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Article in Chinese | WPRIM | ID: wpr-879093


In this experiment, an ultra-high performance liquid chromatographytandem triple quadrupole mass spectrometry was established for the determination of caffeine in commercially available Ginkgo Folium. The samples were extracted by ultrasonic method with methanol, and separated on Waters CORTECS T3 column(2.1 mm×100 mm, 2.7 μm), with mobile phase of 0.1% formic acid solution-0.1% formic acid acetonitrile solution for gradient elution, at flow rate of 0.3 mL·min~(-1); column temperature of 30 ℃, and injection volume of 2 μL. Mass spectrometry was conducted at ESI~+ multiple reaction monitoring(MRM) mode; quantitative analysis was conducted with external standard method. The results showed that in the range of 0.099 6-9.96 ng·mL~(-1), there was a good linear relationship between the mass concentration of caffeine and the peak area, R~2=0.999; the average recovery was 84.51%, with RSD of 6.2%. The results of precision, repeatability and stability showed that the RSD was 5.1%, 5.9%, 7.2%, respectively. The content range of caffeine in 10 batches of Ginkgo Folium was 1.52-60.86 μg·kg~(-1). In conclusion, this method is accurate, reliable and reproducible, which provides a reference for the safety study of Ginkgo Folium.

Caffeine , Chromatography, High Pressure Liquid , Ginkgo biloba , Tandem Mass Spectrometry
Article in Chinese | WPRIM | ID: wpr-845167


Objective: To compare and analyze 7 new coronavirus nucleic acid detection kits and 5 nucleic acid extraction methods. Methods: After extracting nucleic acids from 44 positive coronavirus clinical samples, 7 SARS-CoV-2 nucleic acid detection kits were used for RT-PCR amplification experiments to compare the positive rate and Ct value;33 new coronavirus positive clinical samples were selected to compare the acid extraction methods. Five different nucleic acid extraction methods were used to extract the samples, and then RT-PCR amplification experiments were performed to compare the positive rate and Ct value. Results: The brand A nucleic acid extraction kit had the highest positive rate and the lowest rate of missed detection;comparison of nucleic acid extraction methods showed that the manual column extraction method had the highest positive rate, followed by the magnetic bead extraction method, and the one-step extraction method had the highest missed detection rate. Conclusion: The detection capabilities of the SARS-CoV-2 detection kits are uneven, so evaluation work needs to be done before the selection of the kit. The manual column extraction method showed best extraction efficiency but took a long time. Because of the possible combination with the automatic nucleic acid extraction instrument, the magnetic bead extraction method had a high extraction efficacy, which might be suitable for use in the ex- traction of large batches of samples. Although the one-step extraction method was easily operable, the method had a high missed detection rate, so this method was not recommended for clinical use.