The Study On Mycotoxins Detection Technology And Its Application In Maize

Mycotoxins are secondary metabolites produced by micro-fungi, some of which are carcinogenic, teratogenic, mutagenic. The plant area of corn is the largest in the whole world, and corn's production was about 219.7 million tons in 2015 in China. In addition, about 70% was used as feed. At present, contamination of mycotoxins in corn was paid increasing attention and became the hot issue in food safety area. Due to climate and storage methods,31 million tons of grain contaminated by mycotoxins every year in Shandong province. So it is important to investigate the detection technology and pollution research of corn in Shandong province.This paper took Shandong for example to investigate the main cause and the harm of the risk factors that affect the quality and safety of corn, and offered several suggestions to guarantee the quality and safety control of corn. To study the contamination of mycotoxins of corn, assess the security risks of pollution, and provide the basis for strengthening the prevention and control of mycotoxin contamination in Shandong Province, the study analyzed the 9 kinds of mycotoxins such as aflatoxin(AFB1, AFB2, AFG1, AFG2), fumonisins(FB1, FB2, FB3), deoxynivalenol and zearalenone in corn contaminations.The main research methods and results were as follows:1. A fast analytical method for the simultaneous determination of 9 toxicological important mycotoxins, such as AFB1, AFB2, AFG1 and AFG2; FB1, FB2 and FB3; ZON and DON in corn using a novel Dispersive Solid-Phase Extraction (DSPE) method and Ultra-performance LC coupled to tandem quadrupole TOF-MS (UPLC-Q-TOF/MS) was developed and validated. Samples were extracted with acetonitrile-water (84:16 v/v, containing 1% acetic acid) by means of ultrasonic extraction. The extract was purified with a novel modified dSPE method. The final clear extracts were blew to near dryness under nitrogen and redissolved with MeOH:H2O (5/5, V/V). And then analyzed by LC-ESI-MS on a Thermo Hypersll GOLD C18 column with 0.1% formic acid in ammonium acetate/methanol as mobile phase with gradient elution. Mycotoxins were identified by the retention time and the accurate molecular mass number and the quantification of mycotoxins was carried out by TOF MS extract ion peak area.(1) The results indicated that the quality of 9 kinds of fungus toxin accuracy are less than 4ppm, correlation coefficient R2 were greater than 0.99, and the mean recoveries were ranged from 68.0% to 120.0% and RSDs ranged from 0.18% to 6.29% that were all less than 10%.(2) Limits of detections (LODs) of the 9 mycotoxins were AFB1 (0.05?g/kg)?AFB2 (0.05?g/kg)?AFG1 (0.05?g/kg)?AFG2 (0.05?g/kg)?FB1(5?g/kg)?FB2 (5?g/kg)?FB3 (5?g/kg)?ZON (12?g/kg)?DON (50?g/kg), respectively.(3) The limits of quantification (LOQs) of the 9 mycotoxins were AFB1 (0.1?g/kg)? AFB2 (0.1?g/kg)?AFG1 (0.1?g/kg)?AFG2 (0.1?g/kg)?FB1 (15?g/kg)?FB2 (15?g/kg)?FB3 (15?g/kg)?ZON (25?g/kg)?DON (200?g/kg), respectively.The results showed that method had the characteristics of efficient, accurate, time-saving, and it is suitable for the daily detection of mycotoxins in corn.2. The developed method was applied to 520 corn samples and the results showed that:(1) 18.08% of the corn samples were contaminated with AFB1,7.88% with AFB2,0.77% with AFG1,92.50% with FB1,88.08% with FB2,83.85% with FB3,26.35% with DON, 14.62% with ZON, whereas none of corn samples was contaminated with AFG2. The average concentrations of AFB1, AFB2, AFG1,FB1, FB2, FB3, DON and ZON were 7.62?g/kg, 0.60?g/kg,0.05?g/kg,1798.69?g/kg,531.83?g/kg,197.71?g/kg,240.44?g/kg,74.90?g/kg, respectively.(2) In addition, the results indicated that FUN contamination in corn was one of the most severe problem. The over standard rate was 33.46%.