21196-84-9

Upstream product

• 10416-59-8 N,O-bis-(trimethylsilyl)-acetamide 
• 56-75-7 chloramphenicol 
• 75-77-4 chloro-trimethyl-silane 

Relevant academic research and scientific papers

Matrix solid-phase dispersion extraction and gas chromatographic determination of chloramphenicol in muscle tissue

A method based on matrix solid-phase dispersion (MSPD) was developed for the gas chromatographic (GC) determination of chloramphenicol (CAP) residues in animal muscle tissue. Muscle tissue was blended with octadecylsilyl-derivatized silica (C18). A column made from the C18/muscle tissue matrix was washed with n-hexane and acetonitrile/water (5 + 95), after which CAP was eluted with acetonitrile/water (50 + 50) and partitioned into ethyl acetate. The final extract was evaporated, and a trimethylsilyl derivative of CAP was prepared with Sylon HTP and detected by GC with an electron capture detector (ECD) and a mass spectrometer. For quantitation, the internal standard used was the meta isomer of CAP (m-CAP) for GC-ECD. Muscle tissue samples were fortified at three concentration levels. At 5, 10, and 15 μg/kg levels the respective mean recoveries were 93, 96, and 98%, and the repeatabilities were 13, 11, and 3%. The detection and quantitation limits with ECD were 1.6 and 4.0 μg/kg, respectively. No statistically significant difference was observed in the efficiency of CAP extraction from muscle tissue of various animals (bovine, porcine, and poultry) by the MSPD technique.

Detection of residual chloramphenicol, florfenicol, and thiamphenicol in yellowtail fish muscles by capillary gas chromatography-mass spectrometry

Chloramphenicol (CAP), florfenicol (FF), and thiamphenicol (TAP) were extracted from yellowtail muscles with ethyl acetate, and the extract was evaporated. The residues was dissolved with sodium chloride solution and partitioned with n-hexane to remove lipids, and then the drugs were extracted with ethyl acetate. After evaporation of ethyl acetate extract, the residue was dissolved with n-hexane followed by ethyl ether and applied to a Sep-Pak Florisil cartridge successively. The drugs were eluted from the cartridge with methanol-ethyl ether (3:7), and eluate was evaporated to dryness. After acetonitrile and BSA were added to the residues, the drugs were derivatized at 50 °C for 10 min. After the solvent was evaporated, the residue was dissolved with ethyl acetate and applied to gas chromatography-mass spectrometry. The drugs were separated by a capillary column coated with 5% phenyl methyl silicone, and SIM was performed at m/z 208 and 225 for CAP, at mlz 257 for FF, and at mlz 242, 257, and 330 for TAP. Recoveries of each drug from yellowtail muscle fortified at 0.1 ppm were more than 65%, and detection limits were 5 ppb.

Attempts at gas chromatographic determination of chloramphenicol and azidamfenicol as trimethylsilyl ethers

Chloramphenicol can be determined by gas chromatography as its O,O-bis(trimethylsilyl) ether. Quantitative investigations have shown, however, that some of the methods described in the literature for introduction of the silyl group do not give a complete reaction and are also insufficiently reproducible. It is shown that the reactions with hexamethyldisilazan or with bis(trimethylsilyl)acetamide in acetone are suitable for the purpose as these reactions take place quantitatively and the results of gas chromatography are satisfactorily reproducible. Studies of the technique of quantitative gas chromatography show that the results are decisively influenced by the reproducibility of the dosage and of the product identification by the detector reagent. A procedure is suggested in which, in addition to the analytical chromatogram, reference chromatograms are run with solutions containing known amounts of the silyl compound specially prepared in a pure state (relative standard deviation 1 to 2%). The 0,0-bis(trimethylsilyl) ether of azidamphenicol has been prepared and its gas chromatographic behavior investigated. Results showed that this compound cannot be satisfactorily determined by gas chromatography under the conditions used for the corresponding chloramphenicol ether.