene identification method. The detection limit of Q-PCR was 5 fg of genomic DNA or 5-8 CFU of bacterial cells of Staphylococcus aureus. The utilization of Q-PCR might shorten the time to erm detection from 3-4 h to about 50 min. These data indicated that Q-PCR assay appears to be not only highly sensitive and specific, but also the most rapid diagnostic method. Therefore, the appropriate application of the Q-PCR assay will permit rapid and accurate identification of erm genes from clinical and other samples.

• 한국환경보건학회지
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• 제22권1호
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• pp.36-44
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• 1996

A comparison was made of two detection methods(UV absorbence detection and fluorescence detection with pre-column derivatization, with trifluoroacetic acid) coupled with HPLC for the simultaneous determination of aflatoxin $B_1, B_2, G_1$ and $G_2$. A good separation of the four aflatoxins was achieved on a reversed-phase $C_{18}$ column (30 cm x 3.9 mm) with methanol-acetonitrile-water(20+20+60) for absorbence detection or acetonitrile-water(25+75) for fluorescence detection at the flow rate of 1.0 ml/min. The calibration graphs were linear over the ranges 100 ppb-1 ppm for $B_1/G_1$ and 30~300 ppb for $B_2/G_1$ with absorbence detection, and 1~500 ppb for $B_1/G_1$ and 0.3~150 ppb for $B_2/G_2$ with fluorescence detection. The correlation coefficients were greater than 0.94 and 0.99 for absorbance detection and for fluorescence detection, respectively. The detection limit was 100 ng for $B_1/G_1$ and 30 ng for $B_2/G_2$ with absorbence detection, and 1 ng for $B_1/G_1$ and 0.3 ng for $B_2/G_2$ with fluorescence detection. Recovery rates of aflatoxin $B_1, B_2, G_1$ and $G_2$ added to yeast-extract sucrose broth medium were 66.6%, 59.4%, 67.5% and 59.2%, respectively, for absorbence detection and 82.9%, 71.5%, 80.0% and 69.3%, respectively, for fluorescence detection. The four aflatoxins in culture medium were quantitatively detected by the two methods. The aflatoxins in the rice sample were not detected the absorbence detection method, but were below 10 ppb using the fluorescence detection method. Analysis of aflatoxins by both the absorbence and fluorescence methods coupled with HPLC showed acceptable linearity and good recovery. The absorbence detection was less timeconsuming and safer for treatment. The fluorescence detection was more elective and sensitive though elevated $B_1$ and $G_1$ contents were determined from the TFA-induced conversion of $B_1$ to $B_{2a}$ and $G_1$ to $G_{2a}$.

• Bulletin of the Korean Chemical Society
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• 제15권12호
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• pp.1038-1042
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• 1994

The amperometric responses of thiourea were studied in 0.1 M NaOH by flow injection analysis. D. C. amperometric and pulsed amperometric detection methods were applied for the determination of thiourea at novel metal electrodes such as Pt and Au. Triple-step potential waveforms were adopted in the pulsed amperometric detection. With an optimized pulsed waveform, the current for the oxidation of thiourea was examined with the variation of flow rate of carrier solution and with the change in the amount of sample injected. Gold working electrode turned out to be better in sensitivity and signal to noise ratio than Pt electrode in the pulsed amperometric detection of thiourea. Detection limit is estimated to be 5.33 ${\times}$ 10$^{-5}$ M with this detection method.

• 분석과학
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• 제14권5호
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• pp.392-399
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• 2001

생물시료에 존재하는 휘발성 유기화합물 중 n-butylbenzene과 1,2-dibromo-3-chloropropane (DBCP)를 기체크로마토그래피/질량분석기-선택이온검색법에 의해 수행하였다. 시료 중 휘발성 유기화합물은 $100{\mu}m$ polydimethyl siloxane (PDMS) fiber를 사용하여 headspace solid phase microextractio (SPME) 및 purge & trap 방법에 의해 추출 및 비교하였다. SPME에 의한 회수율은 n-butylbenzene의 경우 85.8%, DBCP의 경우 92.4%로 나타났고 검출한계는 각각 $0.15{\mu}g/kg$, $0.05{\mu}g/kg$로 나타났다. 반면, purge & trap의 경우 회수율은 n-butylbenzene의 경우 115.2%, DBCP의 경우는 80.9%로 나타났고 검출한계는 각각 $0.04{\mu}g/kg$ 및 $0.70{\mu}g/kg$로 나타나 두 방법에 있어 국내에서 규제하는 검출한계측면에서 큰 차이는 없었다.

