Direct Detection Of Chloramphenicol In Honey By Neutral Desorption-Extractive Electrospray Ionization Mass Spectrometry

Antimicrobial drugs, which can inhibit the protein synthesis activity of bacterial, are widely used in prevention of bee diseases by beekeepers. However, excessive intake antimicrobial drugs can result in aplastic anemia and other fatal chronic diseases. For a long time, the Antimicrobial drugs residues in honey has seriously affected China’s honey industry. Chloramphenicol (CAP) is a broad-spectrum antibiotic, which is widely used in bee industry by beekeepers. Although there are many traditions detection methods for CAP, they all need long time sample pretreatment, sample pollution, time-consuming, and difficult to apply to actual analytical. So we must find a high sensitivity, rapid analysis and high specificity for quantitative analysis of CAP in honey sample.In this study, we made the methanol and silver nitrate solution as extractant, constructed a novel platform of neutral desorption-extractive electrospray ionization mass spectrometry for direct, rapid detection of CAP in honey sample without any sample pretreatment. The results of this study are as follows:1. Made ND-EESI-MS as the CAP detection method in honey in this study. In the early study, we use Surface Desorption Atmospheric Pressure Chemical Ionization, Desorption Electrospray Ionization, ND-EESI method, and CAP standard solution to do MS experiment. The result showed that we just can get the right MS/MS" spectrum which was as same as the literature by ND-EESI. So we made ND-EESI-MS as the detection method.2. In the ND-EESI-MS experiment which made methanol:water:ammonia (98:1:1) as the extractant, we get the best neutral desorption spray reagent and best working conditions under the optimized experiment. For CAP in honey, the linear range was from 100 ng/mL to 8000 ng/mL. The concentration of chloramphenicol in honey were determined to be 400 ng/mL,3000 ng/mL, and the limit of determination was 15.6 ng/mL. The recoveries of real sample analysis were 92.9%,83%, the relative standard deviation were 3.5%,5.8%. The results showed that ND-EESI-MS was a powerful analytical platform to provide high sensitivity, high precision, rapid analysis and high specificity for quantitative analysis of CAP in honey sample without any sample pretreatment.3. In the ND-EESI-MS experiment which made silver nitrate solution as the extractant, we use methanol as neutral desorption spray reagent, and get the best working conditions under the optimized experiment. For CAP solution, the linear range was from 5 ng/mL to 500 ng/mL. The concentration of CAP solution were determined to be 20 ng/mL,50 ng/mL, and the recoveries of real sample analysis were 81%,83.1%, the relative standard deviation were 8.2%,7.9%. Our results showed that ND-EESI-MS was rapid analysis for quantitative analysis of CAP in honey sample without any sample pretreatment.In conclusion, we overcome the drawbacks of traditional methods, and established a new detection method which was high sensitivity, high precision, rapid analysis and high specificity for quantitative analysis of CAP in honey without any sample pretreatment, it is significant to the the honey industry and the development of food security.