• 한국환경과학회지
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• 제4권3호
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• pp.249-258
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• 1995

PCBs have been measured using GC-ECD, GC-MS, GC-ELCD, HPLC, TLC, NMR and Immunoassay. The analysis of PCBs using GC-ECD include the peak pattern method as none derivatization and the Perchlorination method as derivatization. This study was conducted to establish the perchlorination method with Sbcls from PCBs to decachlorinated biphenyl(DCB). The aroclor 1242 of PCBs was chlorinated and then, converted into the DCB which showed a single peak in GC-ECD chromatogram. The detection limit of DCB was 2pg. The quantification detection concentration of PCBs extracted with soxhlet was 0.5ng/g in the soil. PCBs were not detected in the suburban soil, but 174ng/g in the soil of industrial complex. Mean PCBs concentration of Shinchun stream at Kumho river and Jinchun stream at Nakdong river was calculated average 낙ngjg in 각e sediment. PCBs concentration in the sediment of Kumho river near 2-7km from conjunction with Nakdong river was average 154ng/g. PCBs concentration in the sediment of Nakdong river near conjunction with Kumho river was average 159ng/g.

• Bulletin of the Korean Chemical Society
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• 제33권1호
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• pp.171-176
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• 2012

A novel chemiluminescence (CL) system was established for the determination of cytosine arabinoside (Ara-C) in pharmaceutical preparations. It was showed that a clear CL signal was observed when Eosin Y mixed with Fenton reagent. The CL intensity was decreased significantly when Ara-C was added to the reaction system and partially scavenged the hydroxyl radicals in the solution. The extent of decrease in the CL intensity had a good stoichiometrical relationship with the Ara-C concentration. Based on this, we developed a new method for the determination of Ara-C using a flow injection analysis (FIA) technique with CL detection. Under the optimal conditions, the linear range of Ara-C concentration was $6.0{\times}10^{-9}\sim1.0{\times}10^{-7}mol/L$ (R = 0.9982) with a detection limit of $7.6{\times}10^{-10}mol/L$ (S/N=3), the RSD was 5.6% for $6.0{\times}10^{-8}mol/L$ Ara-C (n = 11). The method was successfully applied to the determination of Ara-C in injection samples. The possible chemiluminescence reaction mechanism was discussed.

• 동아시아식생활학회지
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• 제16권5호
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• pp.585-591
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• 2006

We report a novel HPLC method for analyzing the capsaicinoids and nonivamide. The following conditions were used: a total column and column temperature of $3^{\circ}C$, a detection wavelength of 280 nm, an eluent containing acetonitrile : 0.5% formic acid(31:69, v/v). The experimental data was compared with standard nonivamide and capsaicin. The results showed that nonivamide was eluted in 96.7 minutes with a recovery ratio of 96.5% after adding known nonivamide. In addition, the detection limit for nonivamide was 18.6 ng. The capsaicinoids from Korean pepper were extracted (after blooming 60th) from 3 breeds cultivated in Korea, Buchon, Chungyang and Hanbando. and crisis it analyzed sympathizes the nonivamide in the result nonivamide from the Buchon and the Chungyang which are not detected from the Hanbando $0.16{\sim}0.24{\mu}g/g$ it detects with very small amount it contains it confirmed the each capsaicinoid with the HPLC and the LC-MS. These results are expected contribute to the quality control of various product processes, which includes product delivery inspection as well as examining the capsaicinoids present in the product for possible medicine manufacture and various foodstuff, and the nonivamide content, which may be a feed for various manufacturing processes involving chemical synthesis.

• Archives of Pharmacal Research
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• 제19권6호
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• pp.469-474
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• 1996

A rapid and sensitive method has been developed to detect hepatitis B virus DNA (HBV) by nested polymerase chain reaction (PCR) technique with primers specific for the surface and core regions in capillary thermal cycler within 80 min. The lower limit for detection by present PCR method is $10^{-5}$ pg of recombinant HBV DNA which is equivalent to that determined by one round of PCR amplification and Southern blot hybridization analysis. When boiled HBV positive serum was serially diluted 10-fold, HBV DNA was successfully determined in $1{\mu}l-10^{-3}$ of serum. HBV DNA was detected by present method in 69 clinical samples including HBsAg positives and negatives by enzyme-linked immunosorbent assay (ELISA). When serum samples were amplified by nested PCR using surface and core region primers, HBV DNAs were detected in 37 of 69 samples (53.6%) and 18 of 69 samples (26.1%), respectively. These results can inform the infectious state of HBsAg positive pateints. A simple and rapid nested PCR protocol by using boiled serum as DNA template has been described for the clinical utility to determine HBV DNA in human serum.

• Journal of Microbiology
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• 제38권2호
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• pp.105-108
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• 2000

Oligonucleotide primers amplifying a 344 bp fragment on the integrin-like protein alpha-INT1p gene (${\alpha}$INT1) of Candida albicans were synthesized for screenign of C. albicans from clinicalsamples by the polymerase chain reaction (PCR). The PCR specifically amplified DNA from C. albicans and none from any other Candida, fungal, or human DNA in standard used here. The PCR assay showed that the primers (LH1 and LH2) were specific for 26 isolates of C. albicans from clinical smaples, whereas the positive fragment, 344 bp, was not amplified from 15 clinical isolates including 14 other medically important Candida species and an isolate of Saccharomyces cerevisiae. PCR was conducted on the urine samples of 20 patients and 4 samples were C. albicans positive. The detection limit of the PCR assay for C. albicans was shown to be approximately 10 cells/ml saline. The PCR system using 344 bp ${\alpha}$INT1 as a target is more specific and rapid than the conventional culture method, and the sensitive detection method is applicable to clinical diagnosis of C. albicans infections.