• 한국동물위생학회지
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• 제45권3호
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• pp.243-248
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• 2022

The HPLC conditions for analysis of ivermectin in solutions dosage forms of commercial anthelmintics are different for each product. The purpose of this study was to establish a standardized chromatographic method for the quantification of ivermectin in solution. The separation was achieved on Waters Xbridge C18 column (4.6×150 nm, 5 ㎛) using different kinds of mobile phase composed of water/methanol/acetonitrile (15/34/51, v/v and 19.5/27.5/53, v/v), with UV detection at wavelengths 245 nm and 254 nm. A total of five commercial ivermectin in solution samples were analyzed. In this study, the optimal chromatographic conditions for analysis of ivermectin in solution were mobile phase of water/methanol/acetonitrile (15/34/51, v/v) at a flow rate of 1.0 mL/min and a detection wavelength of 245 nm using a Waters Xbridge C18 column (4.6×250 nm, 5 ㎛) at a column temperature of 25℃. The linearity was observed in the concentration range of 50~150 ㎍/mL, with a correlation coefficient, r²= 0.99999. The limit of detection and the limit of quantification were 0.88 and 2.68 ㎍/mL, respectively. The accuracy (% recovery) was found to be 98.9 to 100.3%. Intra-day and Intermediate precisions with relative standard deviations were less than 1.0%. The content of ivermectin for five market samples ranged 91.2~102.7%. The proposed method was also found to be robust, therefore, the method can be used for the routine analysis of ivermectin in solutions dosage forms.

• 혜화의학회지
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• 제22권1호
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• pp.129-143
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• 2013

This study was conducted to investigate the residue amount of pesticide on the 41 medicinal herbs in Daejeon area. This study was carried out to monitor the current status of pesticide residues in commercial medicinal herbs for sale of food use in 2012. It was performed using GC/ECD, GC/NPD, HPLC to analyze pesticides residues. Residues of 283 pesticides were analyzed by a simultaneous multiresidue method in 41 medicinal herbs being on sale in Daejeon. The medicinal herbs detected pesticides in 10 of 41 cases, showed a detection rate of 24.39%. The medicinal herbs which exceed the maximum residue limit were five cases as Cnidii Rhizoma, Osterici Radix, Artemisiae Capillaris Herba, Zizyphi Fructus and Alismatis Rhizoma. And pesticide residue of Cnidii Rhizoma and Alismatis Rhizoma exceeds the limit standard presented in only medicine use of KFDA. The residual pesticides which had the high detection rate were Chlopyrifos, Tebuconazole and Endosulfan in the detection of medicinal herbs. For further research, standards of Pesticide Residues in medicinal herbs should be added and more research of pesticide residues in medicinal herbs required. And standards of pesticide residues in medicinal herbs should be applied equally as medicines and food.

• Parasites, Hosts and Diseases
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• 제47권3호
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• pp.293-297
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• 2009

Improved methods for detection of Cryptosporidium oocysts in environmental and clinical samples are urgently needed to improve detection of cryptosporidiosis. We compared the sensitivity of 7 PCR primer sets for detection of Cryptosporidium parvum. Each target gene was amplified by PCR or nested PCR with serially diluted DNA extracted from purified C. parvum oocysts. The target genes included Cryptosporidium oocyst wall protein (COWP), small subunit ribosomal RNA (SSU rRNA), and random amplified polymorphic DNA. The detection limit of the PCR method ranged from $10^3$ to $10^4$ oocysts, and the nested PCR method was able to detect $10^0$ to $10^2$ oocysts. A second-round amplification of target genes showed that the nested primer set specific for the COWP gene proved to be the most sensitive one compared to the other primer sets tested in this study and would therefore be useful for the detection of C. parvum.

• Journal of Microbiology and Biotechnology
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• 제25권11호
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• pp.1782-1786
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• 2015

A new improved PCR method has been developed for the rapid, reliable, and sensitive detection of Venturia nashicola, a destructive pathogen of scab disease in Japanese pear. The translation elongation factor-1 alpha gene-derived PCR primers specifically amplified a 257-bp-sized DNA band of the target gene from the genomic DNA of V. nashicola. No amplicon was produced from the genomic DNA of other Venturia spp. and reference fungal species tested. With the high detection limit of 10 fg DNA content, our real-time method could be used for the quarantine inspection and field monitoring of V. nashicola.