ABSTRACT
@#Carbon dots(CDs)were firstly prepared via a simple pyrolysis route using citric acid as the carbon precursor and glycine as modifier. The obtained CDs were further purified by n-butyl alcohol, which made the particle size more uniform and the fluorescence intensity stronger. When excited at 380 nm, the maximum emission wavelength of the CDs was about 480 nm, with a quantum yield of 47%. Based on fluorescence quenching, a novel method for chloramphenicol assay was developed with glycine-passivated CDs. This method is simple and rapid. A linear relationship between the change of fluorescence intensity and the concentration of chloramphenicol was obtained with a relation coefficient of 0. 999 7. The recovery was in the range of 99% to 101% with a relative standard deviation of 0. 3%, which shows CDs′ potential application in drug detection.
ABSTRACT
The related substances in docetaxel injection were identified by LC-MS/MS. Ethyl acetate was used to extract the injection to remove the pharmaceutical excipients. HPLC separation was carried out on a Hedera ODS-2 column (150 mm x 2.1 mm, 5 microm) with a mobile phase consisting of acetonitrile - 0.1% acetate acid aqueous solution (40: 60). Electrospray ionization source was set in the positive mode for the LC-ESI-MS/MS, and the ion monitoring modes were full scan and product ion scan. According to the mass spectra of the related substances, the fragment profiles were explained, and the chemical structures were elucidated. Docetaxel and its main related substances were well separated. Nine related substances in docetaxel injection were detected by LC-MS/MS. Their chemical structures were proposed, and four of them were identified in the docetaxel injection for the first time. The established LC-MS/MS method is effective in the separation and identification of the related substances in docetaxel injection. The test results are useful for its quality control.
ABSTRACT
UV second derivative spectrophotometry was used for the analysis of compounded Chinese medicinal prescription in order to eliminate interference from prescription base. Amplitude D and △A were taken as the quantitative informatious. Synthetic decanoyl acetaldehyde in compounded Chinese medicinal prescription were determined by two methods. The Correlation coefficicnts of the standard curve were found to be 0.9994 and 0.9996,the mean recovery to be 98.10% and 96 31%.