• Animal Bioscience
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• 제34권9호
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• pp.1532-1543
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• 2021

Objective: This study was aimed to establish a quantitative detection method for meat contamination based on specific polypeptides. Methods: Thermally stable peptides with good responses were screened by high resolution liquid chromatography tandem mass spectrometry. Standard curves of specific polypeptide were established by triple quadrupole mass spectrometry. Finally, the adulteration of commercial samples was detected according to the standard curve. Results: Fifteen thermally stable peptides with good responses were screened. The selected specific peptides can be detected stably in raw meat and deep processed meat with the detection limit up to 1% and have a good linear relationship with the corresponding muscle composition. Conclusion: This method can be effectively used for quantitative analysis of commercial samples.

• 분석과학
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• 제36권6호
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• pp.281-290
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• 2023

Zidovudine is an antiretroviral agent prescribed for the prevention and treatment of human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS). It is typically recommended to be used in combination with other antiretroviral drugs. Zidovudine has the potential to generate N-nitrosodimethylamine (NDMA) in the presence of dimethylamine and nitrite salt under acidic reaction conditions during the drug manufacturing process. NDMA is a potent human carcinogen that may be detected in drug substances or drug products. An analytical method was developed to determine NDMA in pharmaceuticals including zidovudine using high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The analysis involved reversed-phase chromatography on a Kinetex F5 column with a mobile phase comprising water-acetonitrile mixtures. The detection of positively charged ions was conducted using atmospheric pressure chemical ionization (APCI). The calibration curve demonstrated excellent linearity (r = 0.9997) across the range of 1-50 ng/mL with a highly sensitive limit of detection (LOD) at 0.3 ng/mL. The developed method underwent thorough validation for specificity, linearity, accuracy, precision, robustness, and system suitability. This sensitive and specific analytical method was applied for detecting NDMA in zidovudine drug substance and its formulation currently available in the market, indicating its suitability for drug quality management purposes.

• Journal of Microbiology and Biotechnology
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• 제34권6호
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• pp.1322-1327
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• 2024

The accurate and rapid detection of methicillin-resistant Staphylococcus aureus (MRSA) holds significant clinical importance. This work presents a new method for detecting methicillin-resistant Staphylococcus aureus (S. aureus) in clinical samples. The method uses an aptamer-based colorimetric assay that combines a recognizing probe to identify the target and split DNAzyme to amplify the signal, resulting in a highly sensitive and direct analysis of methicillin-resistance. The identification of the PBP2a protein on the membrane of S. aureus in clinical samples leads to the allosterism of the recognizing probe, and thus provides a template for the proximity ligation of split DNAzyme. The proximity ligation of split DNAzyme forms an intact DNAzyme to identify the loop section in the L probe and generates a nicking site to release the loop sequence ("3" and "4" fragments). The "3" and "4" fragments forms an intact sequence to induce the catalytic hairpin assembly, exposing the G-rich section. The released the G-rich sequence of LR probe induces the formation of G-quadruplex-hemin DNAzyme as a colorimetric signal readout. The absorption intensity demonstrated a strong linear association with the logarithm of the S. aureus concentration across a wide range of 5 orders of magnitude dynamic range under the optimized experimental parameters. The limit of detection was calculated to be 23 CFU/ml and the method showed high selectivity for MRSA.

• Journal of Microbiology and Biotechnology
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• 제26권8호
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• pp.1457-1463
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• 2016

Vibrio anguillarum, a devastating pathogen causing vibriosis among marine fish, is prevailing in worldwide fishery industries and accounts for grievous economic losses. Therefore, a rapid on-site detection and diagnostic technique for this pathogen is in urgent need. In this study, two mouse monoclonal antibodies (MAbs) against V. anguillarum, 6B3-C5 and 8G3-B5, were generated by using hybridoma technology and their isotypes were characterized. MAb 6B3-C5 was chosen as the detector antibody and conjugated with quantum dots. Based on MAb 6B3-C5 labeled with quantum dots, a modified dot blot assay was developed for the on-site determination of V. anguillarum. It was found that the method had no cross-reactivity with other than V. anguillarum bacteria. The detection limit (LOD) for V. anguillarum was 1 × 10³ CFU/ml in cultured bacterial suspension samples, which was a 100-fold higher sensitivity than the reported colloidal gold immunochromatographic test strip. When V. anguillarum was mixed with turbot tissue homogenates, the LOD was 1 × 10³ CFU/ml, suggesting that tissue homogenates did not influence the detection capabilities. Preenrichment with the tissue homogenates for 12 h could raise the LOD up to 1 × 10² CFU/ml, confirming the reliability of the method.

• The Plant Pathology Journal
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• 제39권5호
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• pp.486-493
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• 2023

Cowpea mild mottle virus (CPMMV) is a global plant virus that poses a threat to the production and quality of legume crops. Early and accurate diagnosis is essential for effective managing CPMMV outbreaks. With the advancement in isothermal recombinase polymerase amplification and lateral flow strips technologies, more rapid and sensitive methods have become available for detecting this pathogen. In this study, we have developed a reverse transcription recombinase polymerase amplification combined with lateral flow strips (RT-RPA-LFS) method for the detection of CPMMV, specifically targeting the CPMMV coat protein (CP) gene. The RT-RPA-LFS assay only requires 20 min at 40℃ and demonstrates high specificity. Its detection limit was 10 copies/µl, which is approximately up to 100 times more sensitive than RT-PCR on agarose gel electrophoresis. The developed RT-RPA-LFS method offers a rapid, convenient, and sensitive approach for field detection of CPMMV, which contribute to controlling the spread of the virus.